Modern WisdomHarvard Professor: “I Tried Every Diet. This Is By Far The Worst.” - Daniel Lieberman
EVERY SPOKEN WORD
130 min read · 26,254 words- 0:00 – 2:12
How Diet Shapes the Way You Think About Food
- CWChris Williamson
You've spent years researching every major diet and trying many of them yourself. I want to go through and review all of those. But first off, what was that journey like?
- DLDaniel Lieberman
Well, it was fun. I mean, um, I, I, I've been working for quite a few years on, on a book about the evolution of diet, and I thought rather than just simply studying them, which was the majority of the book, uh, I thought I should try them as well. So kind of, you know, on and off as I was working on the book, my, my wife, who joined me for many of these diets, kept trying some of these, you know, diets. Some of them, some of them better, some of them worse. But just kind of give a little, first of all, some participant observations, so I get a sense of what these diets are like, but also to kind of add context and experience them for myself.
- CWChris Williamson
What did you start that journey believing about food that you no longer agree with?
- DLDaniel Lieberman
[laughs] Um, gosh, uh, that's... I changed my opinions about so many things. I mean, the reason I started this book, um, and this, and this journey, as you say, is that, um, I'm actually-- my research is mostly on physical activity. I'm, I, I study the evolution of running and walking and throwing and, and various other physical activities, but I also teach nutrition and digestion and physiology and, you know, that kind of stuff. And I read the literature, and a few years ago, actually with some f- uh, colleagues, I taught a course on diet and exercise, and I've just been so confused by what I read, right? Because one, you can read it in the New England Journal of Medicine, you know, the arguably the top journal in the world, articles in the same year that tell you that saturated fat is good for you, and then articles that tell you saturated fat is bad for you. You know, this much salt is too much for you, and this much salt is actually just perfect for you. I mean, you, you name it, there's controversy and confusion.
- CWChris Williamson
Mm-hmm.
- DLDaniel Lieberman
And so I wanted to explore those problems myself. Um, but, uh, as an evolutionary biologist, I wanted to integrate an evolutionary perspective, an evolutionary lens, with hardcore biomedical data, cultural data, anthropological data, experiential inf- uh, you know, information-
- CWChris Williamson
Mm
- DLDaniel Lieberman
... all that together to think about it i-i-in a whole. So, so my... So I was really trying to do this in order to answer questions for myself.
- 2:12 – 2:55
Diet Through the Lens of Human Evolution
- CWChris Williamson
What use does an evolutionary lens give you that is typically missed when people make assessments about diet and nutrition?
- DLDaniel Lieberman
Oh gosh, it's hard to know where to start. There's a famous expression in my field that nothing in biology makes sense except in the light of evolution. It was written by a guy named Theodosius Dobzhansky in nineteen seventy-two, and what he meant was that we didn't-- we weren't engineered, we weren't designed, we evolved. And if you understand why things are the way they are, you need to take an evolutionary perspective, right? Uh, so evolution answers a lot of why questions, and when you start addressing why questions, you begin to think differently also about how questions and what questions. So, so I, I mean, so nothing makes sense except in the light of evolution, and diet is no exception.
- 2:55 – 5:56
Do We Look For Meaning Through Diet?
- CWChris Williamson
Hmm. It feels like nutrition and diet are a little bit like new religions.
- DLDaniel Lieberman
[laughs]
- CWChris Williamson
There's dogma. It's a super sensitive topic. People get tribal. It's often impossible to change their belief, no matter how much evidence you give them. Why do you think that's the case?
- DLDaniel Lieberman
Yeah.
- CWChris Williamson
Why do people become so ardent?
- DLDaniel Lieberman
That's, that's... I completely agree with you. And in fact, I think that one of my biggest takeaways from working on the book was just how tribal people are about their diet. And I, and I, I ha- I don't know the, the answer, but I suspect it has-- goes something along the lines of this, which is that for, for millions of years or thousands of years, depending on which timescale you want, people ate w- the way their culture dictated, right? If you lived in the Middle East, you'd eat like a Middle Easterner, and if you lived in Japan, you'd eat like a Japanese person. And now we live in a world where everybody kind of eats the same stuff. And, um, and a lot of, uh, institutions are sort of crumbling, and I think people are searching for identity, and I think one of the ways in which we define ourselves is by what we eat-
- CWChris Williamson
Hmm
- DLDaniel Lieberman
... or very often by what we don't eat, right?
- CWChris Williamson
Mm-hmm.
- DLDaniel Lieberman
And that's been sort of the case all along. You know, if you're kosher, you don't eat this, if you're-
- CWChris Williamson
Yeah
- DLDaniel Lieberman
... if you're Jain, you don't eat that, et cetera, et cetera. But, but I think, um, uh, people are searching for, for meaning and identity, and diet is a really important way of defining that. A lot of the, a lot of diet, um... I mean, some diets are kind of like cults. I mean, um, they're sort of online-
- CWChris Williamson
Nutritional theology
- DLDaniel Lieberman
... they're, uh, kind of online cults, and everybody kind of agrees. It's kind of like groupthink.
- CWChris Williamson
You know why I think at least part of it is because we all understand that the diet that we eat is related to longevity. What we are faced with when somebody says that they disagree with our... or they di-diverge from what it is that we're eating, it's kind of a threat against our own existence that if this person is right, implicit in that, if I believe deeply about my diet, and they believe deeply about theirs, and we diverge in our opinions, that means maybe they're gonna live longer than me, or that means that maybe I'm gonna die sooner, or that means that I'm wrong in some sort of a way. It's not an abstract discussion.
- DLDaniel Lieberman
Yeah.
- CWChris Williamson
It's go- it's gonna have real world implications.
- DLDaniel Lieberman
It is. Absolutely.
- CWChris Williamson
It's gonna come into land at some point.
- DLDaniel Lieberman
Yeah, but I think the, one of the key words you just h- said is belief, right? Because one of the real problems about diet is that it takes years, many years, for the effects of diets to manifest themselves in terms of our health. And so we all have to take leaps of faith when we pick our diet, right? I mean, right now I'm... You know, m- let's just say I follow the, the Mediterranean diet. You know, I can read all the, the studies I want about how good the Mediterranean diet is for me, but I won't know for thirty, forty years-
- CWChris Williamson
[laughs]
- DLDaniel Lieberman
... maybe fifty years [laughs] if, if it's true, right? So we all have to take a leap of faith to some extent when we pick a diet. Some people take leaps of faith based on their friends, their, the group, the community.
- CWChris Williamson
Hmm.
- DLDaniel Lieberman
Others are a little bit more scientific. But, uh, no matter who you are, you have to figure out what you believe and how you're gonna... or what information you're gonna use,
- 5:56 – 11:30
Are Plant-Based Diets Actually Better?
- DLDaniel Lieberman
uh, to credit.
- CWChris Williamson
Okay, let's get into some of the religions. Maybe two of the most ardent groups are vegans and carnivores.
- DLDaniel Lieberman
[laughs]
- CWChris Williamson
Are plant-based diets superior?
- DLDaniel Lieberman
You know, I try not to be that judgmental about anything. I mean, if you look at the data, um... Look, no matter what you-- E- everybody who has a particular diet idea, and including the fad diets, almost all of them are based on some grain of truth, all of them, the carnivore diet included. However, when you look at the data and you look at, like, big meta-analyses, large-scale studies, um, I don't think there's much contest that, you know, plant-based diets of various sorts, and they're not all the same, uh, tend to have better health outcomes, uh, in terms of meta-analyses, long-term studies, and there's also mechanistic data as well. So, uh, I think if you're gonna err on the side of animals versus plants, I, I think the, uh, science is pretty clear, plants.
- CWChris Williamson
Why?
- DLDaniel Lieberman
Gosh, there are a lot of reasons for that. Um, well, one is that plants, um... Again, not, not all plants are the same. If you eat crap plants, right? If you eat sugar and, you know, highly refined grains and carbohydrates, you're not eating a very healthy diet. I mean, a lot of ultra-processed foods are mostly plant.
- CWChris Williamson
Hmm.
- DLDaniel Lieberman
Um, that doesn't make them... The fact that they're plant-based doesn't make them healthy. Um, but so, so, so y- so, y- you know, it's, it-- When we oversimplify, we can get ourselves into trouble. But, um, but there's evidence that, that, um, meat for... Even though we evolved to eat meat, meat has been, played an important part in our evolutionary history. Meat is nutritious, um, there's no question about that. But, for example, there are studies which show that there's a dose-response effect between how much meat you eat and your risk of cancer. Um, I think it's, um, like one serving of meat, which I think they count as 85 grams, increases your, your, your risk of cancer over the, over X years by, I think, 13%. And if you, if you double that, y- it, you double the risk, so there's a, there's a dose-response effect. So that's a, that's, this is epidemiological data, and there are quite a few studies which show that. Secondly, there are mechanistic studies, right? So we know, for example, that meat has a protein called carnitine, and carnitine, when it goes to your gut, is transformed into another molecule called TMAO. Don't ask me to give you the long form of the, of the, of the molecule. And TMA- TMAO is a known, uh, inflammatory m- molecule that causes inflammation and has been associated with risk of, of, um, um... Actually, it's been shown to be mechanistically related to atherosclerosis, to hardening of the arteries, so increased blood pressure. Um, another effect of meat is that, that, uh, red meat, not, not, um, not poultry or fish, has a, has a glycoprotein. So a glycoprotein is a little... You know, every cell has these little kind of like forest of, of like sugar protein molecules that stick off, and red meat has a particular kind of glycoprotein called Neu5Gc. [chuckles] I mean, that doesn't really matter, but the, the name. But turns out that humans have an inflammatory response to that. Um, we alone-
- CWChris Williamson
All humans?
- DLDaniel Lieberman
All humans. There's a gene called CMAH which c- causes us to, um, to, to transform one proteoglycan into another kind, and that makes us, um, have a response to any red meat. And, um, and that's also been argued to be another mechanistic reason for the, the data I mentioned earlier, that there's a relationship between dosage of meat eating and, and cancer risk. But again, it's not so simple because everything has trade-offs, right? There's no such f- food that doesn't have a trade-off. Um, and, and meat is just one of them. And, uh, so, uh, the other... Of course, the issue about meat is that meat tends to, not always, but tends to have a higher amount of saturated fat, and saturated fat [clears throat] is one of the most [chuckles] controversial things on the planet, right? In, when-- Especially when it comes to nutrition. And, and we all don't, we don't... Y- y- there's a lot of variation in how we respond to, to saturated fat. Some of us can eat as much saturated fat as we want, and it doesn't really have any negative effect. But others, um, do have some genetic susceptibility to s-saturated fat, and it does raise their, the risk of, or raise the levels of, of lipoproteins or cholesterol molecules that cause, um, heart disease. So it's complicated. Um, there's, there's just never a simple answer for anything.
- CWChris Williamson
It's seems like maybe some of the reasons for plant-based diets having better outcomes, at least epidemiologically, is not maybe to do with what's in the plants, but what's not in the meat that isn't being eaten. It's like the-
- DLDaniel Lieberman
Of course
- CWChris Williamson
... the elimination diet of meat as opposed to the inclusion diet of plants.
- DLDaniel Lieberman
Of course. I mean, that's part of the problem with studying nutrition, which is that every time you don't eat something, you're eating something else, or every time you eat something, you're not eating something else.
- CWChris Williamson
Yeah.
- DLDaniel Lieberman
Or almost. So, so that's one of the reasons why, you know, you can't do a study, right? I can't, I c- there's no one is ever gonna do a study where they take, you know, 100 groups of twi- 100 sets of twins and have one group of twins eat an all-meat diet-
- CWChris Williamson
Hmm
- DLDaniel Lieberman
... [chuckles] and one group of twins eat an all-plant diet. And even if they did do that, how would you separate all the other effects, right? Because when the ones are eating the meat diet, what is it they're not eating? And the ones who are eating the plant diet, what is it they're not eating?
- CWChris Williamson
Yep.
- DLDaniel Lieberman
And so on, and how do you correct for the effects of exercise and, and, and smoking and, you know, all those other factors. It's, it's not possible to do that.
- 11:30 – 14:04
Why the Carnivore Diet Is Taking Off
- CWChris Williamson
Why is it that the carnivore movement has had such a boon recently if some of the data seems to be skeptical about the kind of outcomes of a very heavy meat-based diet?
- DLDaniel Lieberman
You know, that's a bit of a mystery to me. I mean, I think part of it is, again, it's a, a bit tribal. I think meat is associated with manliness and, and, you know, masculinity. Uh, that's explains I think some of it. Uh, in the book I, I recount, um, you know, James Blunt, the English s- uh, singer-
- CWChris Williamson
Yes
- DLDaniel Lieberman
... went on an all-meat diet and ended up getting scurvy. But he describes, [chuckles] um, he describes that, um, that the reason he did it is he thought it made him more manly. Um, now, I mean, that, that meant... That's probably not everybody. Um, there are others who t- you know, they, they, they hear, um- Uh, podcasts or, or, or whatever that, uh, that, that, um, um, that expound the, the benefits of, of a meat diet and, uh, they're attracted to it for one reason or another. And, and, and, um, you know, one other, other issue is that a lot of people are on really unhealthy diets, and if you pick pretty much any diet that's not a crap diet, for lack of a better term-
- CWChris Williamson
Yeah
- DLDaniel Lieberman
... you're gonna do better. [chuckles] And so you might think, "Okay, wow, I'm eating all this meat. I'm feeling better than when I ate lots of McDonald's and drank... swilled lots of, you know, soda and, and whatever." It doesn't mean that you'd do... wouldn't do even better on, say, a Mediterranean diet or a DASH diet or a Blue Zones diet or a-
- CWChris Williamson
Hmm
- DLDaniel Lieberman
... you know, fill-in-the-blank diet.
- CWChris Williamson
Are you saying that the best diet is the one that you're able to stick to?
- DLDaniel Lieberman
Well, it depends what your goals are. Um, if you're trying to lose weight, absolutely. I mean, that's actually... There's something called the National Weight Loss Registry, where they've actually analyzed, uh, again, 'cause you can't randomize huge numbers of people to different kinds of diets perfectly. So what this study has done is that they've looked at... They've tracked people who've managed to lose weight and keep it off for a long period of time. I think the average for the respondents is at least six years or something like that, 5.6 years or something like that. And, and, um, and people's diets are kind of all over the place, but the, but what they all share is they're not junk food diets. They're tending not to eat a lot of sugar and a lot of, you know, added fat and things like that, and they're able to stick to them, um, s- um, because, because, you know, a lot of people find diets hard, right? Um, if you go for a low-fat diet, I mean, it's... I tried a low-fat diet. It's not [chuckles] it's... I... Fat makes food tasty, you know? Going on a low-fat diet is really hard, and a lot of major studies have failed, uh, n- n- um, to have very much effectiveness because people can't tolerate the diet. They, they, they, they just start eating more fat.
- 14:04 – 19:50
The Truth About Proteinmaxxing
- CWChris Williamson
What do you make of the current protein maxing push-
- DLDaniel Lieberman
[laughs]
- CWChris Williamson
... given what sounds to me like a degree of skepticism around the importance of meat? Protein is the new hot girl in school. Everybody wants her. Everybody's having more of her. What do you make of the current-
- DLDaniel Lieberman
Well-
- CWChris Williamson
... world of protein consumption?
