Use These FASTING SECRETS To Lose Weight & Prevent CANCER! | Jason Fung & Lewis Howes

1. 0:00 – 5:54

   What Causes Cancer: Smoking, Diet, and Obesity

   1. JFDr. Jason Fung0:00

      The secret to managing all of these things is not more medicine and surgery, it's less. It's actually within our grasp because fasting is free to every single person on Earth.

   2. LHLewis Howes0:13

      [upbeat music] I think you gotta have a dream.

   3. SPSpeaker0:14

      The School of Greatness.

   4. LHLewis Howes0:15

      Really? [laughs] Yeah.

   5. SPSpeaker0:17

      Please welcome Lewis Howes.

   6. LHLewis Howes0:19

      Welcome everyone to the School of Greatness Podcast. Very excited about our guest today. His name is Jason Fung. Dr. Jason Fung is a, is a physician, author, researcher, and he's got groundbreaking science with a number of his books about diabetes, obesity, uh, and fasting. He's got a book called The Diabetes Code, The Obesity Code, and The Complete Guide to Fasting. Sold of millions, millions of copies sold. And you've got a new book out called The Cancer Code, which I'm very excited to talk about, The Cancer Code. And I wanted to start with a question to ask you, what are the main causes of cancer? As it seems like you hear about it more and more recently that so many people are getting cancer or, um, the early stages of cancer. What are the main causes of cancer?

   7. JFDr. Jason Fung1:05

      Yeah, that's a great question, and that's something that we've always been trying to deal with. And sometimes some people say, "Well, we don't know what causes cancer." That's sort of a cop-out because we actually do know a lot about what causes cancer, and these are things that, uh, cause cancer are called, are, are called carcinogens, and the World Health Organization maintains a huge list of these carcinogens. But if you wanna break it down into what causes cancer in, uh, most people, you can look at the sort of, uh... a couple of studies have looked at the sort of percentage contribution of these carcinogens to, um, to, uh, cancer. And the mo- the biggest one of course is tobacco smoke, so that's sort of by far and away the, the biggest contributor to cancer at around 35%, and these estimates were from-

   8. LHLewis Howes1:52

      Hm

   9. JFDr. Jason Fung1:52

      ... 2015. So i- it's, i- it was higher before when more people are smoking. But as a contributor to cancer, it, it's the biggest. Interestingly, the second biggest, and almost as big, is actually our diet. So it's a huge, huge part of what contributes to cancer in general, and far outstrips those two are way above any other causes of cancer. So when you worry about things such as radiation or, you know, chemicals, sunscreens and pesticides and stuff like that, they do cause cancer, but the contri- contribution in a whole population is very small. So what's interesting about diet is that we s- we, we know this from our studies, but what part of the diet actually contributes to cancer? And that's where things sort of bog down a lot. So initially in the '70s, people talked about fiber. So people thought about, "Oh, hey, well, you know, maybe if you eat a lot of fiber, what you're gonna do is have a lot of big bowel movements, and that's gonna clean out your bowel and then you're not gonna get cancer." Turns out that wasn't true.

   10. LHLewis Howes3:05

       Hm.

   11. JFDr. Jason Fung3:05

       Then the next thought was, "Hey, maybe it's dietary fat." So if you remember the '80s and '90s-

   12. LHLewis Howes3:11

       Yes

   13. JFDr. Jason Fung3:11

       ... there's this huge movement against fat that, you know, all fat is bad for you. It caused, uh, heart disease and all this sort of stuff. Much of which has sort of, um, been, you know, overturned at this point.

   14. LHLewis Howes3:23

       Mm-hmm.

   15. JFDr. Jason Fung3:24

       But there's this thought maybe it causes cancer too. Turns out that wasn't true either. [laughs] Um, then people talked about vitamins, so maybe cancer is like a vitamin deficiency.

   16. LHLewis Howes3:33

       Mm-hmm.

   17. JFDr. Jason Fung3:33

       So we did many, many studies, millions of dollars, decades of research, where we would randomize people to, say, one group that took a certain vitamin and one group that didn't, and see if there's any difference in cancer. So we tested vitamin A, didn't work. Vitamin D, B, didn't work. Folic acid, didn't work. Vitamin C, didn't work. Vitamin D, didn't work. [laughs] Vitamin E, didn't work. Selenium, didn't work. Uh, omega three fatty acids didn't work. So all of those supplements didn't actually make any difference to the in- incidence of cancer. Uh, and the, the... so we were sort of stuck at that point in the mid 2000s saying, "Oh, we know it's the diet, but what part of the diet?" And that's when it became sort of more and more clear that this cancer is actually an obesity-related disease.

   18. LHLewis Howes4:24

       Hm.

   19. JFDr. Jason Fung4:24

       So what happened, of course, is that in the '70s, '80s and '90s, people didn't really think about it, but then we had this obesity epidemic, so it became a bigger and bigger problem. So, uh, obesity in, in 2003 when they started to look at the studies, that was the first really definitive studies that said, "Hey, you know, obesity is actually a huge risk factor as well as type 2 diabetes." And, and both of those conditions will actually increase your risk of certain types of cancer a lot.

   20. LHLewis Howes4:52

       Hm.

   21. JFDr. Jason Fung4:53

       So it really depends on what type of cancer you're talking. Like, if you're talking lung cancer, obesity plays almost no role in it, right? That's smoking. Uh, or if you have asbestos, which causes me- mesothelioma, which is a cancer of the lining of the lung, again, obesity plays no role. But things like breast cancer and colorectal cancer, which are sort of really important, uh, cancers, they actually are obesity-related cancers. So that was the sort of big link and, uh, to this, you know, at this point, the World Health Organization considers 13 different types of cancer as obesity-related cancers, which is huge because from 2003 we didn't even know. Like, when I went to medical school, nobody [laughs] thought obesity caused cancer.

