The Science of Eating for Health, Fat Loss & Lean Muscle | Dr. Layne Norton

1. 0:00 – 2:53

   Dr. Layne Norton, Nutrition & Fitness

   1. AHAndrew Huberman0:00

      (instrumental music) Welcome to the Huberman Lab Podcast, where we discuss science, and science-based tools for everyday life. I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today my guest is Dr. Layne Norton. Dr. Norton is one of the foremost experts in protein metabolism, fat loss, and nutrition. He did his degrees in biochemistry and nutritional sciences, and is considered one of the world experts in understanding how we extract energy from our food, and how exercise and what we eat combine to impact things like body composition and overall health. Today we discuss an enormous number of topics under the umbrella of nutrition and fitness, including for instance, what is energy balance? That is, how do we actually extract energy from our food? We also discuss the somewhat controversial topic of artificial sweeteners, whether or not they are safe or not, and whether or not they are an effective tool for weight loss and particular for people suffering from obesity and different types of diabetes. We also talk about gut health, that is the gut microbiome, and how it's impacted by food and how it can actually impact the metabolism of the foods that we eat. We also discuss fasting or so-called intermittent fasting or time-restricted feeding, what it does and what it does not do in terms of how effective it is for weight loss, and perhaps even for health and longevity. We also talk about protein, and define very clearly how much protein each and all of us need depending on our daily activities and life demands. We discuss the various types of diets that you've probably heard about, including ketogenic diets, vegan diets, vegetarian diets, and pure carnivore diets as well as more typical omnivore diets, and how to make sure that you get all of the essential amino acids that are critical for healthy weight maintenance, weight loss, or directed muscle gain. We also talk about supplements, in particular the supplements for which there is an immense amount of science pointing to their safety and efficacy for fitness and for overall body composition. What I'm sure will become clear to you as you hear Layne talk about each and every one of these topics is that he has an incredible ability to both understand the mechanistic science but also the real-world applications of the various discoveries that are made in particular papers, and in particular, in the randomized control trials. That is, when a given scientific hypothesis has been raised, he's extremely good at understanding why it was raised, but also at evaluating whether or not it works in the real world, which is what I believe most everybody out there is concerned with. I think this is one of the things that really distinguishes him from the other voices in the nutritional landscape. I assure you that by the end of today's discussion, you will have a much clearer understanding about what the science says about nutrition, about fitness, and about how different diets and fitness programs combine to achieve the results that

2. 2:53 – 6:50

   LMNT, ROKA, InsideTracker, Momentous

   1. AHAndrew Huberman2:53

      you want. Before we begin, I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford. It is, however, part of my desire and effort to bring zero cost to consumer information about science, and science-related tools to the general public. In keeping with that theme, I'd like to thank the sponsors of today's podcast. Our first sponsor is LMNT. LMNT is an electrolyte drink with everything you need and nothing that you don't. That means it contains sodium, potassium, and magnesium, the so-called electrolytes, but no sugar. As you may have heard me discuss before on this podcast, every cell in our body, and in particular cells within our brain, the so-called neurons or nerve cells, critically rely on the presence of electrolytes, sodium, magnesium, and potassium, in order to function properly. I myself am a big believer in consuming electrolytes any time I've been sweating a lot, so that could be after or during exercise, or after doing the sauna. So by drinking electrolytes in the form of LMNT electrolyte mix, I'm able to replenish those electrolytes and maintain mental clarity and energy throughout the day. LMNT contains a science-backed electrolyte ratio of 1,000 milligrams of sodium, 200 milligrams of potassium, and 60 milligrams of magnesium. If you'd like to try LMNT, you can go to drinklmnt, spelled L-M-N-T, dot com/huberman to get a free sample pack with your purchase. Again, that's drinklmnt.com/huberman to get the free sample pack. Today's episode is also brought to us by ROKA. ROKA makes eyeglasses and sunglasses that are of the absolute highest quality. The company was founded by two all-American swimmers from Stanford, and everything about ROKA eyeglasses and sunglasses were designed with performance in mind. I've spent a lifetime working on the biology of the visual system, and I can tell you that your visual system has to contend with an enormous number of challenges in order for you to see clearly, for instance when you move from a sunny area to a shady area and back again, whether or not you're looking at something up close or off into the distance. ROKA understands the biology of the visual system, and has designed their eyeglasses and sunglasses accordingly so that you always see with perfect clarity. ROKA eyeglasses and sunglasses were initially designed for activities such as running and cycling, and indeed they are very lightweight. Most of the time I can't even remember that they're on my face they're so lightweight. But the important thing to know about ROKA eyeglasses and sunglasses is that while they can be used during sports activities, they also have a terrific aesthetic and they can be used just as well for wearing to work or out to dinner, et cetera. If you'd like to try ROKA eyeglasses and sunglasses, you can go to ROKA, that's R-O-K-A dot com, and enter the code Huberman to save 20% off on your first order. Again, that's ROKA, R-O-K-A, dot com, and enter the code Huberman at checkout. Today's episode is also brought to us by InsideTracker. InsideTracker is a personalized nutrition program. They analyze the data from your blood and DNA to help you better understand your body and help you reach your health goals. Now, I've long been a believer in getting regular blood work done, for the simple reason that many of the factors that impact your immediate and long-term health can only be analyzed with a quality blood test. One of the major issues with a lot of blood and DNA tests out there, however, is that you get information back about levels of hormones, levels of lipids, levels of metabolic factors, but you don't know what to do about that information. With InsideTracker, they have a easy-to-use platform that allows you to assess those levels and then determine what sorts of behavioral changes, nutritional changes, maybe even supplementation changes you might want to make in order to bring those numbers into the ranges that are optimal for you.If you'd like to try InsideTracker, you can go to insidetracker.com/huberman to get 20% off any of InsideTracker's plans. Again, that's insidetracker.com/huberman to get 20% off. The Huberman Lab Podcast is now partnered with Momentous Supplements. To find the supplements we discuss on the Huberman Lab Podcast, you can go to livemomentous, spelled O-U-S, livemomentous.com/huberman. And I should just mention that the library of those supplements is constantly expanding. Again, that's livemomentous.com/huberman. And now for my discussion with Dr. Layne Norton.

3. 6:50 – 12:35

   Calories & Cellular Energy Production

   1. AHAndrew Huberman6:50

      Layne, Dr. Norton, thank you so much for being here. This is a long time coming, and I have to say, I'm really excited because I've seen you in the social media sphere. I've also listened to a number of your other podcasts. And as a fellow PhD scientist, I feel a great kinship with you. I know you have tremendous experience in, in fitness and nutrition, a number of areas. We also got a lot of questions from our audience, and I'm really looking forward to talking with you today.

   2. LNLayne Norton7:17

      Yeah, I'm excited too. I mean, it's, like you said, it's been something we've been talking about for a long time, so I was glad we were able to make it happen.

   3. AHAndrew Huberman7:23

      Yeah, indeed. And, um, I think some of the audience, uh, has requested a debate or a battle, and I can tell you right now-

   4. LNLayne Norton7:29

      (laughs)

   5. AHAndrew Huberman7:29

      ... it's not going to happen. Actually, one of the things that, um, brought Layne and I together, uh, in conversation online and then via text, et cetera, was the fact that I love to be corrected. Um, and that's what happened.

   6. LNLayne Norton7:44

      (laughs)

   7. AHAndrew Huberman7:44

      I ma- I did a post about artificial sweeteners, which we will talk about a little bit later in the episode, and Layne pointed out some areas of the study that I had missed, um, or maybe even misunderstood, and I revised my opinions, and I think it's wonderful, and other studies have come out since then. So hopefully, our conversation will serve as a, as a message of how, uh, science and actionable science can, um, can be perceived and, and, and that it doesn't always have to be a battle. But hey, if we get into it, we get into it. Um, it won't get physical because we know you would win.

   8. LNLayne Norton8:18

      (laughs)

   9. AHAndrew Huberman8:20

      So, uh, in any case, I'd like to start, um, with something that's rather basic and yet, um, can be pretty complex, um, and that's this issue of energy balance and energy utilization. I think most people have heard of a calorie.

   10. LNLayne Norton8:32

       Yeah.

   11. AHAndrew Huberman8:32

       Um, I am assuming that most people don't actually know what that is in terms of, uh, how it works-

   12. LNLayne Norton8:39

       Okay. Yeah.