- DLDaniel Lieberman
I mean, I find it fascinating. I mean, protein's having its day, and you look, there, there's some truth to the, the interest in protein. Protein is important. It's... You need protein. Uh, there's... Every day, you need protein. You can live without eating fat, and you can live without eating carbohydrates, but you cannot live without eating protein.
- CWChris Williamson
Is that true?
- DLDaniel Lieberman
Absolutely, yeah. Your body can turn anything into fat, and your body can turn, uh, it can... Your body can transform, um, uh, fats and proteins into sugars, uh, but you cannot... Uh, there are a bunch of amino acids that are essential. You have to have them in their diet or you'll die. There's actually two fatty acids that you need to eat a little bit of, um, omega-3 and omega-6. But apart from that, um, you, you do need to eat protein. Secondly, protein is filling, so, um, uh, so people tend to be a little bit more sated on eating protein. Protein takes a little bit more energy to digest, um, and, and it's pretty nutritious. But here's the thing, um, uh, and I think a lot of people, um... And if you're, you know, very physically active, if you're menstruating, if you're pregnant, um, you need, you need extra protein. As people age, they also lose muscle mass, and it's really important for them to have protein. But here's the thing, the body can't store extra protein. If you eat more protein than your body can use, you can't store it, so what do you do? You turn it into, you turn it into fat. So eating massive amounts of protein, um, is probably not that harmful unless you get to ridiculous levels and you can do kidney damage, but you have to really eat a lot of protein for that. So eating huge amounts of protein i, is not gonna have some massive benefit, and there's no ev- I, I don't... I've never seen any strong evidence to the, to that say.
- CWChris Williamson
One gram per pound of body weight-
- DLDaniel Lieberman
That-
- CWChris Williamson
... it's the rubric used.
- DLDaniel Lieberman
That's what they say, yeah.
- CWChris Williamson
And what do you... Where do you come in to land on one gram per pound of body weight for protein consumption?
- DLDaniel Lieberman
I don't have a strong opinion on that. I mean, I think, [chuckles] you know, we're all different. I mean, part of the problem with the way we think about diet is we, we, we medicalize it, right? You know, that... You just gave a dose, right? Uh, but it doesn't work that way. Um, it's, it's complicated. It depends on what you're doing and how old you are and whether you're losing muscle and whether you're working out and whether you're 20 or whether you're 80.
- CWChris Williamson
Hmm.
- DLDaniel Lieberman
Um, um, uh, I don't think anybody's able to come up with a perfect dose of protein. I mean, it, it's, you know, the old definition of economical, you know, enough but not too much, and I think that... And we all have to figure out, that out, but, but it's not, you know... Uh, it's, it's really hard to come up with a very simple diagnosis for any human being, and that's, again, part of the problem with diet. We all, we all want to be told what to do.
- CWChris Williamson
Hmm.
- DLDaniel Lieberman
We all want to make it simple. We want a magic bullet. We want a quick fix, and p- the problem with diet and nutrition is that it doesn't work that way.
- CWChris Williamson
I imagine we're only two religions in to our-
- DLDaniel Lieberman
[laughs]
- CWChris Williamson
... uh, nutritional theology-
- DLDaniel Lieberman
[laughs]
- CWChris Williamson
... uh, trip around the world. I imagine some people are already feeling a, a, a degree of maybe uncertainty or confusion. Why... Okay, so it's important for me to have protein, that I need that. It's actually mandatory. It's one of the few things that I have to have, or else I'm gonna die at some point. But also, there's some pretty sort of negative effects, especially around red meat, it seems, although long-term populations. The plant-based thing appears to maybe win out a little bit, but the carnivore thing is missing some stuff.
- DLDaniel Lieberman
Well, well, what, what... But, but one of the weird things about the whole protein thing is that people seem to associate protein with meat. You know, when you go out, uh, all, uh, all those plants out of there, they're, they're... [chuckles] There's a, there's a lot of protein in those plants. Beans are filled with protein. Legumes are filled with protein. Um, uh, whole grain foods have a lot of protein. You don't need meat in order to get protein, and in fact, you know, soy is a complete protein. You could actually live your life off soy. You don't actually need to eat meat in order to get protein.
- CWChris Williamson
Hmm.
- DLDaniel Lieberman
So the equation of meat with protein, I think, has been, uh, uh, exaggerated. It's true, meat is- Rich in protein, and meat is a complete protein. But you can also get a lot of protein from quinoa and from, you know, from nuts and whatever. You know, it's not a... You, and you can certainly buy... And, and every culture on the planet has figured out, you know, every farming culture on the planet figured how to get sufficient amounts of protein by combining a grain with a legume, so rice and beans or corn and beans. All of those are ex- are solutions that, that cultures worldwide figured out in order to help ma- ensure that people got adequate amounts of protein.
- CWChris Williamson
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- 19:50 – 24:00
Is There Really One “Best” Diet?
- CWChris Williamson
Mediterranean diet is regarded as one of the most healthy on the planet. Is that right?
- DLDaniel Lieberman
It has probably more scientific evidence, um, to support it than any other diet because... And that's partly Eurocentric because, of course, you know, Europeans and Ame- uh, do most of the research, and Americans do most of the research, so there's a lot of, there's a lot more data on it. I'm not sure that the Mediterranean diet is necessarily healthier than a traditional Asian diet or a traditional American diet or tr- you know, Mesoamerican diet or a traditional Asian diet. But absolutely, there's a ton... I mean, if you were gonna go purely on epidemiological data, uh, at the moment, you would pick a Mediterranean diet.
- CWChris Williamson
Can you explain what epidemiological data in the world of diet and nutrition means?
- DLDaniel Lieberman
Excellent question. So, so there's n- a number of ways to figure out the effects of food and diet on health. And so one is to do... Uh, I'm gonna back up a little bit, if you don't mind. So one of them is do a randomized control study. That's the gold standard, right? I give you and your twin two different diets, and I follow you for X number of years, right? And then I can measure its effect on your cholesterol levels and your, this, you know, your steroid levels and your, you know, your nasal mucosa production, whatever. You know, I can measure anything I want, right? But of course, it takes a long time to do that. And so because we can't wait for you to die, um, we're going to then measure proxies, right, uh, rather than your actual health outcome. The other is to take large samples of a people and then try to as- make associations between what they eat and their health outcomes.
- CWChris Williamson
Hmm.
- DLDaniel Lieberman
And that's what an, that's an epidemiological study. So, so there are statistical associations within a population between say what people eat and their likelihood or their prevalence of getting heart disease or hypertension or cancer or arthritis or whatever it is. And so for, um, the Mediterranean diet, there are both epidemiological studies, large scale ones, huge. I mean, there are now meta-analyses involving hundreds of thousands of p- of individuals, but there are also prospective studies. So that's... The kind of the gold study is when you take a bunch of people and you, again, randomize them into two groups. So one of the biggest studies was one done in Spain, for example, where they had over 7,500 Spaniards, and they assigned some of them a, a Mediterranean diet where they had to have olive oil or, or walnuts, there were two arms to that, versus Spaniards who were not eating a Mediterranean diet. And after, um, I think after five years, they stopped the study because the effects, the beneficial effects of the Mediterra- Mediterranean diet were so high that they felt that it was unethical to continue the study and, and, and not get-
- CWChris Williamson
Deny the other group-
- DLDaniel Lieberman
Correct
- CWChris Williamson
... from the benefits of having a Mediterranean diet.
- DLDaniel Lieberman
That's correct. That's correct.
- CWChris Williamson
Wow. It was so good that a-
- DLDaniel Lieberman
It was called the PREDIMED study
- CWChris Williamson
... a non-Mediterranean diet was es- essentially seen as kind of a toxic in-
- DLDaniel Lieberman
As unethical. As unethical.
- CWChris Williamson
No way.
- DLDaniel Lieberman
Yes way. So, uh, so that's just one study.
- CWChris Williamson
That is wild.
- DLDaniel Lieberman
Um, there's other studies in France, elsewhere. So these are... And again, these are prospective studies, so those are the, the best studies, right?
- CWChris Williamson
Right.
- DLDaniel Lieberman
Now, every study has its drawbacks and its problems and its flaws, right? You can't, you know, 'cause you have to account for, for, you know, all the other things that people are eating, their smoking, their physical activity, you know, whether or not they're, you know, whether they're lawyers or not, who knows what. But, uh, but when you combine all those different... And, and but there's... And then on top of that, there are studies where you can feed people a Mediterranean diet for just a few weeks in a lab, for example, and then measure its effects on, on, on, on aspects of your health that have a outcome like, like a cholesterol level, right? Or, or, or so on. And, um, um, or markers of inflammation.
- CWChris Williamson
Hmm.
- DLDaniel Lieberman
And so you combine all those kinds of data together, the mechanistic studies, the epidemiological studies, the prospective studies, and the Mediterranean diet comes out as a very, you know, I probably... I wouldn't say it's the clear winner, but it's, uh, you know, it's, it's, it's, it's probably has the most evidence in its favor of any diet that's
- 24:00 – 31:46
Can We Trust Epidemiological Studies?
- DLDaniel Lieberman
ever been studied.
- CWChris Williamson
I imagine when it comes to the epidemiological studies, people's dietary choices are idiosyncratic. They're informed by the culture that they're from and the w- the job that they have. You know, if you're... There's an entire industry of PTs that are probably overeating meat, which means that you have meat eaters that are disproportionately personal trainers, but that means that they have the lifestyle of a personal trainer. Or perhaps there's something cultural that, you know, red meat is eaten by, uh, dudes that like to barbecue from the Deep South, and maybe they're doing other stuff with their health, and maybe they're smoking or whatever. So the, the, uh, selection effect Of what people eat which diets and what are the things that aren't under the study's, uh, purview, and what does that sort of-
- DLDaniel Lieberman
Huge, huge effect. Like, you know, vegetarians also tend not to smoke, right? And, and so how do you separate the fact of b- eating a vegetarian diet from the fact that you, you're much more likely to smoke? And people who, uh, tend to be, um, th- the more physically active also tend to eat a healthier diet. In fact-
- CWChris Williamson
Mm
- DLDaniel Lieberman
... you know, big studies where they g-... Like, when, when you and I die, right, there's gonna be a death certificate, right, saying we died of such and such. And it might be, you know, cancer or a heart attack or whatever, but then what was it that caused the cancer? What caused the heart attack?
- CWChris Williamson
Right.
- DLDaniel Lieberman
Th- and that's, there's a, there's a, a, a bunch of epidemiologists out there trying to f- try to figure that out, and many studies are unable to separate statistically the effects of exercise and diet-
- CWChris Williamson
How-
- DLDaniel Lieberman
... because people who exercise tend to eat well-
- CWChris Williamson
Mm-hmm
- DLDaniel Lieberman
... and vice versa.
- CWChris Williamson
Mm.
- DLDaniel Lieberman
So, so the covariation-
- CWChris Williamson
Is that health, healthy user bias?
- DLDaniel Lieberman
Exactly. So the covariation is, what we call covariation, is so strong, statistically it's very difficult to separate these things.
- CWChris Williamson
Does that make epidemiological studies in nutrition and diet largely useless, then?
- DLDaniel Lieberman
No. They're, [laughs] they, so that's the wrong way to think about it. Eh, epidemiological studies cannot measure cause and effect, but they are one of many forms of i- of information that we can and should use. Because again, you can't... I mean, like, again, the gold standard study for a true skeptic is a randomized control study, but as we had talked about before, you can't do a proper randomized control study and wait 50, 60 years for somebody to, to see the effects of the diet and control for everything else, too.
- CWChris Williamson
Mm.
- DLDaniel Lieberman
So we, we need to be... The... Do you know the, the, the analogy of the hedgehog and the fox?
- CWChris Williamson
No.
- DLDaniel Lieberman
Okay. So there's a famous, uh, piece of paper from the seventh century BC by a guy named Archilochus of Paros, which wrote... He, he wrote... And it's like a fragment. He's a po- like, a boring poet, but, but apparently he, he wrote this, like, bit of a poem that survived, and it says, um, "The fox knows many things, but the hedgehog knows one big thing." And what he meant by that was that when you chase a fox, it'll do anything to run away, right? It'll hide, it'll, it'll, you know, it'll, it'll c- take-
- CWChris Williamson
Climb a tree
- DLDaniel Lieberman
... climb a tree. It'll do whatever, right? You chase a hedgehog, it just rolls into a ball, right? Hedgehogs just do one thing. And that analogy was used by a very famous, uh, English philosopher named Isaiah Berlin to think of, to kind of divide the world up into hedgehogs and foxes. So, so f- hedgehogs are w- big idea guys. Like, they... Protein is your answer. Um, you know, e- meat is your answer. Um, never eating meat is your answer, et cetera. Those are what I call hedgehog diets. They're single idea, big fix diets. Whereas foxes are the... see nuance. They see trade-offs, they see complexity. They realize that every time you eat one thing, you don't eat something else. And, and, um, and, and we need to apply... I, I think that, you know, the hedgehog approach to diet is always the wrong way, because it's complicated. People vary. The effects of foods are complicated.
- CWChris Williamson
Mm.
- DLDaniel Lieberman
There are trade-offs, and when we start to oversimplify, we inevitably get things wrong, and that's true for even how we analyze the scientific r- record. If we decide, well, epidemiological data, it's just junk because you can't test cause and effect, you're missing important information. Just as if you decide, oh, you know, randomized control studies are really problematic because they're too short term and they don't involve variation or whatever, you're also missing something important.
- CWChris Williamson
Mm.
- DLDaniel Lieberman
The best approach is to look at as much of the information as possible and put it together, and that's... [laughs] I mean, if I can be a little, you know, self-promoting, that's why I wrote the book, 'cause I tried in Fed Up to, to take all that evidence and to digest it, put it into kind of plain English, and make it, uh, d- you know, uh, help people understand that. Because I think all of us need to try to answer these questions. Y- let me put it, let me put it another way. For millions of years, millions of years, our ancestors, they had to know an enormous amount to get their food, right? If you're a hunter-gatherer, you kn- you have to know how to hunt animals, right? You need to know, um, you know, where they are and how to track them and how, you know, what's the right, you know, w- what environments they're gonna be in, and, and how to butcher them, and all that kind of stuff. To find plants, I mean, I've gone out foraging and hunting with hunter-gatherers. Finding plants is not a trivial matter, right? Finding where the plants are, knowing how to dig for them, and knowing where they are at different seasons. We had to be naturalists. We had to know a huge amount of information in order to survive. Now, you and I can walk into a Whole Foods or whatever, you know, whatever's, you know, Sainsbury or whatever, whatever it is, and we're confronted with 40,000 different kinds of food. We don't know how to... We don't need to know how to get our food anymore. We now need to know how to choose our food. So we, we need a different kind of knowledge, and, and you can, you can throw up your hands and just have somebody tell you what to do, or you can try to learn for yourself what you, what you want, what you care about, what's important to you, what your trade-offs are.
- CWChris Williamson
Mm.
- DLDaniel Lieberman
So I think all of us need to educate ourselves to, to figure out how to choose our food, because that's the challenge our modern world has set us.
- CWChris Williamson
The question of what should I eat today evolutionarily is pretty novel that-
- 31:46 – 34:36
Why the Mediterranean Diet Keeps Winning
- DLDaniel Lieberman
that.