   22. LHLewis Howes5:37

       Really?

   23. JFDr. Jason Fung5:38

       It's as, almost as big as smoking. It's a huge, huge thing. So therefore, if you know that, that's super powerful because if you can maintain a normal weight, you're going to reduce, just like stopping smoking, right? You're going to reduce your risk of these types of cancer.

2. 5:54 – 13:02

   Genetics, the Seed-and-Soil Idea, and Why Cancer Is a Mystery

   1. LHLewis Howes5:54

      But aren't there a lot of healthy people out there, or non-obese people that also get cancer?

   2. JFDr. Jason Fung6:00

      Oh, absolutely, because there's a lot of different things that go on, and that's what I spend the first half of the book talking about is how the sort of, uh, cancers develop. So it's not just-

   3. LHLewis Howes6:10

      Mm

   4. JFDr. Jason Fung6:10

      ... about obesity. Just like you can smoke forever and not get lung cancer.

   5. LHLewis Howes6:14

      Right.

   6. JFDr. Jason Fung6:14

      But it raises your risk. So same as-

   7. LHLewis Howes6:16

      What, what, what are the other factors? If you're, say you're h- there's people out there that are super healthy, they're working out, they're eating well, but then they get cancer.

   8. JFDr. Jason Fung6:24

      Yeah.

   9. LHLewis Howes6:24

      They're-

   10. JFDr. Jason Fung6:25

       Yeah

   11. LHLewis Howes6:25

       ... under 15% body fat, 12% body fat. What are those other factors of people getting cancer? Main, main factors.

   12. JFDr. Jason Fung6:33

       They're actually... Yeah, the, the, the rest of it we actually know very little about, so we need to know more about those because, uh, certain things, so smoking and diet are probably your biggest factors, and then there's a whole, there's like 100 different, uh, other risk factors for cancer. These are the other carcinogens that we talk about. But also things such as, you know, background radiation and sun exposure, you know, like if you get too much-

   13. LHLewis Howes6:58

       Mm-hmm

   14. JFDr. Jason Fung6:58

       ... sun, for example. So there's all sorts of other things, and genetics plays a role. But one of the big mistakes I think we made is that we focus so much on the genetics part of it, thinking that, well, this is sort of a random mutation that-

   15. LHLewis Howes7:10

       Mm

   16. JFDr. Jason Fung7:10

       ... causes cancer. Not r- sort of which puts the, puts the onus on sort of this random luck, uh, sort of, uh, idea that it's just bad luck, not realize-

   17. LHLewis Howes7:21

       My parents had this, my grandparents had this gene-

   18. JFDr. Jason Fung7:23

       Yeah. Yeah

   19. LHLewis Howes7:23

       ... so I have this. I'm gonna get cancer.

   20. JFDr. Jason Fung7:26

       Yeah, exactly, and some people think that that's sort of a death sentence. Like, if you take BRCA, which is a certain type of gene, for example, uh, so this is the gene that Angelina Jolie, for example, got, uh, diagnosed with. Her, her, her mom had cancer, I think, or, you know, an aunt had cancer. So she got tested and she had the gene, and people think, "Well, for sure you're going to get, uh, you know, cancer." But it turns out that if you look at the incidence of cancer, if you have BRCA, if you have that gene, in, like, you know, in the 30s and 40s and 50s, that risk of breast cancer was, like, 30% compared to sort of, like, 80% in modern-day America. So what's the difference? Even though you have the same genes, what's the difference between those two situations? And it comes down to the lifestyle. So the point about cancer is that cancer is like a seed. So if you have the genetics, you have the propensity to develop cancer, and this seed of cancer actually exists in all of our cells. And actually not just all our cells, but in all multicellular animals have that sort of seed of cancer. So what's important then is you can't do anything about the seed, but what you can do something about is the soil, which is that if you provide a fertile sort of soil for that seed to germinate, then you are going to increase your risk of developing this cancer. And cancer is not a rare disease. I mean, it affects, like, 1 in 10 of us, 1 in 8 of us, something like that. So it's something that we really have to think about as we live longer, because it is one, one of these really important things.

   21. LHLewis Howes8:59

       And it sounds like, you know, in the next 30 to 60 years, if we don't figure out how to reverse this or solve this or I guess create bad soil for the seed of cancer, um, by creating healthy, uh, habits in other ways, it seems like this is gonna accelerate. Where it was 30%, I guess 20, 30 years ago or 50 years ago, n- and now it's 80%, I guess, it's gonna be even more in, in 20 to 30 years, right?

   22. JFDr. Jason Fung9:23

       Oh, absolutely. And the, the, the trend is very clear because if you look at the, uh, you know, the, the biggest killers of Americans, it's always been heart disease and cancer. So if you go back sort of to the '70s, so 50 years ago, you look at heart disease, number one killer of Americans. That's heart attacks, strokes, that kind of thing. Cancer was a fairly distant second. But the rate of death from heart disease has been improving very, very quickly, and the rate of improvement for cancer has been improving very, very, very slowly.

   23. LHLewis Howes9:55

       Why is that?

   24. JFDr. Jason Fung9:57

       It's, it's because cancer is a very complex disease, and the way we think about cancer, we just don't know what it is. So for such a common disease, it's a total mystery why we get this cancer, because if you think about it, it doesn't make any sense for cancer to develop because it's actually part of us. That is, if you develop breast cancer or colon cancer, for example, that cancer cell was initially derived from our own natural cells. So what, why would it want to do this? [laughs] That is, if you get cancer, then the cancer grows, and then it kills you and it kills itself in the, in, in the-

   25. LHLewis Howes10:39

       It kills, yeah

   26. JFDr. Jason Fung10:39

       ... process. So why would this sort of thing ever develop? It doesn't make any sense from a sort of, uh, that, that, looking at it that way. But, uh-

   27. LHLewis Howes10:48

       'Cause most diseases wanna spread, but they wanna stay alive.