   13. AHAndrew Huberman8:39

       ... and what it represents. And so maybe you could just explain for people what happens when we eat food of any kind, and how is that actually converted into energy as a way of framing up the discussion around weight loss, weight maintenance, weight gain, and body composition?

   14. LNLayne Norton8:57

       It's a great question. And like you said, this is one of those things where, you know, people use the term calories in, calories out, and they say, "Well, that's way too simplistic." I'm like, "If you look at what actually makes up calories in, calories out, it's actually very complicated," right? So let's deal with the, uh, what you mentioned first. What is a calorie? Because I think a lot of people don't quite understand this. So a calorie just refers to a unit of energy, of heat specifically. And so, well, what does that have to do with food? What does that have to do with, like, what we digest and eat? Really, what you're talking about is the potential chemical energy that is in the bonds of the macronutrients of food, right? And by digesting, assimilating, and metabolizing those nutrients, we're able to create energy. And the end product of that, mostly, is ATP, um, adenosine triphosphate, which is your body's, uh, energy currency. So to understand ATP, just try to think about if you're trying to power these various reactions in your body, um, we're talking about tens of thousands of enzymes that require ATP, um, you know, it doesn't make sense that you would have to create a bunch of micro explosions, (laughs) right? You want something that can transfer high energy phosphates to power these reactions, to give up, essentially, its energy to power something that might otherwise be unfavorable. So a lot of metabolism is simply creating ATP, which the end of the line of that, I'm going to kind of work backwards, is what's called oxidative respiration. So that happens in the mitochondria. Everybody's heard, mitochondria, powerhouse of the cell. And that is done, uh, through essentially creating a hydrogen ion gradient across the mitochondria, which powers the production of ATP by converting free phosphate plus ADP to ATP. Now, the way that hydrogen ion gradient is created is through, um, you know, creating hydrodoge- hydrogen ions that can be donated through the Krebs cycle. Now, the Krebs cycle is linked to glycolysis. So if we talk about carbohydrate metabolism, carbohydrates basically, other than fructose, get converted into glucose, which can go into glycolysis, and you can produce some ATPs through glycolysis, and then it boils down to pyruvate, then acetyl-CoA, which goes through the Krebs cycle, produces a lot more ATPs from that. Uh, if you talk about protein, protein's a little bit different because protein, uh, gets converted to amino acids, which can be used for muscle protein synthesis or protein synthesis in other tissues. Uh, but it also can be converted through gluconeogenesis to glucose, and there also are some ketogenic amino acids as well. Um, and so you can have a few different ways to get to the Krebs cycle, ei- either being through, um, acetyl-CoA or through glucose going through glycol- glycolysis to pyruvate. Then you have fatty acids, which, um, are able to create energy through what's called beta-oxidation, where essentially you're taking these fatty acids and you're lopping them off two carbons at a time to produce acetyl-CoA, which again can go into the Krebs cycle-... produce those hydrogen ions that can then power the production of ATP. So that's kind of like at the cellular level of how this stuff works. But

4. 12:35 – 15:19

   Energy Balance, Food Labels, Fiber

   1. LNLayne Norton12:35

      stepping back and taking it back out, like, w- what does that have to do with weight loss or weight gain, right? Well, when you think about the balance of energy in versus energy out, sounds very simple. But let's look at what actually makes up energy in versus energy out. First of all, you've got to realize that the energy in side of the equation is more difficult to track than people think, right? So one, uh, food labels, which we like to think as being, you know, like, from upon high, uh, can have up to a 20% error in them.

   2. AHAndrew Huberman13:10

      Really?

   3. LNLayne Norton13:11

      Oh, yeah.

   4. AHAndrew Huberman13:12

      So 100 calorie, something listed as 100 calories per serving, it could, what's actually in there could be-

   5. LNLayne Norton13:16

      Could be 80 or-

   6. AHAndrew Huberman13:17

      ... 80 or 120?

   7. LNLayne Norton13:18

      Right, exactly.

   8. AHAndrew Huberman13:19

      Huh.

   9. LNLayne Norton13:19

      So that's one aspect of it. The second aspect is, there's what's called your energy, but then there's also metabolizable energy, right? So if you have, uh, food stuff with, say, a lot of insoluble fiber, typically, insoluble fiber, uh, is not really digestible, and so you could have, you know, quite a bit of carbohydrate, you know. But if you can't extract the energy from it, and typically, this is because insoluble fiber from, like, plant material, the carbohydrate or/and even some of the protein is bound up in the, uh, plant structure, which makes it inaccessible to digestive enzymes. And so this is what, like, adds bulk to your sch- stool and whatnot, but again, reduces the metabolizable energy in there. And there's some evidence that based on people's individual gut microbiome, that some people may actually be better at extracting energy out of fiber compared to other people. So just starting off right there, okay, there's, there's quite a bit of play in the energy in side of things. Now, one of the things people will say is, "Well, see, that's why you shouldn't worry about tracking calories, 'cause, you know, the food labels can be 20% off." And what I'll say is, "Okay. That's a, that's... I understand where you're coming from. But typically, if it's off, it's going to be consistently off. And if you're consistent with how you track it, e- eventually, y- you'll be able to know kind of what you're taking in." And it's kind of, that's kind of like saying, "Well, don't worry about tracking, you know, if you're..." I, I like to use financial, um, examples. You know, we know that to save money, or you have to earn more money than you spend. Well, you can't exactly know how much money you're earning at a time, you know, 'cause there's inflation and then there's, uh, if you have investments, those can be, you know, different interest rates and whatnot. It's like, okay, but you're, you know, if you have a budget, you have a reasonable idea of what it's going to be, you know? And you make, you make certain assumptions, but you can relatively guess.

   10. AHAndrew Huberman15:17

       Yeah, that's a good example.

   11. LNLayne Norton15:18

       Right.

5. 15:19 – 19:04

   Resting Metabolic Rate, Thermic Effect of Food

   1. LNLayne Norton15:19

      So now let's look at the energy out side of the equation, which is actually way more complicated, right? So your energy out is a few different, uh, buckets. The first one and the biggest one is your resting metabolic rate, so your RMR. And that, for most people, is anywhere from 50 to 70% of your total daily energy expenditure. Now people use the term metabolic rate and energy expenditure kind of interchangeably, but they're not the same thing. So your total daily energy expenditure is the summation of all the energy you expend in a day.

   2. AHAndrew Huberman15:53

      Walking upstairs,-

   3. LNLayne Norton15:55

      Everything.

   4. AHAndrew Huberman15:55

      ... exercise, if you do it.

   5. LNLayne Norton15:56

      Fidgeting.

   6. AHAndrew Huberman15:57

      Aye.

   7. LNLayne Norton15:57

      Yeah.

   8. AHAndrew Huberman15:58

      Plus your resting metabolic rate.

   9. LNLayne Norton15:59

      Right. So resting metabolic rate is a big part of that, but it's not the only thing. So that's usually about 50 to 70%. And sedentary people will be on the higher end of that, so it'll be a bigger proportion. Whereas people who are more active, it'll be a little bit lower, not because their metabolic rate is lower, but because they're expending a greater percentage of their calories from physical activity. Then you have something called the thermic effect of food, which is a relatively small percentage of your total daily energy expenditure. It's about 5 to 10%. Uh, and very difficult to measure and usually, what researchers do when they're kind of looking at this stuff is they just kind of make an assumption about it. They use a constant. Uh, but that's about 5 to 10% of your daily energy expenditure. And that refers to the amount of energy it takes to extract the energy out of food. So think about your body kind of like a car, right? You don't just have gas in your tank and it spontaneously starts up, right? Like, you have to have a battery so you put in energy so you can get the energy out of the, the petrol that you have in your car. Similar with, with food, you can't just eat food and then, you know, it just appears in your cells and you start doing stuff. It has to be systematically broken down and put into forms that can actually produce energy. And so you have to put some energy in to achieve that, and a lot of times people will say something like, "Well, not all calories are created equal." That's not true, because calorie's just a unit of measurement, right? That would be like saying not all seconds on a clock are created equal. Yes, they are. All sources of calories may have differential effects on energy expenditure and appetite. So if we look at something like, um, fat, for example. The TEF of fat is about 0 to 3%. Meaning if you eat 100 calories from fat, your net will be about 97 to 100.

   10. AHAndrew Huberman17:47

       So the process of breaking down that fat e- essentially subtracts some of the, the calories away because you used it in creating energy-

   11. LNLayne Norton17:56

       Correct.