- CWChris Williamson
Going back to the Mediterranean diet, what is it about that diet that seems to... What, what's the mechanistic reason for why it seems to outperform others?
- DLDaniel Lieberman
Um, there's probably a number of reasons. Um, there's, again, there's no one reason. Um, so one is that it tends to be whole grain, right? So you, so when you take w- uh, flour and you refine it, right, you remove the, the outer layers and you remove the germ, you're removing a lot of the protein and you're removing a lot of the fiber. Um, it's, um, it's, it has a, um, a he- a healthy balance of fat, so of course it's famous for olive oil, which is a monounsaturated fat. We can talk about that if you want. And monounsaturated fats are associated with a lot of health benefits. There's a lot of fruit, a lot of vegetables. Mediterranean diet often has fish in it, and fish has these omega-3 fatty acids. Um, so it's the constellation of h- of n-nutrients that are healthy, plus an absence of a lot of stuff like added sugar and a lot of-
- CWChris Williamson
You can say what, what are the things that it eliminates most?
- DLDaniel Lieberman
Well, it tends not... You t- Mediterranean diet tends not to have a lot of added sugar, right? Tends not to have that much, um, a proper Mediterranean-- 'cause what you define as a Mediterranean [chuckles] diet is, you know, can be, can go all-
- CWChris Williamson
Neo-Mediterranean
- DLDaniel Lieberman
... all over the, uh... What, what the, what the... Mediterranean with a capital M, capital D, right, which is what's been defined by, um, by the, by the nutritionists, isn't necessarily what people always eat in the Mediterranean. I've spent, I don't know, a lot of really carb-rich dinners in, in Italy, for example. But, um, but it, you know, tends not to have added sugar, tends not to have a lot of refined carbohydrates, tends not to have a lot of saturated fat, tends to be diverse and rich in, in, in phytochemicals that are healthy and, you know, have a lot of antioxidants and things like that, tends not to have too much red meat. Uh, so it's a, it's, it's a mixture of things that have, in toto, been shown to, to be reasonably healthy. Now, is it a, is it a, is it like an optimal diet? Is it perfect? It'll guarantee perfect health? No. Uh, n-no diet is optimal. But is it-- does it, has it been shown to be effective for preventing weight gain and for reducing your risk of a wide range of diseases? Absolutely.
- CWChris Williamson
How much is it the lifestyle? I've heard about the importance of the sociality around the Mediterranean diet and stuff like that. Has that been separated out? You know what I'm talking about, right?
- DLDaniel Lieberman
Yeah, it's... I mean, that's, again, it's very hard to do that. Um, but, but for example, that, that study I mentioned, the Spanish study, the Predimed study, I mean, that, that essentially by randomizing people who all presumably had similar lifestyles, th- they were, they were prescribed-
- CWChris Williamson
They're hanging out on the street corner having a coffee at 9:00 p.m. at night, they're with their friends and-
- DLDaniel Lieberman
But that, but both arms of the diet were probably the same.
- CWChris Williamson
Yeah. Yep, yep, yep.
- DLDaniel Lieberman
So, so that, so that study, for example, controlled for that. Um, so... But of course, there's more to, to health and longevity than just your diet.
- 34:36 – 42:18
The Blue Zones Myth Explained
- CWChris Williamson
What about Blue Zone diets?
- DLDaniel Lieberman
Oh my God, don't get me started on that one. [laughs] I mean, Blue Zones are fun. I mean, look, there's a lot to say about Blue Zone diet. The first is, again, uh, you know, if you-- it's kind of like a Mediterranean diet, but with even less meat, if you're, if you look at what it prescribes, you know? And, but it also prescribes, um, skipping breakfast. Um, it tells you to be social. Um, it tells you to, uh, not finish your plate. Um, you know, there's some social aspects to it.
- CWChris Williamson
Yeah.
- DLDaniel Lieberman
But, but what's... I find... [laughs] And you know, if you look at the in- the, the, the, the, the, the, the sort of prescription of the diet, especially nutritionally, it's kind-- what a lot of... You know, it's not far off from the Mediterranean diet. Um, I don't know of any really good high quality studies for the Blue Zones diet compared to, say, the Mediterranean diet. But what I find amusing about the Blue Zones diet is how it's been advertised, 'cause it's advertised and marketed as a diet that'll help you live to be 100. And that's where I begin to have some concerns, because even if you look at the data for the Blue Zones, like if you... There's these supposed Blue Zones, these, these five regions on the planet where-
- CWChris Williamson
Where are they?
- DLDaniel Lieberman
Let's see. One of them is in the Nicoya Peninsula of, of Costa Rica. One's a little, kind of little village in Sardinia. It's like a little area in Sardinia. One is, uh, an island in the Mediterranean. I've forgotten the name of the island. Um, one is, uh, Okinawa, and the other is Loma Linda, California [laughs] right outside of LA. No, I'm kidding.
- CWChris Williamson
Okay. I didn't know that one was in there.
- DLDaniel Lieberman
And those are the five Blue Zones. And, and the idea behind these are these are supposedly areas where a hi- twice as many people live to be centenarians. They live to be 100 years old. And so the idea is if you eat like the people in these areas, you too are gonna live to be 100 years old. Now, there's some problems with this. The first is [laughs] that even if you believe the data that, that these, these regions have a h- have a higher percentage of centenarians, it turns out that the percentage of centenarians is tiny. So it's like, it's like six people out of 10,000, as opposed to in the United States, where it's three people out of 10,000.
- CWChris Williamson
The base rate's so low that small changes are massive proportions.
- DLDaniel Lieberman
These are statistical outliers. So you're basically, you have to... If you, if you're not a statistical outlier, which most of us are not [laughs] , it's irrelevant. It's not a very... It's statistical nonsense, basically. Secondly, there's a guy in Oxford, who's a, um, a demographer at Oxford, um, I'm trying to remember his name. Saul Newman, I think his name is. He's published [chuckles] this really fascinating paper. He did a deep dive onto these blue zones and found out that only 18% of the people in these blue zones actually had birth certificates. So we don't even know [laughs] who these people are. They just self-report their age, and these are areas... So, and he claims-
- CWChris Williamson
Are you telling me, are you telling me that a good chunk of the Blue Zone fervor could have been around the fact that people just didn't register how old they were?
- DLDaniel Lieberman
Correct, or it could be i- insurance fraud. I mean, I have no idea. Um, yeah, exactly. [laughs]
- CWChris Williamson
[laughs]
- DLDaniel Lieberman
Right?
- CWChris Williamson
I'm sorry. It's just-
- DLDaniel Lieberman
You can get online, you can read Saul Newman's paper. It's a hilarious paper to read. Um, um, uh, but also think about it this way. Like he cl- there's this, like, little area in Sardinia. If, if you go on, if you click on the Blue Zones map, there's this like... You know, think about Sardinia. It looks, you know, it's this kind of oval shaped island, right? And there's this little area on the, on the western side, and there's a little blue, you know, zone on the map, right? Uh, in that little area, you have all these centenarians. Now tell me that if you, like, go, like, 30 miles north or 30 miles south, that people have totally different diets. And it's like, so why in this little spot are they all centenarians, and just 20 miles north or 20 miles south, they're not? It's kind of suspicious.
- CWChris Williamson
What are the, what is the Blue Zone proponent explanation for that?
- DLDaniel Lieberman
Uh, I, I think he's answered... I don't think he's, he's-
- CWChris Williamson
Is it a guy?
- DLDaniel Lieberman
Uh, yeah, it's a guy named, um, what's his name? Um, Buettner, Buettner? I can't remember. He's a, he was a, he was a, um, he was a National Geographic reporter who, who got really excited by this and figured how to market all this. But h- uh, the, one of the most interesting blue zones is Loma Linda, California. Do you know who lives in Loma Linda, California? Why, why, why Loma Linda is a blue zone? 'Cause obviously they're not little, you know, peasanty, you know, farmers eating their traditional foods.
- CWChris Williamson
No.
- DLDaniel Lieberman
They're Seventh Day Adventists, and the Seventh Day Adventists don't believe in smoking. They believe in exercise. They're, you know, they believe that... They're, they're, many of them are vegetarians. They believe that-
- CWChris Williamson
They don't believe in exercise.
- DLDaniel Lieberman
No, they do believe in exercise.
- CWChris Williamson
Oh, they do believe in exercise.
- DLDaniel Lieberman
Yeah, yeah. They, they believe that y- y- that God gave us our bodies, our body is a sacred thing, and that y- it's our responsibility as, um, as, as, as, as Christians to-
- CWChris Williamson
Right
- DLDaniel Lieberman
... to take good care of our God-given body, and so they-
- CWChris Williamson
Oh, that's inter- that, that's, uh, physiological theology. Very good.
- DLDaniel Lieberman
It is. It is.
- 42:18 – 51:57
Can You Lose Weight Without Cutting Carbs?
- CWChris Williamson
Okay, let's piss off some more people. What about-
- DLDaniel Lieberman
[laughs]
- CWChris Williamson
... low carb, high fat?
- DLDaniel Lieberman
Oh boy, am I gonna get in serious trouble after this one. [laughs]
- CWChris Williamson
Yes. Yes. Yes. We both are. It's fine. Low carb, high fat.
- DLDaniel Lieberman
Well, again, there-
- CWChris Williamson
Used to be Atkins, now it's keto.
- DLDaniel Lieberman
Yeah, I mean, look, both... Depends what your goals are, right? Um, it turns out if you wanna, if your goal is to lose weight, for example, you can lose weight on a low carb diet and you can lose weight on a low fat diet. Um, it is true that people tend to lose a little bit more weight on low carb diets than low fat diets. Um, but the, but, um... And in fact, I'm one of the co-authors of the carbohydrate insulin model big paper that was recently in the American Journal of Clinical Nutrition. So I've-
- CWChris Williamson
Congratulations
- DLDaniel Lieberman
I've signed my name in blood on the... And I believe in the biology behind, uh, the low carb diet, so we can-
- CWChris Williamson
Can you explain that in layman's terms?
- DLDaniel Lieberman
We, we can.
- CWChris Williamson
Yeah.
- DLDaniel Lieberman
But let me just... Before we do, let me, let me just get to this, which is that, uh, pretty much any non-crap diet can help somebody lose weight. Uh, pre- um, and the hard part is to sustain it. And so you need to make a distinction between efficacy and effectiveness. So efficacy is basically how well a diet works when it... in the perfect world, right? When there's no cheating, and you eat exactly what you're told, and you can do it for a long time, and, and, you know, it's perfect. Effectiveness is how it works in the real world, and it turns out that low carb diets have this higher efficacy for weight loss than low fat diets. This is for weight loss. But their effectiveness, because people have a hard time sustaining them-
- CWChris Williamson
Mm-hmm
- DLDaniel Lieberman
... is only slightly larger.
- CWChris Williamson
Right.
- DLDaniel Lieberman
Uh, so-
- CWChris Williamson
If you could do it, you might perform very well, but being able to do it, the difficulty is somewhat harder-
- DLDaniel Lieberman
It's hard
- CWChris Williamson
... which means that it mitigates some of those gains.
- DLDaniel Lieberman
I mean, I tried it. I mean, I tried it. I tried, I tried-
- CWChris Williamson
I've tried every, I've tried every single one of these. By the way, I, I have done a much more bro science equivalent of what you did in the research for this book.
- DLDaniel Lieberman
Yeah.
- CWChris Williamson
I tried all of these.
- DLDaniel Lieberman
Yeah, I mean, I tried the... I tried an Atkins diet, and it was hard because I, I had intense carbohydrate cravings, and I'm a runner, and, you know, it's hard to be a runner and not eat carbs.
- CWChris Williamson
The hunger is rough.
- DLDaniel Lieberman
Yeah. I mean, I just [chuckles] just... I didn't like it that much. Um, but I didn't like a lot of the diets that much. But let's, let's go into the biology behind low carb diets, 'cause, 'cause it, it's really interesting. So when you eat food, um, your, um... Some of that food, of course, is carbohydrate. And carbohydrates, your body breaks down into, uh, some of it into glucose, which is the bas- one of the two major kinds of sugar. There's fructose and glucose. Fructose is what you get from fruit. It's kind of... It's, it's sweeter. Glucose is the kind of more starchy, you know, less sweet form of sugar, and so th- and that go, goes straight into your bloodstream. Glucose is... Your body can only handle a very, very small range of glucose, 'cause too much is toxic. In fact, I think average human being has about a teaspoon and a half of glucose in their entire bloodstream, and if it goes above that, you're in trouble. You become hyperglycemic, and you can go into... You can have serious medical problems. So our body is super sensitive to glucose. So when you eat a meal, and it has glucose in it, your, your blood sugar level goes up, and because the body has to maintain a very tight range of glucose, you- your pancreas releases a hormone called insulin.
- CWChris Williamson
Mm-hmm.
- DLDaniel Lieberman
And insulin is... You're basically, it's your growth hormone. It's the hormone that causes you to store stuff. It... So it-- Insulin causes your, your, your cells to take up that glucose so the levels go down. Now, s- uh, insulin also tells your cells to hold on to energy, so, so to prevent [chuckles] your cells from releasing, releasing fat, 'cause you, you store that energy as fat. Your cells turn the glucose into fat. [coughs] Excuse me. So when you are on a low carb diet, you keep your insulin levels low, and that means that you're l- storing less, and also you're not holding on to that fat, and that helps you... And, and that can... And so, so the biology is pretty simple, and I guess, uh, pretty clear, though it gets more complicated because there's another hormone called glucagon, which makes it more complicated. Um, physical activity affects things. There's, you know, there's... Nothing is ever simple, and, and, and the carbohydrate insum- ins- insulin model is, is, is no exception. So, so there's real basic logic behind the, the, the, the carbohydrate insulin model. Uh, the problem is that when people go on these low carb diets, they're hard to sustain, and a lot of people, um, uh, can't maintain them for that long, and their carbohydrate levels creep up-
- 51:57 – 54:00
Why Dieting is Simpler Than You Think
- DLDaniel Lieberman
there are whole cobs of truth to all of these diets. And why do we have to pick between low fat versus low carb versus low calorie? I haven't even talked about low calorie, right? Why do we have to pick? You can actually take the best of all, of all of them, right?
- CWChris Williamson
Yeah.
- DLDaniel Lieberman
So you can take the best of the low carb diet by rem- by eliminating or removing or not eating too much of refined carbs that raise your insulin levels. You can take the best of the low fat diet by not eating too much highly caloric saturated fat, which does to, according to a lot of studies, um, uh, either increases your risk of cardiovascular disease or doesn't lower your risk of cardiovascular disease. We can talk about that later on. So polyunsaturated and monounsaturated fats are, are risk lowering fats. And also, you know, calories do matter. How many calories you eat do, do matter.
- CWChris Williamson
We, we need to talk-
- DLDaniel Lieberman
And, and so, so you don't... You know, not eating too much is also helpful. So why not combine-
- CWChris Williamson
Mm
- DLDaniel Lieberman
... the best of all these various kinds of diets without, without going down the, the kind of, uh-
- CWChris Williamson
But as soon as you combine the best of all of those kinds of diets, you now have a new diet.
- DLDaniel Lieberman
No, you have the Medi... You know what you have? You have the Mediterranean diet.