   28. JFDr. Jason Fung10:51

       Exactly.

   29. LHLewis Howes10:52

       Right?

   30. JFDr. Jason Fung10:52

       Exactly.
3. 13:02 – 16:46

   Diseases of Civilization and Foods to Cut Back

   1. LHLewis Howes13:02

      is it... Is it possible, is it possible in your mind to reverse cancer by the right diet and by fasting, which is something you talk about a lot?

   2. JFDr. Jason Fung13:10

      Oh, yeah, because the thing is that if you, like once you have the cancer it's really hard because that's sort of like, you know, if you, if you don't change the oil in your car, then your car breaks down, then you say, "Oh, I'm gonna start changing the oil in my car." Well, y- yeah, that's good, but you need, [laughs] you know, a lot more than that. It's the same thing. Once you actually develop the cancer, then it's really hard to fix from a diet standpoint. You really need the drugs that we've spent, you know, millions and billions of dollars developing over these last 30 years. But in terms of preventing cancer, there's actually no reason why you couldn't, because you can look at sort of people who live in a traditional society, for example. So you can take a look at, say, the Inuit or the American Indians sort of before, before sort of they became Westernized. And, or you can look at the African people before they were sort of assimilated into a Western culture. And interestingly, those, those, uh, peoples were actually considered, some of them were considered immune to cancer.

   3. LHLewis Howes14:08

      Really?

   4. JFDr. Jason Fung14:08

      There was so little [laughs] cancer that they thought that the Inuit, for example, or what used to be called the Eskimos, actually could not get cancer. So the university, Queens University in Kingston, Ontario, they used to send an expedition up to the Arctic Circle every year to study why these, these Inuit couldn't get cancer. Of course, as they became Westernized and started eating, you know, sugar and white flour, then they started getting all the same cancers that we did. In Africa, for example, this, this fellow by the name of Denis Burkitt, who's a sort of, uh, a missionary and, and doctor, when he got down there he's like, "Wow, in my..." He, he was like, "Look at these, the difference. The, the people who live traditionally in Africa get no cancer, no colon cancer, but the minute they transition to a Western-style civilization with their foods, with their, the, you know, the whole thing, they actually start to get cancer." You don't find cancer when, when that... So it's, it's, it was called actually a disease of civilization. So all of these diseases, obesity, diabetes, and cancer, were not found in people living traditionally. So the point is not that, you know, one is that they didn't live as long, but the point is that if you can find and understand what makes it, you know, protective from them, why this sort of soil, like we all have the seed, but the soil was different. What it is about that? If we can understand that, then you can, you can, you can reduce your risk substantially to the point where your, you know, your risk is very low. Um, again, as an example, if you take a Japanese or Chinese woman from Japan or from Shanghai and you move them to San Francisco, within a couple of generations their risk of breast cancer approximately triples.

   5. LHLewis Howes15:58

      That's crazy.

   6. JFDr. Jason Fung15:59

      So it's crazy, exactly, but that's great hope because it means that if you-

   7. LHLewis Howes16:03

      [laughs] 'Cause you can, if you know the root of it, then you can go back to a different way of living.

   8. JFDr. Jason Fung16:07

      Exactly. Because if you can... And, and remember, Shanghai and Japan and so on, they're, they're, you know, modern societies. So if you can understand what it is about the, the diet, about the lifestyle that's so important, you could actually take that woman in San Francisco and reduce her risk of breast cancer by a third. So that's very, very powerful knowledge.

   9. LHLewis Howes16:30

      So what would you say are the, the five foods we must eliminate to support us in preventing cancer? What are those five key things that you're like, "Oh-"

   10. JFDr. Jason Fung16:41

       [laughs]

   11. LHLewis Howes16:41

       "... man, if you can get rid of as much of this as possible, it's going to really support your chances"?

4. 16:46 – 26:35

   Insulin, Nutrient Sensors, and Cancer Growth

   1. JFDr. Jason Fung16:46

      Yeah, I think that's a good question, and it's, um, sort of sugar is probably one of the very, very important things that we really need to lower, because that really supports it. And it gets to how cancer develops. Uh, a lot of the refined foods, and people ta- a- a- and the most that we eat, like the, the one thing we eat more than anything else tends to be refined carbohydrates. Um, so you know, white bread and that kind of thing. That's probably the most important thing, uh, is the sugar and refined, uh, grains. Refined anything is probably bad for you. So y- you know, even if you're not talking about carbohydrates but refined, say, oils, you should eat natural oils. Like, eat, eat foods that are sort of in the natural state. And refined, uh, meats, like, um, you know, s- you know, eating bologna for example. People talk about meat all the time, but it's like there's a big difference between bologna [laughs] and, you know, grass-finished beef sort of [laughs] thing.

   2. LHLewis Howes17:44

      Yeah.

   3. JFDr. Jason Fung17:44

      It's, there's a huge difference because one is jam-packed full of chemicals and other crap, uh, and one is just beef, right? And people have been eating beef for thousands of years. So those refined foods, so refined carb, but also refined fats and refined proteins, probably those play a decent role although the evidence is lower. And then the other thing that is really important, the fifth thing that's probably very important is likely, uh, the frequency that we eat. That is, eating all the time provides that- ... sort of fertile soil. So, so to understand why this is, you have to get back to sort of how cancer develops. So you have to understand that cancer almost develops, evolves almost as a separate species from us. So when you have a, a breast cancer cell, for example, it originated from a normal breast cell. But after evolves, it, it, it grows or it doesn't grow depending on growth factors, and it's almost a separate species from us. That is, it will grow and it won't... The normal breast cell or a normal lung cell, they will do everything to s- you know, play on the team, right? So they're always supporting the body. You're part- you're a team player. Those cancer cells are not team players. Basically, they're out for themselves. They will grow.