   12. AHAndrew Huberman17:56

       ... by breaking those chemical bonds to create ATP?

   13. LNLayne Norton17:58

       Correct.

   14. AHAndrew Huberman17:58

       Okay.

   15. LNLayne Norton17:58

       Correct. So you have, like, for example, some enzymes that require ATP to run these processes. Now fat is actually the easiest thing to convert into energy. Then you have carbohydrate, which has a TEF of like 5 to 10%. So you eat 100 calories from carbohydrate, and obviously, like, the fiber content makes a big difference on this. But if you eat 100 calories, you'll net 90 to 95. Protein is about a 20 to 30% TEF. So if you eat 100 calories from protein, you're only netting 70 to 80. Now you still net, you know, people say, "Well, you can't eat too much protein." Well-... you know, people will ask, "Well, can protein be stored as fat?" The carbons from protein, it's unlikely it's gonna wind up in adipose tissue. But if you're eating a lot of protein, overall it's part of a lot of calories, it does p- it has to be oxidized and it can provide a calorie cushion for other things to be stored in fat. But protein itself does provide, you know, a net positive for calories, but less so than carbohydrate or fat. And tends to be more satiating. So again, when people talk about, you know, are all calories created equal? Yes, but all sources of calories may have differential effects on energy expenditure and appetite.

6. 19:04 – 25:49

   Exercise & Non-Exercise Activity Thermogenesis (NEAT)

   1. LNLayne Norton19:04

      So that's the TEF bucket and the BMR bucket. Then we go to physical activity and physical activity is essentially two parts. There's exercise, which is kind of your purposeful movements, like you go out for a walk, you do a training session, I mean, whatever. Any purposeful activity. And then you have what's called NEAT, which is Non-Exercise Activity Thermogenesis, which I think is actually a r- really cool.

   2. AHAndrew Huberman19:29

      It's fascinating.

   3. LNLayne Norton19:30

      Yeah, it is.

   4. AHAndrew Huberman19:30

      Yeah.

   5. LNLayne Norton19:30

      So it's, I was actually hanging out with somebody last night and I was noticing them and they, they were fidgeting their feet and their, their fingers and I said, you know, "Have you always, like, been pretty lean?" And they were like, "Yeah, I never really had a pr- problem maintaining leanness." And when you look at the obese resistant phenotype, people think they have high BMR or, you know, they exercise a lot and really what it i- it seems to be is NEAT. They tend to, if they overeat, they just spontaneously increase their physical activity. Now, people get NEAT confused. I've heard people say, "Well, I'm gonna go out for a walk to get my NEAT up." That's not NEAT. NEAT is not something you can consciously modify. What you're doing there, if it's purposeful, it's exercise. So for example, if I, when I'm talking, if I'm waving around my hands, if I'm tapping my feet, if I'm whatever, that's NEAT. But, you know, trying to, like, get yourself, "Well, I'm just gonna tap my foot more," well now, if I'm consciously having to do this, then my focus... I mean, you, you know how the brain works. Very hard to do, you know, you don't really do two things at once.

   6. AHAndrew Huberman20:36

      Right.

   7. LNLayne Norton20:37

      You kind of switch quickly between tasks, right?

   8. AHAndrew Huberman20:39

      Absolutely. Can I quickly ask, uh, was the person that you're referring to our friend, uh, Ben Bruno?

   9. LNLayne Norton20:44

      No. (laughs) No.

   10. AHAndrew Huberman20:44

       (laughs)

   11. LNLayne Norton20:45

       But he is fidgety too.

   12. AHAndrew Huberman20:46

       He has amazing online fitness channel. Um, he's a freakishly strong individual.

   13. LNLayne Norton20:50

       Oh, yeah.

   14. AHAndrew Huberman20:50

       Yeah. And, uh, um, I can't remember whether or not, Ben, you're a fidgeter or not. But anyway, I'll have to go, go check and we'll measure your fidgeting. Um, a- about, uh, non-exercise induced thermogenesis, NEAT, um, my understanding of the old papers on this, old being, I guess, back to the mid '90s-

   15. LNLayne Norton21:08

       Yeah.

   16. AHAndrew Huberman21:08

       ... is that the calorie burn from NEAT is actually pretty significant. We're not talking about 100 calories or 200 calories per day, we're talking about in some cases h- hundreds of thousand, excuse me, hundreds to maybe even close to 1,000 calories per day.

   17. LNLayne Norton21:22

       Yeah.

   18. AHAndrew Huberman21:22

       Could you elaborate on that?

   19. LNLayne Norton21:23

       Yeah. So there was actually a really classic study, I think from, I want to say it's from Levine in 1995, it was Metabolic Ward Study, and hopefully I don't butcher the study because I'm trying to, you know, pull it out of my brain.

   20. AHAndrew Huberman21:38

       I don't expect you to have PubMed in your head.

   21. LNLayne Norton21:40

       (laughs)

   22. AHAndrew Huberman21:40

       Although I must say you have a, a, a quite extensive, uh, PubMed ID, um, grab bag in there. So-

   23. LNLayne Norton21:47

       I try to bring the receipts.

   24. AHAndrew Huberman21:48

       Yeah.

   25. LNLayne Norton21:48

       I try to bring the receipts.

   26. AHAndrew Huberman21:49

       We can put a, we will put a link to this study in the show note captions-

   27. LNLayne Norton21:52

       Yeah.

   28. AHAndrew Huberman21:52

       ... so, um, uh, people can peruse it if they like. Yeah.

   29. LNLayne Norton21:55

       So I, I believe they had people overeat and I, I think it was by, like, 1,000 calories a day and I think for six weeks. And I mean, this is the Metabolic Ward, so they are, this is very tightly controlled. It's as tight as you get. And what was interesting is, of course, on average, people gained weight and gained fat mass, but some people gained more than expected and there was one person in particular who only gained, like, just over half a kilo, right? They should've gained, like, I think it was something like three to four kilos, it was, was predicted, and what they found is this indi- individual just spontaneously increased their physical activity. Like, he didn't purposefully do it, it, it just happened, and I mean, you know, anecdotally, I've seen people who are, again, you know, very lean even eat a meal, sit down, and start sweating, you know? And be very fidgety. There was a, a natural bodybuilder back in the day named Jim Cordova, and this guy was just very lean all the time and he was exactly that phenotype, you know? He would walk up a flight of stairs and all of a sudden he's sweating. Sit down to eat a meal, he's sweating, you know? He just...

   30. AHAndrew Huberman23:03

       He's a furnace.
7. 25:49 – 29:24

   Losing Weight, Tracking Calories, Daily Weighing

   1. AHAndrew Huberman25:49

   2. LNLayne Norton25:49

      Well, what I'll tell people is if, if you're worried about NEAT, one thing you can do, like, these watches for example, people are like, "Oh, well it told me I burned this many calories." The- they are not accurate for energy expenditure. I mean, it is like, there is a meta-analysis in 2018 I want to say, between a 28 and 93% overestimation of energy expenditure by these watches.

   3. AHAndrew Huberman26:15

      Fitness trackers. So for those-

   4. LNLayne Norton26:16

      Yeah.

   5. AHAndrew Huberman26:16

      ... of you listening, we're not gonna name the brand but, uh, fitness trackers, uh, so wrist-worn fitness trackers.

   6. LNLayne Norton26:21

      And this is, and this is across the board.

   7. AHAndrew Huberman26:22

      Okay.

   8. LNLayne Norton26:23

      Um, so like, depending on the brand it could be, you know, more or less, but they all overestimated the amount of ex- the calories you burn from exercise. So this is actually a great example where people go, "Well, calories in calories out doesn't work for me 'cause I ate in a calorie deficit and I didn't lose weight." And, uh, when I talk to them, usually it's they went to an online calculator, it's one- it's a few things, they went to an online calculator, put in their information, it spat, it spat out some calories to eat and they ate that and didn't lose weight. And it's like, well, what do you think is more likely, that you're defying the laws of, you know, um, conservation of energy or that you're- you might have not gotten the right number for you?

   9. AHAndrew Huberman26:59

      The r- the measurement tool was off.

   10. LNLayne Norton27:00

       Yeah.

   11. AHAndrew Huberman27:01

       Yeah.

   12. LNLayne Norton27:01

       The next thing is a lot of people weigh very sporadically and I'll tell people like, "If you're gonna make intentional weight loss a goal," um, and again this can be different for different people but typically I tell people, "Weigh in first thing in the morning or after you go to the bathroom, do it every day and take the average of that for the week and then compare that to the next week's average."