- CWChris Williamson
That's the diet. That is a new diet.
- DLDaniel Lieberman
Or, or, or, or you have essentially any traditional farming diet.
- CWChris Williamson
Okay, okay.
- DLDaniel Lieberman
Uh, so, uh, so I would say that a, a, a, a traditional Asian diet, a traditional African diet, a traditional Mesoamerican diet, a traditional Mediterranean diet all share the same basic characteristics that we just talked about, a lack of highly refined carbohydrates that raise your insulin levels-
- CWChris Williamson
Mm
- DLDaniel Lieberman
... not too much saturated fat, not too much food, not too... You know, a, a, a diversity of foods, a, a mixture of, of whole grain, uh, cereals combined with legumes that give you complementary protein.
- CWChris Williamson
Mm.
- DLDaniel Lieberman
People have been eating these for thousands and thousands of years. Now, are they optimal diets that are gonna guarantee you to live to be 100? No. But are these diets that have, over the ti- course of time, plus in recent studies, been shown to be generally healthy and prevent weight gain? The answer is yes.
- CWChris Williamson
Okay.
- DLDaniel Lieberman
So it's, so in a way, it's not that complicated.
- CWChris Williamson
That we've started to simplify.
- 54:00 – 1:02:35
Is Calorie Restriction Worth It?
- CWChris Williamson
What about calorie restriction? I've been told that it's the only reliable intervention that actually works for extending lifespan. How import-
- DLDaniel Lieberman
If you're a mouse.
- CWChris Williamson
Uh, are you saying that-
- DLDaniel Lieberman
[laughs]
- CWChris Williamson
Are you saying that the rodent studies don't come across into humans when it comes to calorie restriction or lifespan?
- DLDaniel Lieberman
No, there, there's no evidence yet in humans. In fact, not even in primates. So do you know, there was, there was a big study that was done in, um, in, um, Wis- Wisconsin where they took a whole bunch of macaques, right? And they gave, uh, one group of macaques a calorie restricted diet and another group of macaques... And this was a 20-year-long study. Imagine how much time it took and money-
- CWChris Williamson
Two decades of calorie restriction if you were in the wrong group of macaques.
- DLDaniel Lieberman
[laughs] And guess what? The group of macaques that were in the calorie restriction diet were way healthier than the ones that were not on the calorie... And so, so there were these papers published saying, "Ta-da, calorie restriction works in primates, which means it probably works in humans." But guess what? When people looked at the data, the non-calorie restricted macaques were basically being fed a crap food diet. They were getting lots of sugary foods. They were g- uh, getting obese. They were... You know, they were not healthy, normal macaque diets. They were fed an ad libitum crap diet. So the NIH, at vast expense, I mean, we're talking millions of Taxpayer dollars redid the experiment where this-
- CWChris Williamson
Another two decades
- DLDaniel Lieberman
For another two decades [laughs]
- CWChris Williamson
Fuck me. If you're the guy, if you're the guy that fed those macaques fries for two decades, you really should be out of a job
- DLDaniel Lieberman
It's very shameful. But anyway, so the NIH redid the experiment f- and, and this time they had them on the same monkey chow diet. So, you know-
- CWChris Williamson
Just chopped one in half away
- DLDaniel Lieberman
... yeah. And, and one had a third, 30% less food than the other
- CWChris Williamson
Yep, yeah
- DLDaniel Lieberman
And guess what? No difference. Zilch. In terms of health and longevity.
- CWChris Williamson
Why do you think it does show up in mice?
- DLDaniel Lieberman
Because mice have totally different l- uh, life histories. So life history is the series of stages that you go through, how you use energy to grow up, reproduce, and, and whatever. And, and you know, a typical mouse is ready to reproduce after three months, you know, and it has series of babies, et cetera, et cetera. Mice have totally different metabolisms and different growth trajectories and diff- different d- uh, microbiomes and different, you know, than, than humans. So, so yes, it is true that, uh, uh, for some species, for some, um, mouse lines, but not all, caloric restriction has been shown to improve their lifespan, but not all of them, by the way. Um, certainly true for yeast, certainly true for fruit flies, but the evidence for humans is so far mixed. Now, I should also say that it's not based totally on hooey, right? I mean, there are reasons to believe that caloric restriction can be very beneficial. And, and again, I try to explain the biology kind of carefully in the book. But one of them is that it causes what's called metabolic switching. So after a meal, our... your body's got all this nutrients and energy, et cetera, it wants to use it, and so you go into growth mode. And there's a famous gene called mTOR, you've probably heard of it, the mammalian target of rapamycin. And mTOR is like a, uh, it's like a, it's like an on gene, right? It's like a growth gene. It causes you to grow muscle and grow this and grow that and produce proteins and do all kinds of good stuff. Um, but the consequence of that is that it also causes damage, right? The, when you get your muscles produce, producing more proteins, you produce what's called reactive oxygen species that can cause damage. You, you get, you get, you get, um, you get, um, you know, misfolded proteins. You get all these problems, right? But you, but, but so there's another pathway that's turned on by another big gene called AMPK. Um, and AMPK is like your repair gene. And what happens when you go through intermit- intermittent fasting or calorie restriction is that you turn down or turn off the mTOR and turn up the AMPK.
- CWChris Williamson
Mm-hmm
- DLDaniel Lieberman
So you're turning off growth and you're turning up repair, and that's obviously good, right? But you can't repair all the time. Sometimes you have to grow. And so this kind of metabolic switching between the two is really good. The problem, I think, is that a lot of Americans and Europeans and, you know, people in high income countries, we're constantly in growth mode. I mean, how often are we hungry anymore, right? There's, there's candy-
- CWChris Williamson
Permanently grazing
- DLDaniel Lieberman
We're permanently grazing. There's, there's, there's... You know, in my building, you know, if anybody gets hungry for just, you know, you just go down one flight of stairs and there's these, you know, snack machines, and y- you never have to be hungry. So that means that some people are just constantly in this on mode, and they're not turning on, on, on their repair mode. Um, uh, but we obviously evolved to have these mixture of repair and growth. And so, so there is... And of course, when you go into intermittent fasting or, you know, calorie restriction, you are turning on that repair mode, and that's good. So there... So I'm not saying that it isn't necessarily beneficial or that it might not lead to increased longevity. It's just that the evidence so far doesn't exist. Uh, so you're, you're taking another leap of faith. Um, uh, I, I'm sure it's, it's generally healthy.
- CWChris Williamson
Mm
- DLDaniel Lieberman
Whether it'll help you live to be 100, anybody who tells you that's the case is, is, is going beyond the evidence. It might, it might be... It's not a bad strategy, but it's not... There, there's no strong evidence to that effect. And-
- CWChris Williamson
That's crazy. I didn't know that there was no strong evidence. I mean, look, the hormetic stressor, uh, uh, um-
- DLDaniel Lieberman
Well, that's how people make money. You know? [laughs] If they told you, if they told you like what I just told you, that, you know, "This is how it might work, but we're not really sure"-
- CWChris Williamson
It's highly unsexy
- DLDaniel Lieberman
... you're not gonna buy, you're not gonna buy the product. You're not g-
- CWChris Williamson
Many, many of your arguments are highly unsexy, is a way. Like unmarketable, like what's-
- DLDaniel Lieberman
They're completely unsexy.
- 1:02:35 – 1:06:15
What’s Special About Intermittent Fasting?
- CWChris Williamson
simplicity. What is interesting to me around the sort of calorie restriction thing is the super magical sauce that's inside of the intermittent fasting. It's the 16/8, right?
- DLDaniel Lieberman
5/2.
- CWChris Williamson
Yeah, yeah, yeah. It's, it's-
- DLDaniel Lieberman
Or there's the, there's the, um, what's it called? The, the, the, the warrior diet. [laughs]
- CWChris Williamson
Is that, is that OMAD?
- DLDaniel Lieberman
I can't remember. The warrior diet is you eat like, like only once a day.
- CWChris Williamson
Yeah, OMAD. One, one meal a day.
- DLDaniel Lieberman
Yeah. [laughs]
- CWChris Williamson
Um, is there something special about intermittent fasting?
- DLDaniel Lieberman
Well, again, intermittent fasting moves your body in and out of what's, we call positive and negative energy balance, therefore turning on and off mTOR and AMPK. It's calling metabolic switching.
- CWChris Williamson
But you could imagine a-
- DLDaniel Lieberman
But there's no one way to do it
- CWChris Williamson
... you could imagine a world in which you did calorie restriction. Let's say maintenance for me is 2,400. I could calorie restrict even down to like a significant amount, like 1,800 or 1,500 or something. But I could do that by consuming, uh, 100 calories every hour for each wake, waking hour that I was awake. This would be kind of a highly inefficient diet to have.
- DLDaniel Lieberman
[laughs]
- CWChris Williamson
But you understand what I mean, right? There's a difference between grazing your way to calorie restriction or fasting your way to calorie restriction. If you were to take... Have you seen any evidence that if you were to take two populations, one of whom was doing OMAD and another of whom was grazing to a similar kind of calorie restriction, that they would have different outcomes?
- DLDaniel Lieberman
In terms of weight or in terms of inflammation or whatever? So, so, uh, uh, if tho- if those studies exist, I don't know them 'cause I'm ... They're, they're-
- CWChris Williamson
Be a cool study to do
- DLDaniel Lieberman
... well, I don't... Uh, yeah, maybe, but-
- CWChris Williamson
Don't maybe my suggestion.
- DLDaniel Lieberman
Uh, no, no [laughs]
- CWChris Williamson
That's a cool study, okay?
- DLDaniel Lieberman
Yeah, but, well, I'm ju- I'm ju-
- CWChris Williamson
Says the guy that's not in your industry at all
- DLDaniel Lieberman
... [laughs] I'm, I'm just thinking about the, the hypothesis that we're trying to test. So the, the, the mechanism by which intermittent fasting or low calorie, you know, calorie restriction is supposed to work is by, by putting the body into a negative energy balance. And as you say, there's two ways of doing it. One is to fast, or the other is to not eat very much. Certainly, there's a lot of data on not eating very much. Um, uh, that's just called a diet, right? And, and, um, and the problem with diets is that people get hungry, and they're really, really, really hard to maintain.
- CWChris Williamson
[laughs]
- DLDaniel Lieberman
And they're not very useful for most people because you're tired, you're exhausted, you're cranky, you're hangry, you're whatever, right? Intermittent fasting, one of the reasons people love intermittent fasting is that you just, you know, basically skip breakfast, for example, by one, one form of intermittent fasting. And so you can... It's much more tolerable. And plus, the other benefit of intermittent fasting, again, is that, is the metabolic switching, going from one to the other. 'Cause nobody in their right mind would think that c- being in a constant state of negative e- energy balance is a good thing, right? [laughs]
- CWChris Williamson
It's called starvation.
- DLDaniel Lieberman
It's called starvation, right? This is g- And, and here's another thing. In addition to the fact that there are trade-offs, every time you do one thing, you don't do something... Every, every food, every ti- diet, everything, though, there, there are benefits and there are costs. There's nothing... Find me one that doesn't have a trade-off, and I'll be, I'll be really interested. But I've yet to find one. But remember this also, that we are adapted not... We're not adapted to be healthy. We m- na- natural selection didn't put us on this earth to live to be 100. We evolved for one thing and one thing only, as far as natural selection is concerned, is, that's to have babies. Um, so we evolved to ha- to maximize our reproductive success, not to be long-lived and healthy. And so w- uh, so a lot of the adaptations that we have are n- are, are, are there not to improve our health. They're to improve our reproductive success. And, and that makes things complicated.
- CWChris Williamson
Mm.
- DLDaniel Lieberman
And, and that adds to the trade-offs.
- 1:06:15 – 1:11:13
Breaking Down the Paleo Diet
- CWChris Williamson
What about the sort of world of the modern paleo movement? Because what it sounds like, y- paleo is in one of the titles that you have for the world that you come from, uh, looking at a more ancestrally aligned natural without falling into a naturalistic fallacy type diet. You could assume, hey, well, if we just eat like hunter-gatherers did, and the paleo movement kind of promised this from a dietary perspective, but is it right to say that there is an ancestral diet that we can recreate? Has the paleo movement got it right?
- DLDaniel Lieberman
Uh, I wish they had, but they, again, um, [laughs] I know I'm gonna sound like a broken record, but they got some things right, and they got some things wrong. So it is true that, uh, some aspects of the paleo diet make a lot of sense, right? You know, don't eat a lot of sugar, don't eat a lot of saturated fat. That's the original paleo diet, is don't eat a lot of saturated fat. Um, there's some paleo dieters dis- dispute that. Um, but the paleo diet also says you should never eat legumes, and you should never eat grains, and you should never eat dairy. Um, and the, and their, the argument for that is that our ancestors didn't eat legumes and grains, um, and then we only had dairy, uh, until we stopped nursing, and then, you know, that for, after we stopped drinking our mother's breast milk, that was it Um, well, several problems. First is [laughs] it's not true that hunter-gatherers don't eat legumes and grains. Uh, it's absolutely just, just absolutely-
- CWChris Williamson
Don't or didn't?
- DLDaniel Lieberman
D- don't and didn't, both.
- CWChris Williamson
Both.
- DLDaniel Lieberman
We have paleontological evidence. We have Neanderthals with grain st- starch thing on their teeth. We have-
- CWChris Williamson
Oh, that sounds like reliable evidence.
- DLDaniel Lieberman
We have [laughs] very reliable... You know, the, we have this kind of cartoon character of the Neanderthals eating, like, all meat like, you know, Inuit in, like, in Greenland. But you know, you know, 125,000 years ago, there were hippos frolicking in the Thames when the Neanderthals were hanging out in southern England. The Neanderthals were not living in Arctic conditions all the time. There were, there were times when there was plenty of plants available, and they were [laughs] eating plenty of plants. We have archeological evidence for that. In addition, for example, hunter-gatherers in the Kalahari, the second most consumed food are is a kind of bean. It's called the morama bean. It's their number two food. So don't tell me they don't eat legumes. They do. Um, um, hunter-ga- ... We evolved to eat almost everything, and so actually, we did a study on this a few years ago. It was actually during COVID when, you know, it was lockdown and, and I had a undergraduate who was gonna do a experimental project in the lab that involved, you know, putting people on treadmills and that kind of stuff, and of course she couldn't do it 'cause the lab was closed. So we decided, uh, since she was stuck at home, to, uh, to go through the literature on all the high-quality data on hunter-gatherer diets from the tropics and just analyze the hell out of the data, and compare that to what the paleo diet prescribes. 'Cause the paleo diet says you should have, oh, I can't remember. It's, like, 35% protein and X percent carbohydrate and I ... I can't remember the exact formula.
- CWChris Williamson
Hmm.
- DLDaniel Lieberman
Uh, the, there are 12 hunter-gatherer groups for which we have really good data, uh, excellent data, where people actually measured carefully what they eat, and they're all over the place. Some of them are eating pretty much all plants, almost no, no animal food. Some are eating [laughs] tons of animal food. Everything in between. Hunter-ga- ... We evolved to eat anything. We are the world- animal kingdom's ultimate omnivores. We evolved through cooking and fermentation and various other techniques to, 'cause again, remember the f- equation of life is food in equals babies out, and that's all that natural selection cares about. You, if you, if you can eat it, and it can help you make babies, you should. So the idea that we evolved to eat some particular diet is just not true. We evolved to eat incredible diversity of diets, and remember that we didn't evolve to eat them to be healthy and to live to be 70, 80, 90, although hunter-gatherers do end up being relatively healthy.