   4. LHLewis Howes19:01

      The enemy.

   5. JFDr. Jason Fung19:01

      And [laughs]

   6. LHLewis Howes19:03

      It's the enemy coming to attack you.

   7. JFDr. Jason Fung19:04

      [laughs] That's right. It's, it's, it's like the guy who's just trying to pad his stats, you know? [laughs]

   8. LHLewis Howes19:11

      [laughs] Right.

   9. JFDr. Jason Fung19:12

      It's like, "You should have passed." It's like the, you know?

   10. LHLewis Howes19:13

       Yeah, yeah. [laughs]

   11. JFDr. Jason Fung19:15

       [laughs] But, but that's the point, that this cancer cell now is only interested in its own survival. That is, it will grow, and it will grow at the expense of its neighbor. So it will keep growing, and it will destroy everything around it. So it will move around, for example. So a breast cancer cell will move around the body.

   12. LHLewis Howes19:34

       Mm.

   13. JFDr. Jason Fung19:34

       And that's not for the good of the whole body, right? It's for the good of itself. It's trying to spread itself around. So you got to realize that the, the, the, the cancer cell responds as a foreign organism. And it sounds very strange to say, "Okay, we have this foreign organism," almost like an infection in us, but that's actually how our body sees that cancer.

   14. LHLewis Howes19:52

       Mm-hmm.

   15. JFDr. Jason Fung19:52

       That is, our, our immune system actually detects... It's a very powerful, um, you know, it, it kills stuff. But it's very powerful, so it has to be reined in, 'cause you don't want it destroying-

   16. LHLewis Howes20:05

       Right

   17. JFDr. Jason Fung20:05

       ... you know, normal parts of the body. So it recognizes certain cells as foreign and s- certain cells as self, and cancers are actually innately, uh, seen as foreign cells. So it is a foreign invader almost that has evolved from us. But during, uh, the development of this cancer, it will grow or not grow depending on growth signals. So our body has certain nutrient sensors. So nutrient sensors tells our body when food is available. So when you eat, certain f- certain hormones like insulin and mTOR will go up, and that tells our body that food is available. We should grow, right? Because you don't want your cells to grow when there's no food, right? It's just natural.

   18. LHLewis Howes20:47

       Mm-hmm.

   19. JFDr. Jason Fung20:47

       If there's no food, you got to get rid of some of those extraneous cells. So if you have, if you're eating all the time and you're always, you're always activating these nutrient sensors, you're actually telling your body, "Grow, grow, grow, grow." So if you eat six to eight times a day, you're telling your body, your cells in your body, "Grow, grow, grow, grow, grow." If you eat fewer times, like three times a day, or you do intermittent fasting, if you don't eat at all, what you're gonna do is shut down tho- those growth signals, and the s- cancer will have a diff- more difficult time to grow. So if you grow breast cancer cells in the lab, for example, you can't do it without insulin. It will actually wither up and die.

   20. LHLewis Howes21:31

       Mm.

   21. JFDr. Jason Fung21:31

       So therefore, if you know that, then you can say, "Well, if I..." And that's one of the secrets of why-

   22. LHLewis Howes21:35

       And insulin, insulin comes from eating any food, or is this only sugar? Is this-

   23. JFDr. Jason Fung21:40

       It's mostly, it's carbohydrates and protein. So, uh, you know, but the nutrient sensors come from different foods. So different foods will activate different nutrient sensors. But the point is that if you don't eat, like fasting for example, one is you're going to lower your insulin levels, which will, you know, lower the growth, overall growth signaling in our body, which is a good thing for adults. In adults, growth is not good. Generally, you, you'd stay the same size. You don't want to be growing too much because the, you know, growth, um, a high growth environment of course lets the cancer sort of grow out of control. And that was the secret to why vitamins, for example, was not a good thing, because it's basically growth. It's, it's, it supports growth of cells. And what they found in a lot of studies was when they gave people these vitamin supplements, they actually got more cancer.

   24. LHLewis Howes22:36

       Mm.

   25. JFDr. Jason Fung22:36

       They didn't get less cancer. They got more cancer. So in fact, it's just like if you spray, spread fertilizer on a empty field. You want the grass to grow, but what grows are a bunch of weeds because you've put down all this growth signaling, uh, stuff. So therefore, all you get is the weeds.

   26. LHLewis Howes22:53

       So-

   27. JFDr. Jason Fung22:53

       Same with the body

   28. LHLewis Howes22:53

       ... are, so are supplements and vitamins bad for us then?

   29. JFDr. Jason Fung22:58

       Uh, there's no, there's no evidence that it's really bad for you. When you give high doses in these studies, you do get certain ones, so folic acid for example, and beta carotene, which is a precursor to vitamin A. In those two studies, there was actually a, a suggestion that you actually get more cancer from them. Because in our current situation in North America, most of us are not vitamin deficient. Most of us actually have too much. You actually wanna slow down the growth.

   30. LHLewis Howes23:25

       Really?
5. 26:35 – 32:11

   Snack Culture and the Fed vs. Fasted State

   1. LHLewis Howes26:35

      What is- what does snacking do to our body, our brain, uh, our digestion system when we're every couple hours putting something in our mouth? What... Even if it's a-

   2. JFDr. Jason Fung26:44

      Yeah

   3. LHLewis Howes26:44

      ... few nuts or a fruit or a protein bar. Like, what is that doing to our brain and our digestive system?