   13. AHAndrew Huberman27:22

       Can I ask one quick, sorry to interrupt-

   14. LNLayne Norton27:23

       Mm-hmm.

   15. AHAndrew Huberman27:23

       ... but one quick question about that.

   16. LNLayne Norton27:24

       Mm-hmm.

   17. AHAndrew Huberman27:24

       When you say go to the bathroom, not to get, um, uh, too detailed, uh, here for unnecessarily but are you talking about urination and, um, emptying-

   18. LNLayne Norton27:33

       Both of them. Yeah.

   19. AHAndrew Huberman27:33

       ... your bowels? Ideally-

   20. LNLayne Norton27:34

       Yeah both of them, yeah.

   21. AHAndrew Huberman27:34

       ... because you could have eaten a big meal the night before.

   22. LNLayne Norton27:36

       Yeah.

   23. AHAndrew Huberman27:36

       Yeah. Got it.

   24. LNLayne Norton27:36

       Yeah.

   25. AHAndrew Huberman27:37

       So wake up, uh, use the bathroom, um, in all, all forms that you're ready and then, and then get on the scale, take that measurement, average that across the week, and then maybe every Monday you'd take that value and see how you're progressing.

   26. LNLayne Norton27:51

       Right, and, and the reason I, I recommend doing that is if you're just kind of sporadically weighing in, a- as somebody who weighs themselves pretty, pretty regularly, I mean, my weight will fluctuate, you know, five, six pounds and not seemingly changing much, you know? And that's just, you know, those short term changes are fluid so I'm- I've had it before where week to week my average didn't change but between the lowest weigh in from a previous week and the highest weigh in might have been like eight pounds, right? So if you're somebody who just randomly is weighing in and you're eating in a calorie deficit and you just weigh in one day where you've just, whatever reason holding some more fluid then you go, "Oh see, this isn't working," when in reality your average might be dropping. So that's one of the reasons and actually, um, believe it or not, uh, weight fluctuations are actually identified as a major reason why people get discouraged from weight loss. Um, that it, it kind of stops the buy-in.

   27. AHAndrew Huberman28:50

       Mm-hmm.

   28. LNLayne Norton28:50

       You know when they have a fluctuation up, so that's one of the reasons early-

   29. AHAndrew Huberman28:53

       Great point.

   30. LNLayne Norton28:53

       ... one of the reasons early on that low carb diets tend to work really well is 'cause people lose a lot of water weight really quickly and they get that buy-in, right? Say, "Oh, this is working."
8. 29:24 – 35:04

   Post-Exercise Metabolic Rate, Appetite

   1. AHAndrew Huberman29:24

      I do have one quick question, and, and, um, I do want, we'll return to NEAT in a moment but when you say the caloric burn as a consequence of exercise-

   2. LNLayne Norton29:31

      Mm-hmm.

   3. AHAndrew Huberman29:31

      ... I want to ask about the caloric burn during that exercise. So for instance-

   4. LNLayne Norton29:35

      Mm-hmm.

   5. AHAndrew Huberman29:35

      ... if somebody's on the treadmill and they'll see, okay, they burned, you know, 400 calories. Actually, I think this is a month where a number of prominent podcasters like Bert Kreischer, Tom Segura, Joe Rogan, others-

   6. LNLayne Norton29:44

      Yeah.

   7. AHAndrew Huberman29:45

      ... are doing, they call it Sober October but in addition to avoiding alcohol they, they're burning 500 calories per day during the exercise.

   8. LNLayne Norton29:50

      Yeah.

   9. AHAndrew Huberman29:50

      They're me- they're measuring it. A lot of people do this. They think- they take track of whether, or excuse me, take stock of how many calories they burned. My understanding is that if that particular form of exercise is a muscle building form of exercise that at some point later there might be an increase in muscle if you did it, everything right, do everything right, and then you will burn more energy as a consequence of adding that tissue. That's a long process as, as you know and we will discuss, but I have heard about this post-exercise induced increase in oxidative metabolism. I'm probably not using the right, uh, languaging here.

   10. LNLayne Norton30:26

       EPOC, yeah.

   11. AHAndrew Huberman30:27

       So if I were to go out for instance and sprint, do some sprints, run hard for a minute, jog for a minute, run hard for a minute, do that ten times over, they'll- let's assume I burn 400 calories during that, um, exercise, um, bout.... but my understanding is that in the hours that follow, my basal metabolic rate will have increased. Is that true? And is it significant enough to care about?

   12. LNLayne Norton30:50

       So I'll answer both those questions. Um, yes, there does seem to be a small increase, uh, in metabolic rate. And no, it does not appear to be enough to actually make a difference. So when they look at... and again, this is where, um, I tell people, I think I have a good perspective on this, because I- my undergraduate degree was a biochemistry degree, so I was very into mechanisms. You know what I mean? It was like, "Oh, if we just do this and this, we'll get this." Right? And then, I did nutrition as a graduate degree, and then my advisor was so great, because y- y- you could do something over here and he could tell you how it would affect vitamin D metabolism over here.

   13. AHAndrew Huberman31:26

       This is Don Laymon.

   14. LNLayne Norton31:27

       Yeah, Don Laymon.

   15. AHAndrew Huberman31:28

       Yeah.

   16. LNLayne Norton31:28

       So h- you know, he would always kind of say, "Yeah, but what's the outcome going to be?" Right? So this is actually one of the things I changed my mind on, was I used to be very much, well, I think, you know, high intensity interval training is probably better because you get this post-exercise energy burn, which they do see in some of these studies, but in the kind of meta-analyses and like more tightly controlled studies where they equate work between high intensity intervals and moderate or low intensity, uh, cardio, so equating work, uh, they don't see differences in the loss of body fat. And so to me, if I'm looking at it, that's the example of a mechanism which is, okay, we're seeing this small increase in basal metabolic rate, that should lead to increased loss of body fat. But again, remember, you're capturing a- a snapshot in time, right? But we don't see a difference in the loss of body fat. So what may be happening, and again, I'm just speculating, but a way to explain it could be, you might have an increase and then you might actually have a decrease that tends to just kind of wash it out. Right?

   17. AHAndrew Huberman32:33

       I see. And I have to imagine some forms of exercise, this would be highly individual, but, um, will spike appetite more than others. So for instance, if I go out for a 45-minute jog or, which I do, a 45 to 60 minute hike or jog once a week, I just make it a point to do that, or ruck or something like that, throw on a weight vest and hike. After that, I find I- I'm very thirsty, I want to hydrate, but I'm not that hungry.

   18. LNLayne Norton32:56

       Mm-hmm.

   19. AHAndrew Huberman32:56

       And that's true of most all cardiovascular exercise for me. Um, but after I weight train, about 60 to 90 minutes later, I want to eat the refrigerator.

   20. LNLayne Norton33:07

       (laughs) .

   21. AHAndrew Huberman33:08

       And so obviously calories in calories out dictates that that will play an important role as to whether or not I gain or lose weight, et cetera. So is it safe to say that the specific form of exercise that people choose, uh, needs to be taken in consideration of calories in calories out? So how much is burned during the exercise? Also, how much that exercise tends to stimulate appetite?

   22. LNLayne Norton33:30

       Mm-hmm.

   23. AHAndrew Huberman33:31

       I don't know whether or not people explore this in- in the rigorous studies.

   24. LNLayne Norton33:33

       Yep.

   25. AHAndrew Huberman33:34

       And whether or not that form of exercise actually increases lean muscle mass or not. Um, so, uh, now we've taken exercise and split it into a number of different dimensions, but this is what, uh, you are so masterful at, is really parsing how the different components work individually and together. So if- if you would just, um, you know, expand on that, I- I'd love to know what you're thinking.

   26. LNLayne Norton33:55

       Yeah. So this is actually a really fascinating thing. Um, so first thing I want to, I want to just go back to talking about like, for example, Bert and Tom and- and Joe, were going to do 500 calories a day on whatever. Um, so those apparatuses don't measure those things effectively either, right? Just like these watches. But the one thing I will say is if you are... like for example, if I do two hours of resistance training, typically this will say I burned about 1,000 calories, right?

   27. AHAndrew Huberman34:21

       That's a lot of resistance training.

   28. LNLayne Norton34:23

       Right.