- CWChris Williamson
Yeah.
- DLDaniel Lieberman
We evolved them to maximize our reproductive success. So the paleo diet is based on kind of a naturalistic fallacy, that if our ancestors ate it, it must be good. I m- by that imag- by that token, you know, we shouldn't, you know, if w- if we ... Shouldn't we, maybe we shouldn't, like, brush our teeth or sleep on mattresses or whatever, right? And, and it's also based on this idea that, uh, that, um, that, um, that, that, that, that these, you know, legumes and cereals are, are filled with these, quote-unquote, "antinutrients." So antinutrients are compounds that, like, bind to vitamins and minerals and, and prevent us from absorbing them.
- CWChris Williamson
Hmm.
- DLDaniel Lieberman
But guess what? If you cook your food, or you ferment [laughs] your food, you get rid of the antinutrients.
- CWChris Williamson
Hmm.
- DLDaniel Lieberman
Otherwise, you know, all, all those people in Japan who have the greatest longevity, you know, they'd be, they'd be dying of malnutrition. They're clearly not, right? P- uh, uh, um, uh, so there's, there's, again, there's a ... A lot of these diets are based on elimination. And, and, and they're based on, on stoking certain kinds of fears. Um, and, um, and, and, and that's problematic. So the paleo diet's not completely wrong, but it's not completely right. Sorry to ... Long answer to your simple question.
- 1:11:13 – 1:12:45
The Truth About Antinutrients
- CWChris Williamson
I'd never heard of antinutrients before, but I knew that people get worried about lectins and, and, and phytates and oxalates.
- DLDaniel Lieberman
Those are antinutrients.
- CWChris Williamson
What's the truth about the danger of lectins and oxalates and phytates?
- DLDaniel Lieberman
Well, if you ate raw beans, you'd be [laughs] in trouble, right? Because they're filled with these lectins, and they would ... You know, they can cause all kinds of prob- ... But guess what? If you cook your beans, you're just fine. Um, uh, so th- these are compounds that, um, that are, that we e- You can't ... That's why we can't eat raw beans and raw grains, 'cause of those, those, those compounds. But-
- CWChris Williamson
What do they do to us?
- DLDaniel Lieberman
They, they again, they bind to, to minerals and pr- and, and vitamins so that you can't absorb them in your gut, so you'd have malnutrition. You'd have vitamin-
- CWChris Williamson
You'd eat it-
- DLDaniel Lieberman
Yeah
- CWChris Williamson
... but you wouldn't absorb it.
- DLDaniel Lieberman
Correct. But obviously that's not the case, right? I mean, I know plenty of healthy vegetarians who are clearly not malnourished. [laughs] They're doing-
- CWChris Williamson
Despite eating lots of beans.
- DLDaniel Lieberman
Yeah, because they cook their beans. Paracelsus, remember Paracelsus, the famous alchemist from, chemist from s- from the 15th or 14th century? He famously said, "It's the dose that makes the poison." Right? And, and these, these compounds, by the time that you cook them and ferment them, they're in such harmless doses, there's absolutely no reason to be concerned.
- CWChris Williamson
Even the oxalate thing? I've heard even cooked spinach, spin- That's a concern for some people. You're ta- Come on.
- DLDaniel Lieberman
Sure.
- CWChris Williamson
What's going on?
- DLDaniel Lieberman
I mean, maybe for some people, but not for most of us.
- CWChris Williamson
Right. You're not ... These aren't ... Antinutrients aren't a concern as long as things are well-cooked, are you-
- DLDaniel Lieberman
I mean, I think there are some people with certain kidney issues that, that, that have problems with spinach, but for the rest of us, I think spinach is a delicious, healthy food.
- CWChris Williamson
Well,
- 1:12:45 – 1:15:48
Why the Raw Food Diet is So Hard
- CWChris Williamson
you've activated another trap card now, which is the raw food diet.
- DLDaniel Lieberman
[laughs]
- CWChris Williamson
You know?
- DLDaniel Lieberman
Oh, my God. I have to tell you, of all the diets I tried, by far the worst. It was-
- CWChris Williamson
What, what was-
- DLDaniel Lieberman
It was-
- CWChris Williamson
... a typical day for you eating the raw food diet?
- DLDaniel Lieberman
Oh. I mean, uh, we gave it up, uh, because it was so hard. I mean, I mean, look, I s- First of all, I was eating ... Because, look, cooking increases how much energy you get from food. It actually ... Cooking releases nutrients from food. So on a raw food diet, you have to eat ridiculous amounts of food just to, just to get enough food. I mean, I was just eating constantly. I was always hungry, and I spent huge amounts of time thinking about food, and-
- CWChris Williamson
What were you eating? What's a typical day?
- DLDaniel Lieberman
Oh, we were, like ... Well, I mean, it was h- it was, it was, it was difficult because so much of what we eat requires cooking. Humans evolved to cook. It's ... There are no ... The only people on the planet who don't cook are raw foodists in places like Berkeley and Cambridge and stuff like that, right? Um, y- and, and e- and they're, they [laughs] -
- CWChris Williamson
The most developed places in the world.
- DLDaniel Lieberman
Yeah.
- CWChris Williamson
Not the least developed places.
- DLDaniel Lieberman
You cannot possibly, uh, survive on a raw food diet without a really high-quality diet. And even then, it's difficult to thrive.
- CWChris Williamson
Right.
- DLDaniel Lieberman
Because, because cooking releases Energy. Cooking releases nutrients. You get more energy from cooked foods than from that good... So, uh, we were eating like, you know, zoodles, you know, zucchini noodles, and we were eating, you know, uh, smoothies, and we were eating, um, um, um, you know-
- CWChris Williamson
Fish? Did you eat any raw fish?
- DLDaniel Lieberman
I ate raw fish, absolutely. [laughs] I love, I love sushi, but you can't have it with the rice [laughs] 'cause the rice is cooked, right?
- CWChris Williamson
Right.
- DLDaniel Lieberman
So, um, um, it was really hard to, to... I mean, I was just constantly hungry, and my wife got depressed. Um, um, she, um, she-- I describe it in the book. She, um... after three days, uh, she disappeared and came back [laughs] looking really happy. She went out and got a bagel, and that was, that was it for her.
- CWChris Williamson
She broke containment.
- DLDaniel Lieberman
I, [laughs] I, I made it another day. I mean, um-
- CWChris Williamson
You lasted four days on the raw food diet.
- DLDaniel Lieberman
I lasted four days. It was, it was, it was, um, it was really hard, yeah. Uh, and look, uh, uh, it's based on the... again, it's a naturalistic fallacy that somehow, because, you know, you know, animals don't get these various diseases 'cause they eat raw food, that, that somehow it must be really good for us. But w- but we, our species, started cooking maybe a million years ago. Certainly by four hundred thousand years ago, cooking became extremely common among our ancestors to the point that it's changed our digestive systems and enabled us to have these big brains and big bodies-
- CWChris Williamson
Yeah
- DLDaniel Lieberman
... and high metabolisms that, that we cannot support without cooking.
- CWChris Williamson
How important was cooking to human development?
- DLDaniel Lieberman
Uh, crucial. I don't think we would be the species that we are without cooking. Uh, we would not... we wouldn't have our big brains. We wouldn't have the levels of body fat that we have. Cooking enabled us to have the kind of, uh, reproductive rate that we have. Cooking, cooking gave us more energy, and, you know, we are an energetically extravagant species [laughs] and, and, and cooking is one of those key elements. Food sharing is another. Meat was part of it as well.
- CWChris Williamson
Mm.
- DLDaniel Lieberman
Um, cooking is incredibly important part of the, of the human evolutionary story that ca- that made
- 1:15:48 – 1:19:38
What Cooking Really Does to Digestion
- DLDaniel Lieberman
us who we are.
- CWChris Williamson
What does cooking do to digestion?
- DLDaniel Lieberman
Cooking, cooking breaks down cell walls, most importantly, so that, you know, when you eat a cooked f- cooked f- like, if you eat cooked corn versus raw corn, and then you look in the toilet the next day, what, what do you see? [laughs] Right? I, I think I... that, that experiment's pretty easy to do. You, you digest a lot, a lot more, more, uh, more of your food when it's cooked, 'cause you break down the cell walls, you break down the, d- down the, down the... y- you release the nutrients. Cooking also makes food safer. So if you eat raw meat versus cooked meat, uh, which is more likely to make you sick? And, and when you're sick, you have to s- if, if you survive it, you just have to spend a huge amount of energy fighting that, right? And-
- CWChris Williamson
Speaking to somebody that got salmonella in Rwanda, yes.
- DLDaniel Lieberman
[laughs] Oh, dear. I'm so sorry.
- CWChris Williamson
It's okay. I survived. I survived. But I did get a call from, uh, the UK, um, it's like food and safety, uh, uh, people that they go around and they... if, if you go to your GP. I felt horrible, obviously, and, uh, went in, did some stool sample thing, and I got a call from environmental health before my doctor called me to tell me what had happened. And they said, "Mr. Williamson, uh, we understand that you were part of a salmonella outbreak." I'm like, "Okay. Well, thank you for telling me what's wrong with me."
- DLDaniel Lieberman
[laughs]
- CWChris Williamson
Uh, but they wanted to work out where I'd been. They wanted to know, "Hey, what was the restaurant? What restaurants have you been?" I'm like, "Unless you're gonna fly out to Rwanda, this is not in your purview, I don't think." But that took a long time to recover from. Like, fully, fully recover-
- DLDaniel Lieberman
Yeah, salmon-
- CWChris Williamson
... digestion from. It is gnarly.
- DLDaniel Lieberman
Sal- I've had salmonella once. It's tough. Yeah, it's really hard. I got it at, I got it at the, at the, um, at the, at the, um, cafeteria at my medical school in, in, in Eldoret, Kenya. [laughs] My entire team got, got sick from the t-
- CWChris Williamson
Oh, well, at least it was something that you could bond over.
- DLDaniel Lieberman
[laughs] Bonding is one word for that. [laughs]
- CWChris Williamson
Yeah. Yeah, yeah. You can be in the stalls next to each other all, all hating your life. Most people have no idea where their testosterone levels sit. But what if I told you there was a solution? Something that identifies low T faster than a high school bully, and it won't cost you all your lunch money. That's where Function comes in. Gives you access to over a hundred and sixty lab tests, including a deep dive into your full hormone panel. Every result is reviewed by clinicians. Anything out of range is flagged, and you get clear explanations with a personalized protocol with actionable next steps. So if something's off, you know exactly what to do about it. Whether you just need to go to the gym more, or you need to play Creed louder in your car, Function will tell you exactly where your testosterone and everything else stands. Normally, this level of testing would usually cost thousands, but with Function, it's three hundred and sixty-five dollars a year. That's one dollar a day to stop guessing with your health and start knowing. And right now, you can get twenty-five dollars off, bringing it down to three hundred and forty bucks. So get the exact same blood panels that I do and save twenty-five dollars by going to the link in the description below or heading to functionhealth.com/modernwisdom using the code modernwisdom at checkout. I got a question. Have we ever seen any other animals using temperature to moderate food in any way? Does anything leave something out, put something away? Is there any kind of, like, mediation with regards to temperature for-
- DLDaniel Lieberman
Not on a regular basis. Uh, uh, but it's interesting, though. If you... There are these fun experiments where they give chimpanzees, give them the opportunity to choose between cooked food and raw food, and even though chimpanzees don't cook their food, they always... they, not always, they usually prefer the cooked food. And it has been observed that s- that sometimes, like after a brush fire, the chimpanzees will eat the, the burnt stuff.
- CWChris Williamson
Oh, a barbecue.
- DLDaniel Lieberman
Yeah, it's like a natural barbecue. But they're, they're taking advantage of a natural brush fire. They're not, they're not cooking it themselves. If there are animals that, that, uh, you know, no, that, that, I, that I don't know of.
- CWChris Williamson
Was, would you-
- DLDaniel Lieberman
We're,
- 1:19:38 – 1:24:58
Did Farming Make Humans Healthier?
- DLDaniel Lieberman
we're unique
- CWChris Williamson
... would you say that farming was a healthy human development?
- DLDaniel Lieberman
Oh, my God. That's an interesting topic. I mean, it's [laughs] how many hours you have?
- CWChris Williamson
I'm just throwing grenades at you here to-
- DLDaniel Lieberman
[laughs] Remember the equation of life, right? Food in equals babies out.
- CWChris Williamson
Yep.
- DLDaniel Lieberman
So some people say that farming was the biggest mistake that humans ever made, um, because once people ate farming diets, they had less nutritional diversity, and they ate more grains and cereals and blah di, blah di, blah. And if you look in the archeological record, once farming starts, people's health declined. But the reason for most of those declines in health was because of infectious disease, because we started several things. First is we started living with animals, right? So we had-
- CWChris Williamson
Right
- DLDaniel Lieberman
... we living with our sheep and our cows and whatever, and we started getting diseases from those animals. So, so infectious-
- CWChris Williamson
As opposed to only having the animals with us that we could kind of kill or use to maybe pack, like-
- DLDaniel Lieberman
Yeah, we don't
- CWChris Williamson
... carry packs and shit.
- DLDaniel Lieberman
Yeah, we don't... Yeah, exactly. We don't, we didn't get many animal, animal diseases until-
- CWChris Williamson
Just this exposure of human to animal was so low.
- DLDaniel Lieberman
Exactly. So that's one. The other is that with farming, you produce way more food. I mean, hunter-gatherers struggle to get, you know, a few thousand calories a day, but farmers can, even, you know, neolithic kind of farmers, you know, with simple non, without machines and all that-
- CWChris Williamson
Even the shit farmer can get more calories than he needs
- DLDaniel Lieberman
... way more, right? They, they have much larger families. So, and with farming, not only did populations start to increase, but we also became sedentary and started living permanently in villages. So now you have higher population densities, higher populations living with animals. Now you're surrounded by your own shit, 'cause you don't have, you don't have sani- you don't have toilets, and you don't have, you don't have, um, uh, sewers and all that kind of stuff. And so now you get the perfect, uh, mix of, of factors to increase infectious disease and infectious disease transmission.
- CWChris Williamson
Mm.
- DLDaniel Lieberman
And so with the advent of farming, you had more people, but you also had a lot more disease. And so, um, so on the one hand, farming was great from an evolutionary perspective because we had more babies. I mean, the population of the world by the end of the farming era was up, up to about a billion people from probably about, you know, just a few million from before farming was invented, which is only what? About 600 generations ago. So in six, like six, 590 generations, the world went, got up to about a, from about a few million to a billion people.
- CWChris Williamson
Mm.