   4. JFDr. Jason Fung26:52

      Yeah. And this is the big thing that I've had and, uh, you know, I talk about this in The Obesity Code, is because our body really, um, exists in sort of one of two states. You're either in the fed state or you're in the fasted state, okay? So when you're in the fed state you're eating, insulin is going up, and as insulin goes up, its job, like its normal job, is to tell your body to store those calories, okay? So you can store it as glycogen, which is sugar, or it can store it as body fat, but that's the point. So you eat lunch or dinner, there's way more calories in that meal than you can use right at that point, so you wanna store that. So when you don't eat, which is any time you don't eat is called fasting. So when you fast, that means your insulin is gonna drop, and that's the signal for your body to now start pulling those calories out of storage, right? And that's the reason you don't die in your sleep every single night is because we have the ability to hold some of those calories in storage. So in the fed state, insulin goes up, you're storing calories or body fat. In the fasted state you're not eating, your insulin's dropping, and you're using calories. So you're in one or the other. You can't do both at the same time.

   5. LHLewis Howes28:04

      Yeah.

   6. JFDr. Jason Fung28:05

      So if now you say, "Okay, I'm gonna go-

   7. LHLewis Howes28:07

      When I'm eat- when I'm eating, I'm storing. I'm not using-

   8. JFDr. Jason Fung28:11

      Yeah

   9. LHLewis Howes28:11

      ... calories, is that right?

   10. JFDr. Jason Fung28:12

       You will shut down.

   11. LHLewis Howes28:12

       Every time I eat I will store. I'm not burning-

   12. JFDr. Jason Fung28:15

       Yeah

   13. LHLewis Howes28:15

       ... body fat.

   14. JFDr. Jason Fung28:16

       You're not burning body fat, because you're putting in sugar, for example, uh, and that sugar is gonna signal that, hey, sugar's coming in. Use the sugar that's coming in.

   15. LHLewis Howes28:25

       Don't burn anything-

   16. JFDr. Jason Fung28:25

       Do not use-

   17. LHLewis Howes28:26

       ... off my body. Yeah.

   18. JFDr. Jason Fung28:27

       Exactly. Just-

   19. LHLewis Howes28:28

       Keep all sto- all that stored fat, keep it. Just keep piling it on.

   20. JFDr. Jason Fung28:31

       [laughs]

   21. LHLewis Howes28:31

       Right?

   22. JFDr. Jason Fung28:32

       Exactly. So the only way that you can actually use the body fat is to let the insulin fall and not eat. So if you are now eating constantly, so the minute you get up somebody tells you, "Oh, you have to eat. You can't skip breakfast. Blah, blah, blah, blah, blah," and then you have to snack all day long. So now if you look at studies, the average duration of how long people eat for is about 14 hours and 45 minutes. That's the average. So if you start eating at 8:00 AM, you don't stop till 10:45 PM. That's on average. That's the average. [laughs]

   23. LHLewis Howes29:10

       14 hours... You mean a 14-hour span of eating from the start-

   24. JFDr. Jason Fung29:13

       Yeah

   25. LHLewis Howes29:13

       ... to finish, right? You may not be eating-

   26. JFDr. Jason Fung29:15

       Yeah

   27. LHLewis Howes29:15

       ... every moment, but you're eating-

   28. JFDr. Jason Fung29:17

       No

   29. LHLewis Howes29:17

       ... every few hours within a 14-hour window.

   30. JFDr. Jason Fung29:18

       Yeah. It takes about four hours for you to switch over into the fasted state. So the point is that before where you'd eat breakfast, lunch, dinner, and by 6:00 you're done, you know, boom, you're, you know, now you shift into using those calories, and your mom would say, "Oh, you need time to digest," right? That's what she sort of said, but the point was that you need to start using those calories that you stored up during your meal times. Um, and that was the secret, that they could stay relatively slim. But now if you're eating constantly, then you never give your body a chance to switch over into that fasted state and start using those calories. And the problem of course is that insulin stays high, which tends to keep your body storing calories. Your body... So the high insulin, for example, blocks fat burning. You can't burn-
6. 32:11 – 37:42

   Fung's Own Fasting Routine and How Long You Can Fast

   1. LHLewis Howes32:11

      What's the process for you, uh, your day-to-day life? Do you eat one meal a day, two meals a day? Do you fast every month for a day? Are you always doing intermittent fasting? Is there a downside to intermittent fasting? What's your process?

   2. JFDr. Jason Fung32:24

      Yeah, I usually do a lot of sort of, uh... I rarely eat breakfast, and I'll tell you that it didn't come... Uh, I mean, I started this in medical school, and that was mostly because I really wanted to just roll out of bed and go. Like, you know, I'd wake up s- literally, like, five minutes before I left the door. [laughs]

   3. LHLewis Howes32:42

      [laughs]

   4. JFDr. Jason Fung32:43

      You know? I brushed my teeth, put on some clothes, and rolled out the door. I was... You know, it's just a, it's just the, the way I was, right? And so I, I, I don't eat breakfast now because, again, people say, "You have to eat breakfast. You have to eat," but there's actually nothing magical about breakfast. If you don't eat breakfast, what's gonna happen? Well, my body, which is now burning fat because I've had eight hours of sleep, it's gone into sort of fat burning mode because that's the storage form of calories, or it's burning sugar, um, is just gonna keep doing it, right? There's nothing wrong with it. So, um, so a lot of times I try and confine myself to sort of an eating window of sort of six to eight hours, and then once in a while when I get very busy, I will do a 24-hour fast, which is a one meal a day, and then every so often I'll do a longer fast. And the longer fasts are actually not as bad as you might think.

   5. LHLewis Howes33:31

      Mm-hmm.