   29. AHAndrew Huberman34:23

       My w- my weight workouts are like s- are warm up for 10 minutes and then one hour of work, done. (laughing)

   30. LNLayne Norton34:28

       I- I just, I love to train.
9. 35:04 – 36:19

   AG1 (Athletic Greens)

   1. LNLayne Norton35:04

   2. AHAndrew Huberman35:04

      I'd like to take a quick break and acknowledge one of our sponsors, Athletic Greens. Athletic Greens, now called AG1, is a vitamin mineral probiotic drink that covers all of your foundational nutritional needs. I've been taking Athletic Greens since 2012, so I'm delighted that they're sponsoring the podcast. The reason I started taking Athletic Greens and the reason I still take Athletic Greens once or usually twice a day is that it gets me the probiotics that I need for gut health. Our gut is very important. It's populated by gut microbiota that communicate with the brain, the immune system, and basically all the biological systems of our body to strongly impact our immediate and long-term health. And those probiotics in Athletic Greens are optimal and vital for microbiotic health. In addition, Athletic Greens contains a number of adaptogens, vitamins and minerals that make sure that all of my foundational nutritional needs are met, and it tastes great. If you'd like to try Athletic Greens, you can go to athleticgreens.com/huberman and they'll give you five free travel packs that make it really easy to mix up Athletic Greens while you're on the road, in the car, on the plane, et cetera, and they'll give you a year's supply of vitamin D3 K2. Again, that's athleticgreens.com/huberman to get the five free travel packs and the year's supply of vitamin D3 K2.

   3. LNLayne Norton36:18

      What I

10. 36:19 – 43:46

    Exercise & Appetite, Calorie Trackers, Placebo Effects & Beliefs

    1. LNLayne Norton36:19

       will say about the calorie trackers is, so if I'm used to, okay, I usually burn about 1,000 calories according to this, it's not accurate, but if I go in tomorrow and I do 1,300-... it may not be accurate. I don't know what the exact number is, but I can be relatively confident that it's more than the previous session, right? And so, in terms of comparison, it might be okay, like, you know, kind of within subject. Um, and then the other thing that I was kind of circling around on was, if you're worried about NEAT, tracking your steps can be helpful, because people's step counts can spontaneously decrease when they're on a fat loss diet. They don't even realize it. So, uh, and, and that, again, not a complete measure of NEAT, but what we've had some clients do, uh, with our team bio-link coaches is they'll say, "Okay, you're at 8,000 steps right now. We're not gonna add any purposeful cardio. But whatever you need to do to maintain that 8,000 steps, do that." And sometimes they have to add, you know, 15, 20, 30 minutes of cardio because their spontaneous activity, that they're not even aware of, goes down.

    2. AHAndrew Huberman37:21

       That's a really excellent point. I- I- I've heard, you know, the 10,000 steps per day number was, um, we all heard that.

    3. LNLayne Norton37:28

       Yeah.

    4. AHAndrew Huberman37:28

       And then I learned that 10,000 was just kind of thrown out as an arbitrary number. (laughs)

    5. LNLayne Norton37:32

       Yeah. It is a good number.

    6. AHAndrew Huberman37:32

       So like the eight-hour intermittent fasting thing, there's a story behind that, 'cause I actually, uh, spoke to Sauchin and it turns out that the graduate student in his lab that did that initial study, which was on mice by the way, um, was limited to being in the lab for about eight hours by their significant other. (laughs) So the eight-hour feeding window is actually the consequence of this r- person's relationship. Um, it's kind of a-

    7. LNLayne Norton37:53

       That is a, that is a really great point that people don't realize when they, a lot of people will try to copy like scientific studies, and I'll, I'll tell people, like, "Listen, scientific studies are so confined. You, you need to be very careful with how broadly you apply what's in there." Right? Like they're, they're a very big hammer, is kind of the way I look at it. Okay? They're not a scalpel, they're a big hammer. And I think a lot of times in terms of coaching, scientific studies will tell you what not to do rather than what to do, right? Uh, but getting back to your question about like exercise appetite. So first off, I'm not really aware if there's, uh, evidence showing like differential effects of different forms of exercise on appetite. It's possible. Um, but, uh, again, it also could be like a placebo effect, right? Because we, like, for example, you and I grew up in an era where the muscle magazines, it was like, "Well, as soon as you finish your workout, you can have your biggest meal of the day."

    8. AHAndrew Huberman38:49

       That's right.

    9. LNLayne Norton38:49

       Right? And, you know, when I say placebo effect, I think people have the wrong idea of what the placebo effect is. They think that's just a feeling. Placebo effect can actually change your physiology. People don't, people don't realize this. Um, there's research showing that a placebo or the power of suggestion is basically as powerful as some pharmaceuticals. And one of the, the great examples I like to use is actually there was a study we just covered in our research review on creatine, where they did, um, four groups, not supplemented with creatine, told they weren't supplemented with creatine, not supplemented, told they were supplemented, supplemented, told they weren't, supplemented, told they were. Basically, it just matters what they told them.

    10. AHAndrew Huberman39:34

        Really?

    11. LNLayne Norton39:35

        Oh, yeah.

    12. AHAndrew Huberman39:35

        This is incredible. Um, I have to get this study. We'll, uh ... So we can link to it.

    13. LNLayne Norton39:39

        Yeah.

    14. AHAndrew Huberman39:39

        Uh, a colleague of mine at, at Stanford, she's been on the podcast, I'd love to introduce you two, 'cause I think you guys would get, um, really riff. First of all, she was a former D1 athlete.

    15. LNLayne Norton39:47

        Mm-hmm.

    16. AHAndrew Huberman39:47

        Um, and then is, uh, runs a lab at Stanford in psychology, this is, uh, Leah Crum, and she's ... And grew up, um, in, in this, you know, very athletic obviously, and, and very, very smart. And her laboratory focuses on these belief/placebo effects, where if you tell people all the horrible things that stress do to you, in terms of your memory and cognitive functioning, and then you give them a memory test, they, they perform well below baseline. If you tell them that stress sharpens them in the short term, and that adrenaline is this powerful molecule that can, uh, (laughs) really tune up a number of memory systems, memory improves.

    17. LNLayne Norton40:19

        Mm-hmm.

    18. AHAndrew Huberman40:19

        And it, it's remarkable.

    19. LNLayne Norton40:21

        Yeah.

    20. AHAndrew Huberman40:21

        Um, and it's consistent. And, uh, and this, and they've done this for any number of different things and getting-

    21. LNLayne Norton40:26

        And again, these are-

    22. AHAndrew Huberman40:27

        ... food allergies, for instance, you know? Incredible results. In any case, I, I'm, I'm so glad you're bringing this up. Um, I take creatine monohydrate, uh, and I have for years, five grams a day. I don't love-

    23. LNLayne Norton40:38

        And it's great.

    24. AHAndrew Huberman40:39

        And, um, and it's great, and I believe it's great. So ... (laughs)

    25. LNLayne Norton40:42

        (laughs) Well-

    26. AHAndrew Huberman40:42

        So is there a compound effect of believing it's great and it actually, uh, being great?

    27. LNLayne Norton40:46

        So not, not in this study, but, so I think the thing to point out, people will misinterpret that as creatine doesn't work. And that's not what that says. What it says is, your beliefs about what it does are probably just as powerful as what it does, right? So, uh, they actually did a study, and I don't have the citation, but it was, I think, within the last 10 years, where they told people they were putting them on anabolic steroids. And wouldn't you know it, they had better gains. Even though they weren't actually on anabolic steroids, they had better gains than people that they didn't tell were-

    28. AHAndrew Huberman41:17

        Amazing.

    29. LNLayne Norton41:17

        ... anabolic steroids. And that's like hard outcome, strength, lean body mass, you know, those sorts of things. So when people say, "Well, I wouldn't fall for, for the placebo effect." It's like, eh, you don't have to fall for it if, if you believe it to be true. The power of belief is very, very powerful, and as a scientist, I wish sometimes I was ignorant so that I could subject myself to the placebo effect more often. (laughs)

    30. AHAndrew Huberman41:41

        Oh, yeah. Absolutely.
11. 43:46 – 56:32

    Exercise & Satiety Signals, Maintain Weight Loss & Identity

    1. LNLayne Norton43:46

       100% agree. And when you're talking about weight loss, people miss the point of exercise, I think. Y- uh, there's some work that came out from Herman Pontzer as well that basically showed, like, well, if you do 100 calories from exercise, you have a, like, 28 calorie reduction in your basal metabolic rate in response to that. So it's kind of like this constrained energy expenditure model, right? But what I would say is, okay, well, there's still a net of 72, right? So it's still, it's still-

    2. AHAndrew Huberman44:12

       Mm-hmm.