- DLDaniel Lieberman
So from that perspective, from a natural selection perspective, farming was a great idea [laughs] . But from-
- CWChris Williamson
Scale, goods, individual
- DLDaniel Lieberman
... but from the, from, from indi- from disease and misery, it was terrible. Also, with farming you get famines, right? If you're a hunter-gatherer and, and the, the, the weather is bad and you have a, you know, a drought or whatever, you just move, right? You, you, you're in enormous territories at extremely low population density. There's a lot of variation. So you go to where the food is. Now, it doesn't mean it's easy or you're necessarily gonna f- you know, you know, live in the lap of luxury. But if you're a farmer and you're living in a village and you can't go anywhere else, 'cause the next folks over are gonna kill you, and you, you have a drought, or say two years of drought and famine, y- you die, right? So, so farmers are much more vulnerable to famine and, and disease. Also with farming, you also have the rise of complex civilizations and armies and, and you know, the, you know, Napoleon's gonna come and, you know, burn your fields and, you know... I mean, so you have more of this kind of organized violence. It's not that hunter-gatherers don't kill each other, they do, but with farming you have, you have, and civilization, you begin to get more, uh, large scale w- warfare, which of course who suffers? It's the peasants. So farming brought a lot of misery and, and, and, and problems, although it did provide more food and more energy. So how's that for a-
- CWChris Williamson
Yet another mixed bag
- DLDaniel Lieberman
... not, uh, I'm sorry. It's-
- CWChris Williamson
I mean, like, it's just, it's so-
- DLDaniel Lieberman
I'm sorry, I'm an academic [laughs] .
- CWChris Williamson
Not at all. No, I, I think it's so, it's so wonderful, like the, the understanding the fifth order effects of something like that. What happens downstream I think is so cool.
- DLDaniel Lieberman
But if I could say something more about farming diets. So a lot of people mistake farming diets with modern diets, because when farmers were eating their grains and cereal, like think, think of a typical, like let's go back to the Mediterranean diet. Think a typical farmer from somewhere along the Mediterranean. They're growing barley or wheat, and they're having their lentils and their whatever, and their, you know, their, their, their, and their chickpeas and whatever. They're having their legume and their cereal, et cetera. Uh, when they're... And they're making bread, but they're, it's gonna be sourdough, whole grain, whole wheat, you know, sourdough bread with lentils. These are healthy diets in the general. They're not, these are not insulin spiking diets. Um, these are, these are effective diets. Um, and it wasn't until the late 19th century, actually it was in Hungary that, that, uh, in the Industrial Revolution that we figured out how to mill flour to get rid of the, the, the germ and the sperm, and then now all of a sudden we, when we think of like high cereal diets, we think of white flour, not brown flour, and that's a very different thing. I mean, there's actually a fair amount of nutrition in whole grains. Um, they're not, they're not the kind of poison that some people think they are. They're not... A- and especially when you combine them with legumes. So, so I think people have a f- kind of a funny conception of what a traditional farming diet is. It's been a, kind of a bit warped by modern, by modern, um, uh, cereal diets.
- 1:24:58 – 1:27:51
What’s the Real Story With Gluten?
- CWChris Williamson
What's going on with modern gluten intolerances?
- DLDaniel Lieberman
It's gone sky high. I mean, s- but so have peanut allergies and, I mean, the- we have all these autoimmune diseases where our immune systems have start, essentially erupt, uh, when we eat certain foods, and, and, and gluten, which is a protein in, in, in, in, in, in wheat, uh, is one of them. Um, but I would l- uh, and, and-
- CWChris Williamson
What do you think's going on with gluten?
- DLDaniel Lieberman
I think it's, um, if I had to, I, I... Have you heard of the hygiene hypothesis?
- CWChris Williamson
Yes. Yes. Where if you live in a house that's got a dishwasher, there's an increased chance of asthma, or if you live in a house that, uh... Is that as you make-
- DLDaniel Lieberman
That's, that's, that's a, that's a, that's, that's part of it. Yeah. So the hygiene hypothesis is this idea that we have these, we have immune systems that e- evolved to be very active, right? The world was full of germs and worms basically until, until, until modern sanitation. Uh, but you and I still have the same immune system that our great-great-great-grandparents had with the same kinds of cells and all that waiting, waiting to defend us against all the, all the, all the pathogens out there. Now we have dishwashers and we have bleach and we have-
- CWChris Williamson
Mm
- DLDaniel Lieberman
You know, we clean everything, right? And, and the result is that we have much less ex- we have fewer... I mean, how many worms have you had to deal with recently in your, in your food? Probably very few.
- CWChris Williamson
Yes.
- DLDaniel Lieberman
But until recently, and in many parts of the world, everybody was dealing with worms
- CWChris Williamson
You're saying that worms are an important, uh, hormetic stressor for the immune system.
- DLDaniel Lieberman
[laughs] They are.
- CWChris Williamson
Yeah.
- DLDaniel Lieberman
So, but you still have the same immune system, and now your immune system is, is still waiting to do its job. And the analogy-
- CWChris Williamson
It becomes hypersensitized.
- DLDaniel Lieberman
Well, it's not that... It could be hypersensitized or the, or the other analogy I use is, is, is it's like bored teenagers. Like, you know, they, they, you're, they have all these cells waiting around to do stuff, and there's nothing for them to do, and they're more likely to get into trouble because they now are more likely to attack self versus non-self, 'cause there's no non-self to attack.
- CWChris Williamson
Have you seen the data around children that grow up in houses that have got dogs in?
- DLDaniel Lieberman
Yeah, exactly, and they're much less likely to get autoimmune diseases. Uh-
- CWChris Williamson
Yeah. Any, any excuse to make dogs great again.
- DLDaniel Lieberman
But there's another factor, too. So, so one po- so that's one possibility, which is all the, all the, all the f- all the sterile environments that we're in. But another important factor could be, uh, antibiotics. I mean, we now have so many antibiotics that we are constantly taking and, and it's even, even if you don't take them, it's in your food because the antibiotics are given to animals. We are in a, in a antibiotic zone.
- CWChris Williamson
Milieu.
- DLDaniel Lieberman
Milieu. Thank you.
- CWChris Williamson
Mm-hmm.
- DLDaniel Lieberman
That's a much better word.
- CWChris Williamson
Mm-hmm. [laughs]
- DLDaniel Lieberman
And, and of course, those antibiotics are affecting our gut microbiome in all kinds of ways, and they're breaking down the mucus barriers, they're affecting bile, they're affecting all kinds of aspects in ways that we do not understand. And I think, I think there are l- there's a, there's a lot of people trying to study how tho- those antibiotics may also predispose us to, to having things like celiac.
- 1:27:51 – 1:32:16
Why Are So Many People Overweight?
- CWChris Williamson
So farming, mixed bag. Probably good overall for having more humans on the planet-
- DLDaniel Lieberman
Well, we wouldn't be here
- CWChris Williamson
... but for individual humans-
- DLDaniel Lieberman
We wouldn't be here if it weren't for farming
- CWChris Williamson
... cooking, same thing.
- DLDaniel Lieberman
[laughs]
- CWChris Williamson
I'm, I'm interested. Over time, typically things get better. Obesity is now a bigger global health issue than malnutrition. How come so many people are overweight?
- DLDaniel Lieberman
Well, there's no one answer. [laughs] Um, but if there's any one dominant factor, it's obviously processed food. I mean, I, I think you'd be hard-pressed not to... I mean, we are surrounded by... You know, you walk into a supermarket, and you are just surrounded by f- foods that are, uh, engineered for us to b- they'd be hyper-palatable, that, um, are loaded with, with, with sugar and fat and they're... and they, you know, hitting our bliss point, uh, so that we keep eating more and more and more and more. Um, and, um, um, and you add, and you add to that physical inactivity, although exercise is not the world's best... is not that great for losing weight. It is extremely important for preventing weight gain. Um, and then, um, and then you add antibiotics and you add various other factors and, and of course, some people have genetic proclivity, although that doesn't explain the, the recent rise. Uh, yeah, we are, we are s- we, we're, we are surrounded by f- food that makes us, um, makes us gain weight. And the, then the, then the difficult thing is that once, because of natural selection, w- we have this... We never evolved to lose weight. So we have these adaptations to hold onto fat 'cause we are, we never evolved to, to lose it.
- CWChris Williamson
Yeah, once you, once you create fat cells, you can't get rid of the fat cells. They only empty themselves. Is that correct?
- DLDaniel Lieberman
That's correct, for the most part. Yeah, the fat cells swell, and so what you're doing is reducing, but each cell has its own little kind of, you know, metabolic powerhouse, and it's producing hormones-
- CWChris Williamson
But if you, if the fat cells get sufficiently big, then they split, and you now have two fat cells, which means that getting fat in future becomes easier. When I first learned this... I'm not off with the science, right? Like this is-
- DLDaniel Lieberman
No, you're, you're not off. And furthermore, when you have more fat cells, remember we talked about the carbohydrate insulin model.
- CWChris Williamson
Yep.
- DLDaniel Lieberman
When you have more fat cells, those fat cells are-
- CWChris Williamson
Signaling
- DLDaniel Lieberman
... sucking up all that stuff. So you eat the same food, but now your f- body thinks you're, you're, you're, you're starving-
- CWChris Williamson
Yep
- DLDaniel Lieberman
... because you've sucked up all that glucose. You become hypoglycemic, so gaining weight actually makes you eat more.
- CWChris Williamson
Yeah. I mean, it blows-
- DLDaniel Lieberman
[laughs]
- CWChris Williamson
... this, this, learning this when I... Well, this was in uni when I was thinking about bodybuilding and wanting to be, you know, lean and jacked and stuff, and, uh, hearing that if you get sufficiently fat, fat cells grow and grow and grow, and then when they grow big enough, they split into two. And then maybe you lose fat. Maybe you're going through the, the classic sort of bulk cut, uh, seesaw. But when you lose fat, those two now, what used to be one, two fat cells, they shrink down and they become smaller or more empty or whatever, but there's still two.
- DLDaniel Lieberman
And, and they're also, they're also dec- they're producing less of a hormone called leptin, which is now telling your brain, "Shit, we're losing energy. You need to eat more to replace us." So, so it's this called, we called it the leptinostat. So the fat cells, when you lose fat, your, your, your... the fat cells send a signal to your body to eat more. So, so, so it's-
- CWChris Williamson
Becoming fat at one point in your life makes not being fat for the rest of your life harder.
- DLDaniel Lieberman
Correct. Yeah, so that's the problem. So if we are going to tackle this problem, A, we need to help people figure, lose weight, but B, we need to spend more energy and more effort to help prevent people from gaining weight in the first place. And one of the scariest statistics I know is the percentage of young people who are having, who are overweight or obese. It, tho- those numbers are going up and up and up and up.
- CWChris Williamson
What, what... How many young people are overweight?
- DLDaniel Lieberman
I think in the United States, something like 30% of, of, uh, of American teenagers, um, are now classified, or 25% are classified as, as being obese. Yeah. And that's a really scary number because those kids, for the rest of their lives, are gonna be fighting their weight.
- CWChris Williamson
Yep.
- DLDaniel Lieberman
And, and, and of course, now we have GLP-1s, which we haven't sort of talked about, which, which may be very helpful for them.
- CWChris Williamson
Mm.
- DLDaniel Lieberman
But, but that's, that's not the, necessarily gonna be the magic bullet either. Um-
- 1:32:16 – 1:38:41
Why We Crave Balanced Flavours
- CWChris Williamson
You mentioned before about, um, the particular combinations of, of flavors, flavors repres- representing, uh, macronutrients and w- what's inside of this, and, uh, some of the texture as well. I learned about aurification-
- DLDaniel Lieberman
Mm
- CWChris Williamson
... about the design of the texture of food-
- DLDaniel Lieberman
Yeah
- CWChris Williamson
... and how that's used to kind of bypass our, our usual levels of, of satiety and stuff. W- can you just explain to... Let's say that somebody didn't understand why particular combinations of flavors and textures are seductive and attractive to our system. What, what are they, and why is, why does that work in that, in that way? I've, I've seen these v- videos of hunter-gatherers eating cheesecake for the first time, and it looks like they've taken MDMA. Um...
- DLDaniel Lieberman
[laughs] Well, you know, we, we, um... I describe in, in, in, in, in the book actually, one, one... In the last day, we were with a, w- with a, a group of hunter-gatherers, and we, and we cooked for them, and I've never seen anybody [laughs] eat that much food as these, uh, these hunter-gatherers. I mean, they, they were just like, they were like complete non-paleo [laughs] diet nightmare as you can possibly imagine. Because humans are humans. We like, we like, we like sugar, we like fat, we like energy-rich foods.
- CWChris Williamson
But we don't just like sugar on its own, right? We don't just like fat on its own. It's this-
- DLDaniel Lieberman
You mix the two, yeah. So, so too much fat is greasy, right? Too much sugar is cloying. But it turns out that if you have a h- if you balance them, it turns our brains on like crazy. Like, can you name... Uh, here's a, here's a quiz for you. Can you name a f- natural food that's high in both sugar and fat that you can get without, you know, stores?
- CWChris Williamson
[inhales] Fuck. I was th- the, the, the fat thing is-
- DLDaniel Lieberman
There's only one. There's only one. There's only one.
- CWChris Williamson
It's not gonna be, it's not gonna be honey, 'cause that's just the sugar. It's not gonna be avocado, because that's just the fat. It's not gonna be some sort of mushroom. It's not gonna be a kind of berry, because again, that's gonna be too much in the sugar.
- DLDaniel Lieberman
I'll give you a hint. It's the first food you ever ate.
- CWChris Williamson
Milk?
- DLDaniel Lieberman
Yeah. [laughs]
- CWChris Williamson
Wow.
- DLDaniel Lieberman
Milk is rich in fat, and it's rich in sugars, right? And, and, uh, but after you wean, you know, that's it.
- CWChris Williamson
Game over.
- DLDaniel Lieberman
Unless, unless you have a [laughs] , a supermarket or, you know, f- food factory near you. Now we're able... And think about the foods we love. They combine fat and sugar. They... There's something Freudian about it, for sure, right?
- CWChris Williamson
Mm-hmm.
- DLDaniel Lieberman
Um, and you can h- And if you balance high amounts of fat and high amounts of sugar, that on their own wouldn't be pleasurable, together they balance each other out. Now add some salt, your brain is on fire. Um-
- CWChris Williamson
And then if you can do the texture-
- DLDaniel Lieberman
T- texture
- CWChris Williamson
... development, if you can get fluffy with crunchy, again, the-
- DLDaniel Lieberman
Oh, hot and cold. I mean, uh, think about a McDonald's Big Mac. I describe it in the book, right? I actually, uh, you know... Uh, uh, a Big Mac has, I think, every flavor pretty much, except for spicy, that you can possibly think of. It's got, it's got hot and cold, it's got crunchy and smooth, it's got sweet, it's got salty, it's got everything. There's a reason that people love that stuff, right? It lights everything up, right? Um, Doritos. Doritos have more than... Go, go, go buy [laughs] go get a package of Doritos. Don't necessarily eat them. But there are 30 ingredients in Doritos-
- CWChris Williamson
Oh
- DLDaniel Lieberman
... uh, uh, the last time I counted, and they have, you know, garlic, and I mean, there's all these different flavors, but they're all balanced, so your brain doesn't think any one is too high. So there's a, there's a book by, by a guy named Michael Moss called Salt, Sugar, Fat, which is really worth reading, where he's an investigative journalist, um, and he, uh, studied and, you know, c- collected information on how the big food companies, you know, through serious testing... These are not accidental foods. These are carefully formulated foods to keep us reaching-
- CWChris Williamson
Precision engineers
- DLDaniel Lieberman
... keep us reaching for more. Another example, uh, I got from his book is Mar- is, uh, M&M's. You know why M&M's have all these different colors?