   6. JFDr. Jason Fung33:31

      But they really disrupt your schedule sort of socially. It's, it's, it's a tough one because a lot of our socialization happens at meals, so I h- often have dinner with my family, for example, and doing those longer fasts is really, really disruptive to that sort of thing, which is why when you look at traditional societies, like if you look at, say, you know, during, uh, major religions, for example, there would be a period of fasting that's sort of universal, so, you know, during-

   7. LHLewis Howes33:58

      Everyone's doing it, so no one's feeling-

   8. JFDr. Jason Fung34:00

      Exactly, because it's social-

   9. LHLewis Howes34:01

      ... stressed when they smell the food, and they're like, "Ugh."

   10. JFDr. Jason Fung34:04

       [laughs] Exactly. So if you're... I- if it's, like, Good Friday or during Lent or during Ramadan for Muslims or, you know, during Yom Kippur for Jews or whatever, everybody's fasting. So it's actually terrifically easy because you're not disrupting the sort of social fabric of your life there, whereas nowadays if you fast, and I've done this, it's just really hard to do. It's not... Physically it's not hard, but it's hard, and I do it mostly, um, you know, when I, when I've gained a bit of weight. Usually after the holidays and after a vacation I will sort of schedule a, uh, longer fast right after because I know, uh, that I can lose that weight very quickly, but that means I can enjoy myself. Like, a couple years ago I went on a cruise and really ate too much. [laughs]

   11. LHLewis Howes34:48

       [laughs]

   12. JFDr. Jason Fung34:48

       Like, just a lot. I had a lot, and I knew it, and I could feel it, and my pants were tight and stuff. So I did sort of a three or four-day fast, and I'll tell you, by the next week I was back to my normal weight. Well, that's great because a week, and but I got to enjoy the whole week prior where I really didn't look at what I was eating or how often I was eating or anything. I was like, "No, this is my vacation. I'm doing this." But at the same time I know, hey, I've got this next, you know, after this week, the week after, you know, very little to eat. And, and, and, and, and it gives you a great tool to use if you need it, right?

   13. LHLewis Howes35:23

       Yeah, it's almost like either every day don't indulge, and balance and create a schedule where you're only eating in a certain window of time, whether it be four, six, eight hours, which I'm hearing is kind of the, uh, which would be a great standard to have between four and eight hours of a feeding time. Is that right?

   14. JFDr. Jason Fung35:40

       Yeah. Yeah.

   15. LHLewis Howes35:41

       And then-

   16. JFDr. Jason Fung35:41

       I mean, if you want to lose weight. You can do very well, of course, with a sort of standard '70s style sort of 8:00 AM to 6:00 PM, which in a 14-hour fast every single night. Remember, they're doing eight, for- 12 to 14 hours, say, every single night without even thinking about it. Like, that's the secret because they don't even think about that. That's just a period of time that they're not eating, right? But now of course the, the, the, the, the traditions are different. You can eat anywhere you want. You can eat in the theater. You can eat at your desk. You can eat in a car. Like, in the '70s stuff like that didn't exist. You didn't eat in a meeting in a boardroom, for example.

   17. LHLewis Howes36:16

       Mm-hmm.

   18. JFDr. Jason Fung36:16

       Now you go to a meeting in a boardroom and this is happening.

   19. LHLewis Howes36:18

       There's food everywhere. There's donuts. There's... [laughs]

   20. JFDr. Jason Fung36:20

       Donuts and cookies, right? Somebody's ordered a plate of bagels or something like that, right?

   21. LHLewis Howes36:23

       [laughs]

   22. JFDr. Jason Fung36:24

       It's like, well, why? We're having a meeting here, right? So that's the, uh, that's the thing. So you could do very well with that kind of, you know, eight-hour eating window, for- 10-hour eating window. You can do very well with it. But if you're not doing well, then you can extend it, and that's the beauty of it. You could extend it as much as you want, right? So if you think about, uh, fasting, you could go three days, you could go five days, you could go 30 days. People do that all the time. But-

   23. LHLewis Howes36:51

       No, no food?

   24. JFDr. Jason Fung36:52

       No food, yeah.

   25. LHLewis Howes36:53

       Wow.

   26. JFDr. Jason Fung36:53

       So if you look, if you think about, um, [smacks lips] ... fasting. So, uh, the a- what the amount of energy that you need, so a pound of fat has 3,500 calories roughly. If you need about 1,800 calories, so that's for, like, a regular person, not like an athlete or somebody who's working out a lot. It takes about half a pound of fat per day.

   27. LHLewis Howes37:15

       Hmm.

   28. JFDr. Jason Fung37:16

       So if you're dealing with a lot of obese people, like 100 pounds overweight, you could go 200 days. You know, if you wanna lose 100 pounds, you could go 200 days without eating before you get into trouble.

   29. LHLewis Howes37:27

       And, and survive.

   30. JFDr. Jason Fung37:27

       And survive, exactly.
7. 37:42 – 47:40

   Myths: Muscle Loss, Starvation Mode, and Mental Clarity

   1. JFDr. Jason Fung37:42

      it.

   2. LHLewis Howes37:42

      Does, does it affect your digestive system? Does it mess with your metabolism if you don't eat after a certain amount of time?

   3. JFDr. Jason Fung37:48

      Yeah.

   4. LHLewis Howes37:48

      And, and what happens when you start eating again? Does that affect your, again, your stomach, your intestines, your colon-

   5. JFDr. Jason Fung37:55

      Yeah

   6. LHLewis Howes37:55

      ... your metabolism?

   7. JFDr. Jason Fung37:56

      Yeah.

   8. LHLewis Howes37:56

      What, what's affected there?