    3. LNLayne Norton44:13

       ... okay. And the other thing is I think the effects of exercise on weight loss are actually more due to what it does to appetite. Um, so if you look at people who lose weight and keep it off for a number of years, kind of outliers because most people don't keep it off for years, over 70% of them engage in regular exercise. Of people who do not keep weight loss, uh, like, maintain weight loss, less than 30% exercise regularly. So now, that's just a correlation, that doesn't necessarily prove causation, but there are some pretty compelling studies showing that exercise increases your sensitivity to satiety signals. So basically, you can have the same satiety signals, but you're more sensitive to them when you exercise. And there's actually a really classic study, um, from the 1950s in Bengali workers where they looked at basically four different quadrants of activity. So you had sedentary, lightly active, moderately active, heavily active, basically based on their, their job choice. And they didn't have an intervention, they just wanted to track them and, and see how much, you know, how many calories did they actually eat. So it was like a J-shaped curve. So the sedentary actually ate more food than the lightly active or moderately active, but from lightly active to heavily active, they almost perfectly compensated how many calories they should be eating. So to me, that suggests when you become active, you can actually rep- regulate your appetite appropriately, or much more appropriately than if you're sedentary.

    4. AHAndrew Huberman45:47

       And do you think this has to do with changes in the brain, brain centers that respond to satiety signals from the periphery, um, and/or do you think it has to do with, uh, changes in br- blood sugar regulation? I, what I was taught, and I don't know if this is-

    5. LNLayne Norton46:02

       Mm-hmm.

    6. AHAndrew Huberman46:02

       ... still considered true is that, you know, spikes in blood sugar will trigger a desire to eat more, even though it's kind of exactly the opposite of what you need when you have a spike in blood sugar. And there's this kind of, and we'll get into this when we talk about artificial sweeteners, there's this idea in mind that I think I adopted perhaps falsely, that, you know, you eat something that's sweet or that tastes really good and, and you are suddenly on the train of wanting to eat more. Um-

    7. LNLayne Norton46:24

       Yeah.

    8. AHAndrew Huberman46:24

       ... and I could imagine how exercise, um, if it is increasing the satiety signals, uh, could be working in a number of different ways.

    9. LNLayne Norton46:32

       Yeah. Uh, I, I think it's a m- m- I think the effect is probably mostly at the brain level. Um, you know, the, the effects on blood sugar, the research out there is not very compelling for blood sugar driving, uh, appetite. Now, if you become hypoglycemic, yes, you'll, you'll get hungry, but it's a different kind of hunger than, like, your normal, like, "I feel kinda empty and my stomach's growling." Like, those are, they can go together, but usually, like, the hypoglycemia is like, "I am hot. I feel like I'm gonna pass out." Like, you want to eat something not because your stomach's growling, but because y- you know that you just need some fuel.

    10. AHAndrew Huberman47:11

        It's like you're getting pulled under.

    11. LNLayne Norton47:13

        Oh, yeah.

    12. AHAndrew Huberman47:13

        Yeah.

    13. LNLayne Norton47:13

        Absolutely.

    14. AHAndrew Huberman47:13

        I've been there.

    15. LNLayne Norton47:14

        Yeah.

    16. AHAndrew Huberman47:14

        I've been there when I've, uh, done longer fasts, something I don't do anymore, and drank a lot of black coffee.

    17. LNLayne Norton47:20

        Mm-hmm.

    18. AHAndrew Huberman47:20

        There was probably an electrolyte effect there because coffee has, you, uh, excrete sodium and other electrolytes.

    19. LNLayne Norton47:25

        Yeah.

    20. AHAndrew Huberman47:25

        And then just feeling like I needed something. This whole thing, like, I need something, this kind of desperation, I, I, I'm, I never want to be back here again.

    21. LNLayne Norton47:32

        (laughs)

    22. AHAndrew Huberman47:33

        (laughs) Hypoglycemia is very uncomfortable.

    23. LNLayne Norton47:34

        Oh, it's not fun. So, you know, again, uh, when they, and when, then when they look at, you know, actual randomized control trials of implementing some exercise where they're, you know, pretty controlled environment, they typically see people, if, if anything, they eat less as opposed to eating more. Now, some people, again, that's, you know, studies report averages, right? And there's individual data points. So there are some people who at least anecdotally report that exercise makes them more hungry. That's completely valid. It's, now, it could be their beliefs around it, it could be a number of different things, but it's important to understand that there is individual variability. And I think one of the things that I've learned to appreciate more is not trying to separate psychology and physiology. We, we do this a lot and say, "Well, I want to know the physiology. I don't care about the psychology of it." And it, now I'm kind of appreciating more psychology is physiology. You know, that, like, with most things now, we have kind of the biopsychosocial model. L- and I'll give you an example of this. A lot of people get really caught up with appetite and-... if we could just suppress people's appetite. That's part of it, but people don't just eat 'cause they're hungry. They eat for a lot of different reasons, social reasons especially. So can you remember the last social event you ever went to that didn't have food?

    24. AHAndrew Huberman48:59

        No.

    25. LNLayne Norton48:59

        Right. Uh, if you look at dinner plates from the 1800s, they're about this big. Now how big are dinner plates?

    26. AHAndrew Huberman49:06

        The whole buffet.

    27. LNLayne Norton49:06

        Right. (laughs)

    28. AHAndrew Huberman49:07

        (laughs) Yeah.

    29. LNLayne Norton49:08

        Um, if you... Uh, there's, um, situational cues, right? You're sitting down to watch TV. Oh, grab some popcorn, grab some, you know, snack, whatever.

    30. AHAndrew Huberman49:17

        I even see this with the, you know how, uh, one person will pick up their phone and then everyone picks up their phone?
12. 56:32 – 1:03:33

    Weight Loss & Maintenance, Diet Adherence

    1. LNLayne Norton56:32

       actually, into one of my f- my favorite topics, which is, you know, why do we have such a hard time with losing weight, but more so keeping it off? Because of obese people, six out of every seven obese people will l- lose a significant amount of body weight in their life. So why do we still have an obesity problem? They don't keep it off. Why don't they keep it off? When you look at the research, basically what it suggests is because people think about, "I am going to do a diet and I'm gonna lose this weight," and they do not give any thought to what happens afterwards, right? It's like, think about if you have some kind of chronic disease or a diabetic, right? You, you can't just take insulin once and that's it, right? You got to take it continuously. Otherwise, you're gonna have problems. Um, if you do a diet and you lose, you know, um, 30 pounds, fantastic. But if you then just go back to all your old habits, y- you're gonna go back to where you were, if not more. Uh, you can't, you can't create a new version of yourself while dragging your old habits and behaviors behind you. So what I'll tell people is, 'cause people say, "Well, I'm doing m- a carnivore diet," or, "I'm doing this diet or that diet." And I'll say, "That's fine. Do you see yourself doing that for the rest of your life?" And if the answer is yes, if you, if you really believe that that's gonna be sustainable for you, and plenty of people, low carb, intermittent fasting, what, whatever, they say, uh, "Felt easy. You know, I could do this forever." Great. What, if you're going to lose weight, you have to invoke some form of restriction, whether it is a nutrient restriction, like low carb, low fat, a time restriction, intermittent fasting, any form of time-restricted eating, or calorie restriction, tracking macros, whatever. So you, you get, you get to pick the form of restriction. So pick the form of restriction that feels the least restrictive to you as an individual and also do not assume that it will feel the same for everybody else, because I made this mistake, whereas like, I, I track things. And so I, I allow myself to eat a variety of foods, I allow myself to eat some fun foods. Uh, but I track everything and I'm able to modify my body composition and be in good health doing that. Now, doesn't feel hard for me. Like, uh, part of it's I've just been doing it for so long. But to other people, that's very stressful. They don't wanna do, they say, "Well, I'd rather just not eat for, you know, 16 hours." If that feels easy for them, do that, because the one thing that, there was a couple of meta-analysis on, uh, popular diets, and basically what they showed was they were all equally terrible for, for long-term weight loss. But when they stratified them by adherence, and none of them were better for adherence overall, but when they stratified people just according from lowest adherence to best adherence, there was a linear effect on weight loss. So really what it says is, what is the diet that's gonna be easiest for you to adhere to in the long term? And you should probably do that. And people, w- again, this is where I step back and take the 10,000-foot view, somebody will say, "Well, I'm gonna do ketogenic because I wanna increase my fat oxidation and I wanna do this," and they're talking about all these mechanisms and everything, and that's great. Can you do it for the rest of your life, right? Is th- is this gonna be something sustainable for you? And if the answer is no, you probably need to rethink what your approach is gonna be.