- CWChris Williamson
No.
- DLDaniel Lieberman
To turn our brains on, 'cause, you know, think, "Oh, I'll have a red one."
- 1:38:41 – 1:43:06
Food Labels Don’t Tell the Whole Story
- CWChris Williamson
Why are the calories on a label not the calories that you absorb?
- DLDaniel Lieberman
Oi, yoi, yoi. That's an interesting question. So because the calories on the label are kind of an idea... It's a formula. Actually, it's over 100 years old, this formula. Was created by, by a game- a guy named Wilbur Atwater, who, who, who, who analyzed more poop than you can imagine. But anyway, Wilbur Atwater, uh, was a professor at, in, um, in, uh, in Connecticut who, who, who came up with these, these... And what they do is that you take some food and you, you separate out the, the carbohydrates, the fats, and the protein, and then you use a formula, 4.1, uh, calories per gram of, of carb, um, uh, uh, for, um, um, uh, 4.1, uh, calories per gram of, of protein, and nine point something, you know, for, for the fat. And, and that's the number on your, on your f- canned food. But that's what, that's what's available to you and that an average person would get, but it's not actually what you... You're, because you're, you're, you're, you're not a, you're not a partici- You're not a, you're not a bomb calorimeter in Atwater's lab. You're a human being, right? And, and so for example, if you take a, uh, peanuts, right? And, and you measure the, the, the content of the energy in your peanuts, and now you grind those peanuts up into peanut butter, which by the way is the world's greatest food, you, you get way more energy, about 25% more energy than if you ate the peanuts whole. Because the food processing, even though it's the same stuff, the food processing gives you access to more of those nutrients.
- CWChris Williamson
Because you don't have to work as hard?
- DLDaniel Lieberman
That's right, 'cause you break the food down to tiny little particles, right?
- CWChris Williamson
Yeah.
- DLDaniel Lieberman
And, and your enzymes-
- CWChris Williamson
Surface area, yeah
- DLDaniel Lieberman
... Right, surface area to volume ratio, your enzymes can break that food down more. If you take a banana and you blend a banana, you get more energy from that banana than if you just eat the banana whole. People have done that experiment. Another example, one of my-
- CWChris Williamson
Imagine if you were to just swallow the banana as well without chewing it-
- DLDaniel Lieberman
[laughs]
- CWChris Williamson
... that, that would also help.
- DLDaniel Lieberman
[laughs] Good luck doing that. But, um-
- CWChris Williamson
Yeah. 70%
- DLDaniel Lieberman
... um, one of my favorite experiments, there's a guy named Steven Secor at the University of Alabama, who studies what's called diet-induced thermogenesis, you know, the energy it takes to break down food. 'Cause food takes energy to digest. It's a lot, actually. And he, he used boa constrictors, 'cause boa constrictors you can, you know, they can not eat for, like, weeks, and then you can give it a rat, and then you can measure how much energy the boa constrictor spends eating, digesting the rat. And he would give the boa constrictor a rat, and then he'd give the... He'd wait a few months and measure how much energy the boa constrictor spent. You could do that by just measuring how much the boa constrictor heats up.
- CWChris Williamson
Yep.
- DLDaniel Lieberman
That's... And then you wait a few months. Boa constrictor's very happy. You give it the same rat or the s- exactly the same size rat, but this time he grinds it up. [laughs] Same rat, same amount of calories.
- CWChris Williamson
Ground rat.
- DLDaniel Lieberman
Ground rat, and the boa constrictor slips right through its digestive system. It doesn't heat up at all, or much less so because the boa constrictor's getting way more energy from that rat.
- CWChris Williamson
Wow. Wow.
- DLDaniel Lieberman
So when we pulverize our food, we grind it up, et cetera, say, when you guys make a smoothie, for example, you're getting more energy from a smoothie than if you had the same amount of fruit whole.
- CWChris Williamson
Does that mean that people should or shouldn't eat smoothies?
- DLDaniel Lieberman
Well, if you're... Depends if you're trying to lose weight or not. I mean, if you, you know, if you... I mean, I like smoothies. Smoothies are great. I eat them all the time, but I'm not trying to lose weight.
- CWChris Williamson
Mm.
- DLDaniel Lieberman
But if I was on a diet, I would probably cut down on my smoothies.
- CWChris Williamson
I've heard that, uh, celery is net calorie negative.
- DLDaniel Lieberman
Yeah, I've heard that too, but I don't believe that. Uh, I'm, I'm sure you don't get a lot-
- CWChris Williamson
That the energy needed to digest the celery because of how rough and fibrous it is-
- DLDaniel Lieberman
Yeah
- CWChris Williamson
... is greater than the amount of calories.
- DLDaniel Lieberman
You know, fiber doesn't take a lot of energy to digest, actually. Fiber is just what you send to your microbiome. And by the way, we don't-- When we measure the calories from food, we're not taking into account the, the contribution from our microbiome. So all those bacteria that are... Once the f- celery passes through your, you know, the fiber from the celery passes into your colon, there are all these happy bacteria in there, delight- lighted that you had the celery, and they're breaking that celery down into what's called short-chain fatty acids, of which you c- which you then up- take up into your bloodstream and then you use. So we think actually that for some people, maybe about 10% of the energy that they get from their food is not even measured on those nutrition facts labels because it's our, comes from our microbiome. We have no idea really. When you have studies that tell you how much energy somebody's eating, they're making it up. Or not making it up, they're estimating it, and, and it's actually extremely inaccurate, which is another problem with our studies of calories in versus calories out, 'cause nobody really knows how many calories go in.
- 1:43:06 – 1:51:40
“Healthy” Foods That Could Be Making You Worse
- CWChris Williamson
Modern food environment, novel, calorie dense, hyperpalatable, processed, et cetera. But as soon as you create a problem, solutions come out for that too, and we have modern technology, and people can design new foods. What are some of the foods that people are eating every day that they think are healthy, but it's actually making them worse?
- DLDaniel Lieberman
I don't know. Um, I worry about some of the ultra-processed, um, um, uh, foods that, um, that like, like meal replacements, um, for lack of a... I hope I don't get in trouble, but like Huel and Soylent. I mean, there's all k- I mean, you, you could li-- And I actually tried [chuckles] them for a few weeks. Um, I didn't eat dinner, but I had all my lunches and breakfasts. I, I-
- CWChris Williamson
How was that?
- DLDaniel Lieberman
It was awful, actually, 'cause I, it got so boring, and I got to really fear, you know... I mean, at first you're like, "Okay, it's a milkshake. It's not so bad," et cetera. But after a few days it was like I really missed food. Um, um, but there's like emulsifiers in there. There's all kinds of stuff in there that we don't know what they're doing. We're just guessing.
- CWChris Williamson
Mm.
- DLDaniel Lieberman
Um, and, and, and, you know, over months, weeks, years, you have no idea. Or a- another example would be, uh, a lot of people eat a lot of soy products because they think, you know, they're trying to be very vegetarian. That's fine. Nothing wrong with being a vegetarian. They're eating a lot of soy, but some soy products, um, are, um, are made by des- by, by s- through solvents. They use hexane. You don't want hexane in your food. Hexane is, is-
- CWChris Williamson
Sounds like some shit that I'd put in my barbecue
- DLDaniel Lieberman
... yeah, or your, in your car, right? You know? [chuckles] It's a, it's a solvent. It's a flammable solvent, and, and, and then you try to wash the hexane out, but hexane is a, is a toxin. It's a neurotoxin. And, um, and, and studies have shown that you can actually measure people's urine, and people who, who, who are not in the petroleum industry, and they have hexane in their urine. Uh, and it's probably coming from soy or s- from s- uh, non-expeller pressed seed oils. So, like when I get canola oil, I only get expeller pressed canola oil because I don't want my canola beans, you know, uh, s- uh, dissolved with hexane in order to get my oil.
- CWChris Williamson
Hmm.
- DLDaniel Lieberman
Um, and so-
- CWChris Williamson
I thought seed oils were bad for you.
- DLDaniel Lieberman
Oh, no. Uh, that's, that's... There's... That, that's another one of those myths, I'm sorry to say. Um, um, but let's go-- we'll get to that in a second. But, uh, so I think there are some foods that people think are healthy, but the way in which they're processed might be unhealthy.
- CWChris Williamson
Mm-hmm.
- DLDaniel Lieberman
And again, it's very... It's, again, as Paracelsus said, "It's the dose that makes the poison." We don't yet know. It's very hard to do the studies. You can give huge amounts of, like, these foods to rats, and they get cancer, but we just don't know about humans, so depends on what your null hypothesis. So right now, the government's null hypothesis is that this hexane that we get in our food is okay. It's generally recognized as safe. Others think, "Well, unless you can prove it's safe, I don't, I don't want anything to do with this."
- CWChris Williamson
Mm-hmm. Seed oils.
- DLDaniel Lieberman
Seed oils. Okay, so the idea behind seed oils are there, there are different kinds of, um... little, little jargon here. There are different kinds of, um, polyunsaturated fats. So a polyunsaturated fat... So fats are these long chains of carbon, lots and lots of carbons, and, and if the carbons have single bonds between them, remember single bonds from chemistry? That means that they can have two hydrogens, one on each side, that bind to them. So a saturated fat is all single bond carbons, and that each carbon has two hydrogens, so that's saturated with hydrogen. That's why it's called a saturated fat. If you make one of the carbons a double bond, n- now you don't have the hydrogen next on it, and that creates a kink in the fatty acid. So that's why, um, fat, fatty acids that have, have, have a double bond are either mono or polyunsaturated. So mono is one double bond. Poly means there's more than one. That's why they're liquid at room temperature. They have kinks, so they're, they, they fold up. So it turns out that... And they, and we, and we label polyunsaturated fats by where those double bonds are. So like an omega f- so remember in the Greek alphabet, alpha, omega? Alpha's the beginning, omega's the end.
- CWChris Williamson
Mm-hmm.
- DLDaniel Lieberman
So omega-3 means that the double bond is three carbons away from the end. I don't know if this is too much information. So, so o- omega-3 fatty acid has, um, is, um, is the double bond's three carbons from the end. An omega-6 fatty acid is, is six bonds from the end. And so fish, um, are really rich in omega-3s. Omega-3s are great for you. Nobody disputes that. Omega... Eat, eat, eat, eat, eat a shit ton omega-3s, good for you, good for your brain, good for your nervous system, good for your immune system, et cetera. Omega-6 fatty acids used to be much more rare in our diet, and so the paleo diet, I think it started with the paleo diet. Paleo diet said, "Well, look, you know, we should... We didn't evolve to eat that many omega-6 fatty acids because we didn't have seed oils, and so we should try to have a, like a hunter-gatherer kind of omega-3 ratio." So trying not to have more than twice as many omega-6s to omega-3s. And the ar- and the argument behind that is that the, the omega-6 fatty acids can be turned into a, by your digestive system, to another thing called arachidonic acid, which can then be turned into an inflammatory compound, like a prostaglandin that gives you, like, a headache, right? So they c- so there, there is a biochemical pathway by which these fatty acids can become inflammatory. So that's the concern. However, [chuckles] people have done studies. They give people like you and me, they go, go, go sit in a lab. They give people omega-6 fatty acids and then measure w-whether their metabolism does that. Turns out that doesn't. There's no evidence, and, and there are quite a few studies, my book cites them, you can go look them up, where, where the, the, the increasing the amount of omega-6 fatty acids actually increases inflammation. It was a, it's, it was a fear, but the fear t-turns out not to be the case. Furthermore, there's epi- so that's mechanistic study. There's now epidemiological studies as well, which show that people who eat a lot of omega-6 fatty acids do really well. In fact, people eat... In fact, omega-6 fatty acids have s- been shown to be more preventive, like the Nurse's Health Study and various other big, huge studies. We're talking hundreds of thousands of people, prospective studies over decades, actually have lower risks of heart disease, cancers, et cetera, than people who don't eat them. So, so although there were concerns about them, the evidence, if you're, if you're just purely evidence-based-
- CWChris Williamson
Hmm
- DLDaniel Lieberman
... the evidence suggests you should stop worrying about omega-6 fatty acids.
- CWChris Williamson
If you walked through the average healthy person's cupboard, kitchen, what do you think would concern you most?
- DLDaniel Lieberman
The average healthy person's?
- CWChris Williamson
Yeah. Someone that considers, "I'm eating a modern, healthy diet. I'm the sort of person that shops at Whole Foods. I try and make sure that I'm remotely paleo and naturalistic informed when it comes to my diet. I'm a healthy person." You're going through my kitchen. What are the common things you think would concern you most?
- DLDaniel Lieberman
That's a good question. I don't know. I mean, I think w- what's g- I think the more I study diet, the more I realize that there's incredible variety of foods that we're able to eat. Uh, so you're asking, like, what's a, an unhealthy food that people think that's healthy-
- CWChris Williamson
Yes
- DLDaniel Lieberman
... that they tend to eat a lot of? I need to think about that. I'm not sure.
- CWChris Williamson
Good.
- DLDaniel Lieberman
Good question.
- CWChris Williamson
Yeah, yeah, yeah.
- DLDaniel Lieberman
You stumped me there. I guess I'm not a very judgmental person, actually, so that's part... Maybe that's one of the reasons I was struggling.
- 1:51:40 – 1:54:08
Do Diets Stop Working Eventually?
- CWChris Williamson
Yeah. Why does almost every successful diet eventually stop working?
- DLDaniel Lieberman
Do they? I mean, there are some that keep working. I mean, uh-
- CWChris Williamson
Do-- how-- when you look at people longitudinally over time and somebody does a diet, how many of them that lose weight maintain that weight loss?
- DLDaniel Lieberman
Well, again, um, there are, you know... Various studies, uh, have shown that a, a lot of, like, standard traditional diets, people do fall off them. Um, and they're-- the numbers run all over the place. But yeah, I would say that probably a reasonable estimate is about seventy-five percent of people fall off their diet. And why? Because they can't sustain them. Um, again, going back to the Natural Weight Loss Registry that I mentioned earlier, the people who manage to s- to keep-- lose weight and keep it off are the ones who manage to keep the diet going. And what's interesting is that many of them don't follow an actual prescribed diet. They just avoid junk food. They avoid foods with a lot of sugar. They avoid foods with a lot of added fat. Um, they cook most of their meals at home. They tend to exercise. They tend to weigh themselves on a regular basis, so they're keeping track of how they're doing. But very few of them actually are following an Atkins diet or a this diet or a that diet. They're just trying to eat reasonably sensibly.
- CWChris Williamson
Mm-hmm.
- DLDaniel Lieberman
Uh, that's the, that's the evidence. Um, uh, so I think it's... You know, the old joke is, you know, the, the, the, the, um, you know, the best-- the worst part about a diet is the second day on the diet 'cause, uh, 'cause you stop... You, you know, that's when you stop the diet, right? M-many diets... Remember the difference between efficacy and effectiveness.
- CWChris Williamson
Yeah.
- DLDaniel Lieberman
Many-- Most diets are effective.
- CWChris Williamson
In vitro, wonderful.
- DLDaniel Lieberman
I mean, most diets have high efficacy, but they have low effectiveness because-- and they've-- low effectiveness is generally because we have a hard time maintaining them, and that's because of our food environment.