   9. JFDr. Jason Fung37:57

      And this is the interesting part, is that everybody thinks that fasting's, like, the worst thing you could do. When you actually look at the science of what happens during fasting, it's actually one of the best things you can do for yourself, from both a mental standpoint and a physiologic standpoint. Assuming, of course, you're not malnourished, right? I mean, I'm assuming if you're the average American who's, you know, 10, 20, 30 pounds overweight, um, then this is something that actually has a lot of benefits. So there's a lot of sort of myths around it. One is that you're gonna burn a lot of muscle, and the, the truth is that you don't. I mean, when you... Y- you know, if your body, your body stores energy as body fat. So people say, "Oh, you're gonna burn muscle." It's like, well, you've got to think that our body is so stupid that it stores energy as fat, but the minute you need it, it starts burning muscle, right? Like, why would our body be so stupid? And if it were so stupid, how did we survive, right? And it's like, you know, if you save firewood all win- for the winter, and then as soon as it gets cold, you chop up your sofa and throw it into the fire. It's like, why would you be so stupid, [laughs] right? Our body's just the same. It's not that. So you know and I know and everybody knows that the way that you build muscle is that you exercise, right? So if you have, uh, you know, lift heavy weights, then your muscles become stronger. It doesn't become stronger because you eat, right? That thing does nothing for building muscle. Like, otherwise we'd be, you know, the strongest nation on Earth, [laughs] right? But we're not. We're the fattest nation on Earth. So that's the whole problem, right? I mean, you're confusing two completely different things. Um, there is a point during fasting where there is a little bit of protein breakdown, and that's where people get very confused and say, "Well, you're burning muscle." But you're not. Protein is not the same as muscle. So our body has all kinds of protein, including all the connective tissue, like the skin and stuff that holds stuff in place, and some of that is often burned off. So for example, when you look at those shows where people get surgery and they lose 150 pounds, they get all this flappy skin. That's not excess fat. That's excess protein.

   10. LHLewis Howes40:01

       Hmm.

   11. JFDr. Jason Fung40:01

       So that's, you know, it's functional tissue that you've never used up. So we actually see very little of that problem when people fast, because there's a small period of time where they're actually using up the protein.

   12. LHLewis Howes40:12

       Hmm.

   13. JFDr. Jason Fung40:12

       Your body will maintain its musculature based on what exercise and stuff you're using. Um, so another big myth, so muscle burning is one thing. The other big, big myth is people talk about is, uh, starvation mode or metabolic rate. So metabolic rate is the amount of energy that your body uses in a day, the number of calories you burn in a day. And this is what we see if you simply cut calories. So this is the standard medical advice. Cut 500 calories a day, and you'll lose a pound of fat a week. What happens, of course, is that you cut 500 calories a day, uh, and then your body quickly reduces the amount of calories it uses by about 500 calories.

   14. LHLewis Howes40:51

       Hmm.

   15. JFDr. Jason Fung40:51

       So now you're actually not losing any weight. That's what happens all the time. Because your body-

   16. LHLewis Howes40:56

       Why, why does it stop, why does it stop burning those calories?

   17. JFDr. Jason Fung40:59

       Well, it stops burning the calories by reducing its metabolic rate. So the metabolic rate is the energy that your body uses to, say, generate body heat, your liver, your kidney, your heart, and so on. And we've known this for 100 years, that if you simply restrict the number of calories but keep the foods very similar, um, what happens is that your body is going to start using less. So because it doesn't like running a deficit, right?

   18. LHLewis Howes41:24

       Hmm.

   19. JFDr. Jason Fung41:24

       It's just like if you normally make $100,000 a year and you spend $100,000 a year, now you make 50,000, you don't keep spending 100, right? It's, it's-

   20. LHLewis Howes41:33

       Hmm

   21. JFDr. Jason Fung41:33

       ... you're gonna, you're gonna get thrown into jail. [laughs]

   22. LHLewis Howes41:36

       Right. [laughs]

   23. JFDr. Jason Fung41:37

       But, but so you reduce your expenditure. Same as the body. So it's getting less, so it's gonna use less, and that's the natural reaction. It's, it's, it's important because it's a survival response. It cannot do anything different. The difference though-

   24. LHLewis Howes41:49

       So it's almost like, so it's almost like you need to be extreme in your usage-

   25. JFDr. Jason Fung41:54

       Yeah. Yeah

   26. LHLewis Howes41:55

       ... in order for it to burn and kill off these cells that might be harmful to you. But if you just do a little bit, "I'm gonna eat a little bit less today," it's not gonna do that much.

   27. JFDr. Jason Fung42:04

       Yeah. It doesn't work. And, and people assume that if you go to zero, which is fasting, say you fast for a full day, you have zero calories, you don't die, right? Because what happens is completely different. Now you've lowered your instance. You're changing the hormonal profile of the body. And as you do that, you're now switching fuel sources. So instead of using food as your fuel, you're switching it into body fat. Just like those hybrid cars where you go from gas to electric, right? So it's using food, and then boom, it's goes, "Okay, I have no food coming in. I need to switch over now into body fat." And then it goes, "Whoa, I have, like, 500,000 calories of body [laughs] fat here, so why do I need to cut, cut it down?" And the point is that it doesn't, because assuming... If you have no body fat, of course it's a problem. But for people who have adequate stores of body fat, which is most of us, and truthfully, most people do it for weight loss, too much body fat, then what happens is that there's so much there- Why wouldn't you use it? Because it's a fuel source. That's all it is.

   28. LHLewis Howes43:07

       Mm-hmm.

   29. JFDr. Jason Fung43:07

       That's the way you have to look at the body fat. If you're eating all the time, you can never use your body fat because your, your insulin's here, your insulin's high, you're using food. Then you get hungry, so you eat some more, right? You have a snack, you have a low-fat muffin. You stay here. There's... You can only burn food. All that stuff over there, those 500,000 calories of body fat are completely inaccessible for your body. So if you simply dial it down like this and say, "Okay, instead of 2,000 calories, I'm gonna eat 1,500, but I'm gonna eat 10 times a day, keeping myself here," now you only have 1,500 coming in. You can only burn 1,500.