    2. AHAndrew Huberman59:59

       It's incredibly important message. Um, basically that. (laughs) You know?

    3. LNLayne Norton1:00:06

       Yeah.

    4. AHAndrew Huberman1:00:06

       If I could highlight, you know, if there was a, a version of highlight or boldface and underline in, uh, in the podcast space, I, I would highlight, boldface, and underline what you just said. Um, and for those of you that heard it, uh, listen to it twice and then go forward, because it's absolutely key. I think it also explains a lot of the so-called controversy that exists out there. I think, um, it also crosses over with the placebo effect. I almost want to say...... um, pick the, the nutrition plan that you think you can, uh, stick to for, for a long period of time, ideally forever, and pick your placebo too, because there j- there is a lot of placebo woven into each and every one of these things, intermittent fasting, uh, keto, probably even, um, vegan versus omnivore versus carnivore. Right?

    5. LNLayne Norton1:00:49

       Well, they even talk about, um, you know, the diet honeymoon period, right, where, like, you go into a diet and you're all fired up about it, and, like, you're very adherent, and then what happens with every single diet, without exception in research studies, is once you get past a few months, adherence just starts waning.

    6. AHAndrew Huberman1:01:04

       So then-

    7. LNLayne Norton1:01:04

       And going off.

    8. AHAndrew Huberman1:01:05

       ... here we are really talking about a form of relationship (laughs) , you know? I'm not- I'm not saying that to be tongue in cheek. Actually, we had a guest early on in the podcast, Dr. Karl Deisseroth. He's a psychiatrist and, um, bio engineer at Stanford, um, tremendously successful, Lasker Award winner, et cetera, and he talked about love as a sort of a, a, an interesting aspect of our psychology where it's a story that you co-create with somebody but that you live into the future of that story. You know, when you-

    9. LNLayne Norton1:01:34

       Mm-hmm.

    10. AHAndrew Huberman1:01:34

        ... t- pair up with somebody, that, we- he was referring to romantic love-

    11. LNLayne Norton1:01:36

        Mm-hmm.

    12. AHAndrew Huberman1:01:37

        ... that there's this sort of mutual agreement to create this, this idea that you're going to live into. So it's not just about how you feel in the moment. It's also that you project into the future quite a lot. I'm seeing a lot of parallels with, um, a highly functional and effective diet. And, um, and I love it. I'm not, uh, setting this parallel up artificially. I- I'm setting it up because I think that ultimately it, it boils, uh, down to what you said earlier, which is that the brain and our decisions about what we are going to stick to are tremendously powerful.

    13. LNLayne Norton1:02:05

        And, and I think one thing I will say is, like, keep in mind, um, when you look at the, uh, research data, the meta-analyses on, say, time-restricted eating versus non, when calories are equated, doesn't seem to be a difference in, in weight loss, fat loss, and most biomarkers of health. Same thing for low carb versus low fat. If you equate calories and protein, there w- there was a meta-analysis done by Kevin Hall back in 2017 where they looked at the, and again, actual loss of body fat, and another important point was there was, I think there was 22 studies in this, but all of them provided food to the participants, right? That's important because that makes, m- ensures that adherence can be much higher in those studies, whereas, like, various free living studies, sometimes you can see funky results.

    14. AHAndrew Huberman1:02:47

        People are sneaking food or, or they're just not really-

    15. LNLayne Norton1:02:51

        It's very difficult.

    16. AHAndrew Huberman1:02:51

        ... eating the way that the study would ideally have them eat.

    17. LNLayne Norton1:02:54

        Unless, unless the person is getting, like, continuous support. Like, studies where they have a dietician talk to people, like, every week tend to actually have pretty good adherence. But, I mean, that's expensive to have done in a study, and again, like, what limits studies? Money, money, and money, right? Um, but the low carb versus low fat when protein and calories are equated, basically no difference in fat loss. Now some people get upset about this, but it's like, well, to me that's like, this is great because you get to pick the tool you want. The one tool, it doesn't seem to be that much better than another, so pick the one that works for you, right? Whatever lever you've gotta pull, you've got a bunch of different options.

    18. AHAndrew Huberman1:03:32

        You

13. 1:03:33 – 1:08:03

    Restrictive Diets & Transition Periods

    1. AHAndrew Huberman1:03:33

       mentioned, um, picking something you can stick to for a period of time. Is there ever a case for someone saying, "Look, I like to eat low carb or even keto for six months and then switch to a more standard omnivore, caloric maintenance type diet, and then switch back"? Is there any downside to doing that for sake of health or, or weight loss over time? Or weight maintenance over time? 'Cause I realize not everyone is trying to lose weight, um, and I definitely wanna talk about at some point how to eat to maintain weight.

    2. LNLayne Norton1:04:00

       Yeah.

    3. AHAndrew Huberman1:04:00

       'Cause I think there are a significant, um, fraction of people out there who are trying to do that. But yeah, is there anything, um, i- uh, is there any downside to being a dabbler? You know, keto for a few months and then, uh, omnivore for a few months, et cetera?

    4. LNLayne Norton1:04:14

       I think that's actually, uh, a great thing, especially to, like, maybe find what you feel is easiest for you, right? Um, but in terms of, like, as a strategy, I mean, I guess, you know, some people, uh, this might get into dopamine, but, like, oh, change and get something new and, like, you know, you feel a bit more positive about it.

    5. AHAndrew Huberman1:04:31

       The new partner model.

    6. LNLayne Norton1:04:32

       Yeah, yeah, yeah.

    7. AHAndrew Huberman1:04:33

       Right, right.

    8. LNLayne Norton1:04:33

       Exactly.

    9. AHAndrew Huberman1:04:33

       Exactly.

    10. LNLayne Norton1:04:33

        So I don't think it's how I would usually set things up initially for somebody, but if somebody said, "Hey, I'd just like to have some variety and, and change it up," as long as they're still, like, you know, their behaviors and they're doing portion control or whatever it is, and they're able to sustain a calorie deficit or, you know, depending on whatever their goal is, I don't think there's really any downside to it. I, I do think the one thing to keep in mind is when you look at, like, going between extremes, so, like, um, low fat to low carb or, or vice versa, um, there can be in that transition period a little bit of weirdness for lack of a better term. Like, for example, if you've been on a ketogenic diet and all of a sudden you move to, like, a higher carb diet, you'll be, like, basically insulin resistant for, uh, just a short period of time. Now, is that gonna cause any health problems? Probably not in the long term, as l- as l- especially if you're still controlling calories. But just because your body has kind of, like, upregulated these systems dealing most w- mostly with fat and glucose production rather than glucose metabolism, so now if you start taking glucose or carbohydrate back in, like, for example, you give somebody an, uh, or a glucose tolerance test after they've been on keto, they'll do pretty terribly at it. Uh, but that doesn't last that long.

    11. AHAndrew Huberman1:05:50

        About how long?

    12. LNLayne Norton1:05:52

        Few weeks.

    13. AHAndrew Huberman1:05:53

        I think that's, uh, important for people to know because I have a feeling during those first few weeks are the period of time when a lot of people go running back to what they were doing previously, which is not to say that they shouldn't, but, um, I've certainly done that. I try- I've tried, um, very low carbohydrate diet and I would have assumed, and now I know I'm completely wrong, but I assumed-

    14. LNLayne Norton1:06:12

        (laughs) .

    15. AHAndrew Huberman1:06:13

        ... that I was so carbohydrate starved for so long that my insulin sensitivity, which is a good thing by the way folks, uh, would have gone through the roof, and I would be able to just sponge up every bit of glucose that I would have ingested through carbohydrate. So I did indeed switch over and I felt like I had pretty terrible brain fog. I even got some jitters and I thought, "Wait, what is this?" You know, my blood sugar was low before. Now my blood sugar should be in more moderate territory. But based on what you just said, I'd upregulated the...... enzymes and systems in the body for fat metabolism on the keto diet and then switching over. Um, there was a, basically a ramping up of the, of the, the, the molecules involved in, uh, presumably in glycolysis.