- CWChris Williamson
Does the body fight weight loss very aggressively?
- DLDaniel Lieberman
Absolutely. Yeah. I mean, the biggest one is hunger, right? When you lose weight, your body sends all kinds of signals. There are leptin and, uh, there are peptides, PYY, et cetera, that tell your body, "You are losing weight," and turn on your appetite, and that's why-
- CWChris Williamson
Ghrelin in the stomach.
- DLDaniel Lieberman
Yeah, ghrelin, exactly. I mean, it's very hard to fight all those, all those deep and fundamental adaptations. And, and so the best diets are the ones that kinda trick your body, uh, but also require, um, um, um, you know... They're hard, and, and that's why GLP-1s have been so incredibly successful, because GLP-1s, for many people, just turn off that appetite and enable them to
- 1:54:08 – 1:59:40
The Biggest Concerns About GLP-1s
- DLDaniel Lieberman
eat less. And that's-
- CWChris Williamson
What do you think about GLP-1s?
- DLDaniel Lieberman
Well, I mean, they're game changers for many people. I mean, they've, they've, they've been incredibly successful. Some people lose twenty-five percent of their body weight, and there are new ones being formulated that may be even-- they may be more powerful. So for, for s-- I mean, that can be really huge for somebody to really lose that kind of weight and turn off those cravings. Um, but there are some concerns. So we published-- my colleagues and I published a paper in JAMA, the Journal of the American Medical Association, recently. One of the big concerns about, about GLP-1s is that people not only lose fat, they also lose muscle. And they, and they seem to lose a lot of muscle. It's a bit like bariatric surgery, too. Like, when you lose a lot of weight really fast, uh, people lose a lot of muscle, and that can put you at serious risk of frailty when you get older, 'cause when you lose muscle as you age, you get-- you can get what's called sarcopenia. Sarco is the Greek word for flesh, and penia is loss, so flesh loss. Sounds bad, doesn't it? And sarcopenia is really debilitating because as it becomes a vicious cycle, because as you become less strong, you know, just get-- doing acts of daily living become harder, getting up from a toilet, you know, shopping and doing stuff. And then you become less physically active, and, and you become-- get into this vicious cycle-
- CWChris Williamson
Mm-hmm
- DLDaniel Lieberman
... and things get worse and worse. My-- Basically, my, you know, my, my mother, for lack of better... You know, she, she died essentially of sarcopenia. She got more and more frail as she got older. I tried to get her to eat anything, you know, ice cream, this. Yeah, you name, you know, whatever, to try to put on some weight, and she just couldn't. Um, it's-- was really hard to watch. And-
- CWChris Williamson
Some people are kind of self-enforcing that inability to eat food through GLPs.
- DLDaniel Lieberman
Right. And, and, and so, so the, so the-- One of the big concerns about GLP-1s is that if, if you're taking them, do strength training, please, because that can help reverse or help you maintain your muscle as you lose those GLP-1s. So that's one concern about GLP-1s. Uh, another is that a lot of people quit them. Uh, the last study I saw-- And again, things may change 'cause there are now oral versions of the pill. There, there now-- There's now pill versions. You don't have to inject it. But something like sixty percent of people who've tried GLP-1s have quit them after a year or two. Sixty percent. And the problem is that when you quit them, your body just still will-- Your appetite comes roaring back, and you wanna go back to your previous weight for, for reasons that we do not understand. Um-
- CWChris Williamson
So most people who use GLPs take them for a period of time that they can lose an appreciable amount of weight and then stop Don't maintain the weight loss
- DLDaniel Lieberman
Exactly. That's-
- CWChris Williamson
So it's a lifetime contract
- DLDaniel Lieberman
... so exactly. So that's, that's what we're currently seeing at the moment. Um, so that's, that's a concern because then when they regain the weight, they tend to regain it almost completely as fat, not as muscle, and so then in a way they're worse off.
- CWChris Williamson
Oh, so they've lost muscle on the way down and gained fat on the way back up.
- DLDaniel Lieberman
Yeah, so that's one of the concerns.
- CWChris Williamson
Oh.
- DLDaniel Lieberman
I mean, but look, we're still-
- CWChris Williamson
That's gnarly
- DLDaniel Lieberman
... we're conducting this experiment in real time without knowing the results. And then a final concern about GLP-1s is that, look, nobody likes taking medications, right? At least most people don't like taking medications. And, and it doesn't solve the problem of what you should eat in the first place, and it doesn't prevent obesity in the first place. So it's great for people to lose weight, but we also need to focus on helping the people not have to take those GLP-1s in the first place, so I'm a little worried that we're gonna take our eye off the ball. And even if you're on a GLP-1, you still have to figure out, like, what to eat.
- CWChris Williamson
What do I eat?
- DLDaniel Lieberman
And, and the GLP-1 might help you with your cravings for, you know, really fatty, sugary foods, but it might not. We just still haven't done those studies very well. So, so look, they... I think they're a useful tool for a lot of people-
- CWChris Williamson
Mm
- DLDaniel Lieberman
... but I think we have a lot to learn, and we have to figure out how to use them better. They're not going away, but, um, but I think they're... You know, again, they're not the magic bullet that some people think they are. They- like, but they may be very, very helpful for some folks.
- CWChris Williamson
It feels like a- an artificial solution to an artificial problem. We have this novel food environment which, like, we shouldn't be in, right? In an ideal world, if we were to design things better. And we now have this thing which kind of solves it. We solve the calorie-dense, hyperpalatable food world with this thing that comes in and puts the kibosh on our ability to either eat or gut motility, you know, level of hunger-
- DLDaniel Lieberman
Yeah
- CWChris Williamson
... and stuff like that.
- DLDaniel Lieberman
Yeah, so I, I, I... A few-- About, uh, 13 years ago, I wrote a book called "The Story of the Human Body," and in the, in the end of that book, I propose a, an idea called disevolution. Disevolution is when we treat the symptoms, not the causes of a mismatch disease. So we're talking about mismatch diseases. These are, these are illnesses that are caused by not being adapted to our modern world, right? But when we treat the symptoms, not the causes, we keep the system going, right? Um, and, and I think GLP-1s might be an example of a kind of a disevolutionary process. We can still have our, you know, frozen pizzas and our, you know, f- fried chicken and our, you know, donuts and all that kind of stuff. Now we ta- get, get, get obesity, take the GLP-1s, but we still have that same food system.
- CWChris Williamson
I'll just eat 1,700 calories of the frozen pizza and the donuts-
- DLDaniel Lieberman
[laughs]
- CWChris Williamson
... and whatever.
- DLDaniel Lieberman
We still have that food system that's gonna keep going, right? We need to solve our food system problems if we're gonna help prevent people from getting the... And the-- And, and, and right now, we're not doing enough to help each other eat what-- eat sensibly so that we don't gain weight.
- 1:59:40 – 2:07:35
The Principles Behind Every Healthy Diet
- CWChris Williamson
It seems to me when you get to kind of that point of the conversation, the food environment is predatory, engineered, capitalistic, uh, uh, uh, designed to hook people. Um, people tend to split in one of two ways. One is they go towards systemic change. Um, we need grass to be, uh, changed. We need to look at what can SNAP payments be spent on. We need to kind of step in and, uh, there should be a, a additive restriction. We can't have these food dyes, and some of that stuff's been-
- DLDaniel Lieberman
Regulation
- CWChris Williamson
... yeah, yeah, a degree of top-down sort of bureaucracy that'll come in and fix it. And then the other side is aggressive agency. It's you need to take control of this. No one's coming to save you. Uh, you know, constrain yourself only to the outer aisles in the supermarket or shop in one that, that doesn't have any of the hyperpalatable stuff. Like, across all of this research and self-experimentation, what are the most robust principles that you think people should take away when it comes to having a good diet, nutritionally complete, and evolutionarily, at least not totally, uh, deranged?
- DLDaniel Lieberman
Um, avoid processed foods. I mean, and by processed, I would include foods that are refined, so white flour. Um, I would include, you know, foods that have a lot of added sugar, foods that have a lot of added fat. You know, fat's not your... as bad as maybe some people think, but filling your food with fat and sugar is certainly not great for you. Um, avoid foods that have-- I, I avoid foods that have really weird ingredients that I have no idea what the hell they are. Um, you know, things like maltodextrin. If, if, if you see maltodextrin in your food, run away.
- CWChris Williamson
Why?
- DLDaniel Lieberman
Maltodextrin is a kind of sugar that your body can't actually detect as sugar. It's used as an emulsifier, so it keeps food from-- particles from breaking apart. So if foods have a long shelf life, it makes things creamier and smoother, but it's re- wreaks havoc with your metabolism. So it's, it's a, it's a food you would never eat on your own. It's a chemical additive.
- CWChris Williamson
It's a sleeper agent.
- DLDaniel Lieberman
It's a chemical additive to, to me is like a, like a canary kind of in the coal mine kind of evidence that this is a ultra-processed food I don't want to have anything to do with. So if I see malt- malt- maltodextrin on a food, I do not touch it, right? Um, we need-- so we need to educate ourselves. Again, you know, our ancestors needed to know a lot how to get their food. Now, unfortunately, like it or not, we need to know how to choose our food, and we don't teach this in school. They don't even teach it to medical students. You know, medical schools, you know, uh, RFK Jr. is right on this regard, that, you know, most physicians are given very little training in nutrition. I teach my undergraduates more nutrition. I tell them in my, their lectures, "You're gonna [chuckles] get more from me than you're gonna get in medical school." And that's crazy, right? Why-- We teach kids in school, we teach them geometry, we teach them American history, we teach them... I mean, there's nothing wrong with geometry and American history. Why don't we teach- We teach them chemistry, but why don't we teach them-- when we teach them chemistry, let's teach them the chemistry of food so that they, they learn about-- when they learn about chemist- you know, chem- you know, carbon bonds and hydrogen bonds, et cetera, why not teach them that chemistry in the form of so that they understand saturated fats versus unsaturated fats? Why, why don't we teach this stuff so that we can all learn? Because it's-- right now, all this stuff I'm, I'm talking about is, is c- some of it's considered arcane knowledge, but it's actually not that complicated. Um, and I, and I think most of us can learn this. I mean, I, I tried to put it in the book so that, you know, anybody can learn it. But, but, you know, unfortunately, that, that's, that's part of the, the puzzle. But the, the fact of the matter is a lot of us aren't gonna learn that stuff.
- CWChris Williamson
Hmm.
- DLDaniel Lieberman
And so we need to help helping ourselves, because I think most people would not wanna get obese. Most people want to eat a healthy diet, but they're stressed. They're, they're, they're, they're... You know, their finances are limited. They don't have a lot of time. Imagine you have a-- you commute, you have kids, you rush to the supermarket, you don't have a lot of time to be... You know, whatever. We can't get rid of processed foods, but if we could help have processed foods that are more healthy, I think that's the solution. And so like in England, for example, like when you go to the supermarket in England, there are the green, yellow, and red labels, right? They're super easy, right? And the... You know, I mean, you can debate the fine points about whether they've got the labels right, but for the most part, they're pretty sensible, and they're a quick way for somebody to see, "Oh, you know, this is good for my kids, and this is less good for my kids." Why can't we do that? It's so simple, right?
- CWChris Williamson
It's not-
- DLDaniel Lieberman
Green, yellow, red and red. So, and then you're not forcing anybody. You can, can still buy the red label food.
- CWChris Williamson
Just informed choice.
- DLDaniel Lieberman
Yeah, just give people more information. And, uh, so we can... We, we could do more. Another, another opportunity is to tax. We tax cigarettes. Cigarettes, we all-- everybody agrees cigarettes are bad for you, right? Everybody agrees that cigarettes... We don't prevent people from smoking, and I, I'm not gonna prevent somebody from smoking if they want to. But we, we, we, but we've agreed as a society that cigarettes should be taxed.
- CWChris Williamson
Hmm.
- DLDaniel Lieberman
Why don't we tax junk food? I mean, they're, they, they cause probably, you know-
- CWChris Williamson
Is there no additional tax on sugary or-
- DLDaniel Lieberman
No
- CWChris Williamson
... hyper-processed?
- DLDaniel Lieberman
No, and in fact, in Mexico, when they tried to, uh, put a tax on, on, on soda, uh, the, it got fought by the big, uh... by the, like Coca-Cola-
- CWChris Williamson
Big Soda
- DLDaniel Lieberman
... and soda, yeah, and, and, and, and the, and the tax was reversed. So no, we don't. Uh, so a- again, I'm not saying we should, but, but we should be having a public discussion about this, 'cause it's a, it's a, it's a problem that's larger than any one of us.
- CWChris Williamson
Hmm.
- DLDaniel Lieberman
It's a public health issue that we all pay for, um, um, because it's, it's, it, it's... a- and it's... You know, there's never gonna be one solution. I, I'm a bit of more of a libertarian paternalist. I think that... And I'm not into pretending, you know, telling people what they should do. But I think we should have-- we need help helping us do what we would actually like to do.
- CWChris Williamson
Hmm.
- DLDaniel Lieberman
And, and often we don't know what's in our food, or we don't know what the effects of the foods are. So, or for example, fruit roll-ups. You go to the supermarket and you buy fruit roll-ups, and this says, "Made with real fruit, filled with vitamin C." Well, very few kids are vitamin C deficient. And yes, it's made with real fruit, but they've removed all the fiber. So a fruit roll-up is basically like a form of candy, right? Um, but, but the advertising allows... You know, advertisers are allowed to basically misinform-
- CWChris Williamson
So that might be another one of the, "I think it's healthy," but in reality it's not, and it's in a healthy person's kitchen.
- DLDaniel Lieberman
It's not. And so it, it deserves a red label. Now, if you want to get a fruit roll-up, fine, but you should know that it's not a healthy food.
- CWChris Williamson
Hmm. Scary stuff. I mean, look, it doesn't surprise me that America is kind of the battleground for this. You'd, uh... think french fries from McDonald's in the US have got 18 ingredients, and in the UK they've got three, and one of them's salt, and that one's optional. So this really is, you know, patient zero as a country in wonderful, uh, meritocracy, free market, American Dream thing. But if you take those reins off, you... there's gonna be some pretty negative consequences, and the only way that you can step in is to reconstrain yourself through your own choices, or then have some bureaucracy come in to start to restrict optionality for people.
- DLDaniel Lieberman
Yeah. I think, I think most people would like help-
- 2:07:35 – 2:08:12
Where to Find Daniel
- CWChris Williamson
Daniel Lieberman, ladies and gentlemen. Daniel, you're great. Your work's awesome. Where should people go to check out the book and everything else that you got going?
- DLDaniel Lieberman
Uh, well, Fed Up comes out August 11th, and I tried to make it fun and, and, and readable and with information that I think all of us, uh, need. And it's filled with references, so you can find, you know, endnotes so you can find the data yourself.
- CWChris Williamson
Heck yeah. I appreciate you. Thank you.
- DLDaniel Lieberman
Thank you.
- CWChris Williamson
All right. Bye, my beauties. Dude, yes. [upbeat music] So fun. Thank you very much for tuning in. If you enjoyed that episode, YouTube knows who you are deeply. It thinks you're gonna like this one even more. Go on, press it.
Episode duration: 2:08:13
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Transcript of episode f2p1YH0-BaI