    16. LNLayne Norton1:06:53

        Transition period. I mean, think about like if you haven't weight trained before and you start weight training, you're gonna feel pretty terrible, right? Like, you're gonna be sore and stiff and all that kind of stuff. But I will say, you aren't necessarily wrong in what you said about being more insulin sensitive, because it depends on how you measure insulin sensitivity. So if you measure with something like, um, you know, fasting blood glucose or fasting insulin or even HOMA-IR, those tend to be pretty good on low carb. But then if you do an oral glucose tolerance test, it tends to be pretty bad. And so it, it depends on your specific measure, right? Um, so I, I think that, you know, the idea that keto makes you, you know, glucose intolerant or insulin resistant, I think, again, it's just a transition period. And I'm not too worried about it. But it is something important to keep in mind. And one of the reasons, like if somebody was to transition out of keto, typically if like I'm working with them or one of our coaches are working with them, we'll kind of instruct them to do it like slowly and kind of systematically over like a four to eight week period. That way hopefully, you know, they're not having that period of two weeks where they're like, "Oh man, why, why do I feel so terrible?"

    17. AHAndrew Huberman1:08:02

        Very important point.

14. 1:08:03 – 1:16:23

    Gut Health & Appetite

    1. AHAndrew Huberman1:08:03

       I want to go to the other end, um, literally and figuratively, and talk about gut health.

    2. LNLayne Norton1:08:09

       Mm-hmm.

    3. AHAndrew Huberman1:08:10

       Because, uh, up until now, and certainly-

    4. LNLayne Norton1:08:12

       I see what you did with that pun.

    5. AHAndrew Huberman1:08:13

       (laughs) And certainly in the last, um, few minutes, we've been talking a lot about sort of top down processes. You know, the, the brain, the psychology, placebo effects, but the very real aspects of those. Not that I can imagine 2,000 calories is 1,000 calories and somehow change the law of thermodynamics. Can't do that. But we've been sort of top down in integrating a lot of different ideas into weight loss maintenance and, and weight gain. But gut health, at least the, the more popular studies on gut health, have kind of blown a lot of things out of the water. For instance, this idea that you could take obese mice and li- literally give them fecal transplants from lean mice, and yes that sounds like what it sounds like, um-

    6. LNLayne Norton1:08:56

       Right.

    7. AHAndrew Huberman1:08:56

       ... uh, fecal transplants definitely, um, inserted through the same end in which it comes out. And I point that out because a lot of people ask me, th- they, you know, and it was kind of scary to me. I thought, "Yes, y- you know, this is not about ingesting feces. This is they-"

    8. LNLayne Norton1:09:08

       Oh. (laughs)

    9. AHAndrew Huberman1:09:08

       "... they, they literally do a, a transplant of feces from lean mice into obese mice, and the obese mice get lean." And yes, this has been done in humans, limited number of studies, and observed, um, some pretty impressive effects on weight loss that I have to assume could be related to placebo effect. They might have told these obese people, "Hey, look, you're gonna get lean through this fecal transplant from lean people." But more likely, it had some effect on their core physiology. I don't know which aspects, although I can speculate which ones. And they became leaner. They lost weight. And that is, in some sense, miraculous, when y- especially given the important role of psychology and exercise and satiety signals, because I'm going to assume that they controlled for a number of those other variables, although no study is perfect.

    10. LNLayne Norton1:09:55

        Right.

    11. AHAndrew Huberman1:09:55

        What are your thoughts about gut health as it relates to metabolism, energy utilization, and balance?

    12. LNLayne Norton1:10:02

        Yeah. So the first thing I'll say is I'm not a gut he- gut health expert, but I will, I feel relatively comfortable talking about it based on conversations I've had with people who are experts, uh, one being, um, Suzanne Devkota, who's, um-

    13. AHAndrew Huberman1:10:16

        Oh, yeah.

    14. LNLayne Norton1:10:16

        ... uh, are you familiar with her?

    15. AHAndrew Huberman1:10:17

        I, well, she's sort of a phenom in this area, from what I understand.

    16. LNLayne Norton1:10:20

        Yeah. So she was actually doing-

    17. AHAndrew Huberman1:10:21

        Yeah.

    18. LNLayne Norton1:10:21

        ... her master's when I was doing my PhD in Lehmann's lab. So she was one of my lab mates.

    19. AHAndrew Huberman1:10:24

        Terrific.

    20. LNLayne Norton1:10:25

        Um, and, you know, I, I, the other thing to say is, even gut health experts, and Suzanne will tell you this, they're like, "You know, talk to me in 20 years. We, we just know so little." And I, I think that's an overall thing that people don't understand is the scientific consensus moves very, very slow. And probably for good reason, because if we just flipped our scientific consensus based on one study, I mean, you, it would be a mess, right? So it's gonna take time before we really understand the implications of the gut and what it means. So when it comes to weight loss, there probably is a role in there. I mean, we've seen that there's something going on. Now, whether that's, is it, um, something where a gut bac- microbiome makeup that's more obese resistant, uh, perhaps it extracts less calories out of the food you eat, right? Or perhaps it's elevating BMR, although I, I think that that's probably somewhat unlikely.

    21. AHAndrew Huberman1:11:34

        Do you think it could impact the way satiety signals are-

    22. LNLayne Norton1:11:37

        So that's, that-

    23. AHAndrew Huberman1:11:38

        ... I mean, back to the brain again is my question.

    24. LNLayne Norton1:11:39

        So that's, we know that there's a link in the, the gut-brain axis, and so my suspicion is that it probably is, uh, working via appetite regulation. So tha- I mean, if we look at, um, if we look at the most effective, um, obesity treatments out there, which is like semaglutide, uh, I mean, you consistently see a, you know, 15%, you know, on average loss of body weight, which is massive, and people keep it off. Um, that is a GLP-1 mimetic, which is a gut hormone, and it basically just is a very, very powerful appetite suppressant.

    25. AHAndrew Huberman1:12:16

        Uh, uh, not, well, I guess I'm interrupting but hopefully with a purpose, um-

    26. LNLayne Norton1:12:19

        Go ahead.

    27. AHAndrew Huberman1:12:20

        ... there's this really interesting study, and it's in mice admittedly, but, uh, published in a neuroscience journal recently, and the, basically the takeaway is that like so many things in neuroscience, it, the GLP-1 works in two parallel pathways. In the brain it seems to impact neurons in the hypothalamus that control satiety, so exactly what you're saying.... and in the gut, it seems to create a, um, the, an activation of the mechanosensors in the gut.

    28. LNLayne Norton1:12:43

        Mm-hmm.

    29. AHAndrew Huberman1:12:44

        So the perception is that the gut is full-

    30. LNLayne Norton1:12:47

        Mm-hmm.
15. 1:16:23 – 1:23:59

    Tool: Supporting Gut Health, Fiber & Longevity

    1. AHAndrew Huberman1:16:23

       anything specifically to support your gut microbiome? Are you a-

    2. LNLayne Norton1:16:26

       Mm-hmm.

    3. AHAndrew Huberman1:16:26

       ... probiotic guy or a fermented foods guy or a fiber guy?

    4. LNLayne Norton1:16:30

       So again, I'm gonna kind of go straight down the line from what I've heard from Suzanne and other experts. So if you want to improve gut health, one of the biggest levers, the three biggest levers you can pull is not eating too many calories, exercising, there's a, there is a connection between exercise and the gut, and fiber. So we, it is, of the things we know, dietary fiber seems to positively impact the gut, because it is a what's called a prebiotic. So your gut microbiota can take especially soluble fiber, although there's actually some evidence, at least in mice, that they, it might be able to use some insoluble fiber as well. Uh, I think Suzanne was doing a study looking at hemicellulose and actually seeing that some, like, specific forms of microbiota flourish with hemicellulose, suggesting that they may actually be getting some kind of fuel out of it, which is really interesting. Uh, again, in mice. So, you know, just huge caveat. So your gut microbiome can produce these short chain fatty acids from, uh, by fermenting, uh, this, this, this soluble fiber, and there's quite a bit of evidence that these volatile fatty acids, which can be then actually, uh, reabsorbed in through the liver, that they have some positive effects. Um, like for example, butyrate, when they've done butyrate supplementation, they've actually seen positive effects on insulin sensitivity. So what we seem to understand is that more diversity seems to be better, fiber seems to be positive, prebiotics seem to work much better than probiotics.

Episode duration: 3:49:34