   30. LHLewis Howes43:45

       Mm-hmm.
8. 47:40 – 55:10

   Managing Hunger and Making Fasting Doable

   1. LHLewis Howes47:40

      But isn't there a fa- isn't there, like, a period of time in the day for most people where they feel, "Man, I'm really hungry. Like, I can't focus. I can't concentrate 'cause-

   2. JFDr. Jason Fung47:50

      [laughs]

   3. LHLewis Howes47:50

      ... I'm starving. Like, I want food now."

   4. JFDr. Jason Fung47:53

      So-

   5. LHLewis Howes47:53

      And it's, it's actually hurting them in focusing. It's almost like a window of time where you have to just deal with that period, and then it switches on into, "Okay, I'm not hungry anymore."

   6. JFDr. Jason Fung48:02

      [laughs]

   7. LHLewis Howes48:03

      "I haven't eaten in a day, but I'm not hungry anymore and I'm focused."

   8. JFDr. Jason Fung48:06

      Yeah.

   9. LHLewis Howes48:06

      Isn't there this kind of window of time?

   10. JFDr. Jason Fung48:08

       There, there absolutely is. So this is why it's important to get, you know, to understand what happens during fasting so you can prepare for it. So if you look at hunger during fasting, so they've done, again, studies where they fast people for 24 hours and they measure a hormone called ghrelin, which is the hunger hormone. The higher it is, the hungrier you are. So it turns out that our ghrelin peaks three times a day: breakfast, lunch, and dinner. So you get hungry at, you know, 12:00. It's lunchtime, you get hungry. So it's a learned response. The question is what happens if you don't eat?

   11. LHLewis Howes48:39

       Yes.

   12. JFDr. Jason Fung48:39

       Does hunger keep going up and up and up? It doesn't. In fact, the ghrelin actually peaks and then it just falls. If you don't eat, it will actually just fall down, and it will fall down within a couple of hours right to baseline, which means that your level of hunger at... So at 12:30, 1:00, you're hungry, no question about it. If you don't eat, by 3:00, 4:00, that hunger level is actually the same whether you ate or you didn't eat What happened? Well, your body simply took the calories it needed from your body fat. You took that meal from your body fat and your hunger went down. So that's really interesting. So if you know that it's a wave, right? You just have to let the sort of wave pass over you.

   13. LHLewis Howes49:21

       Yeah.

   14. JFDr. Jason Fung49:21

       So I often tell people, "You will get hungry, okay? Don't, don't pretend that you're not because you will." What you gotta do is prepare for it and say, "Okay, well, if you get hungry, then you either..." There's several things. One, stay busy. You know, keep doing stuff. Don't just think about how hungry you are. So we all have had this where we're, you know, working on some kind of, you know, doing work at work or if you're doing some kind of, you know, home renovation or something. I get this all the time where I'm, like, painting, you know, the house or something like that, right? And I'll just power right through because I just wanna get it done, and I'm not hungry at all because I'm so busy. I'm so focused on doing the work that I just forgot about it, right? You see this all the time, you know, people who, who go to the casino and people who play video games. They just get so engrossed. So that's one strategy. The other strategy is to get something like green tea or coffee that you can drink. By the time you finish, you know, a big cup of green tea, the hunger will have passed, but you know that it's gonna pass, and that's the point. You know it's not gonna get worse and worse and worse and, and, and that's how you do it. What's even more interesting actually is if you look at multiple day studies where they fast people for three, four, five days, the ghrelin peaks and then after about two days it starts going down. So by, you know, day two, day three, as you get to day four, day five, the hunger almost completely disappears.

   15. LHLewis Howes50:41

       Wow.

   16. JFDr. Jason Fung50:41

       It's actually fascinating if you've never done it. So it's, I've done a few of these four or five-day fasts, and it's interesting because there's actually no physical sense of hunger. There's a whole lot of, "Hey, that slice of pizza looks really [laughs] good. I really wanna eat it."

   17. LHLewis Howes50:56

       Right. Right.

   18. JFDr. Jason Fung50:56

       But there's no actual physical hunger. So if I hadn't seen it, which is hard now of course with all the advertising and all this sort of stuff-

   19. LHLewis Howes51:03

       Mm

   20. JFDr. Jason Fung51:03

       ... I would actually, you know, gone right by and done it. But the point is that the hunger is something that you have to learn how to deal with, but it's not impossible because again, one of the big, uh, objections to people with fasting is that nobody can do it. Like, it'll work. Sure, if you don't eat you'll lose weight, but nobody will do it. Well, you know that literally millions of people throughout history have done this. Look at Ramadan, you look at Yom Kippur, you look at Lent. Like, when people say, "Okay, we're gonna fast together because our strength is in our togetherness," right? You know, "It's Good Friday. We're not gonna eat for this amount of time." Well, that's, that's how people did it, right?

   21. LHLewis Howes51:44

       Yeah.

   22. JFDr. Jason Fung51:44

       They supported each other. There was no food around. Somebody's not frying up, you know, a steak while you're trying to fast or something. [laughs]

   23. LHLewis Howes51:50

       Or baking cookies. Yeah.

   24. JFDr. Jason Fung51:51

       Yeah. [laughs] Exactly. So that's how you do it, right? You get yourself a supportive community. You know, you figure out something that you really love to do that keeps you active during that time and, and that's how you get through it, right? And, and, and while you do that, of course, your body uses up the body fats. You're gonna lose weight. It's gonna use up the, the blood sugar, which is gonna keep you from becoming diabetic. And, uh, its insulin is gonna fall which is going to reduce your risk of cancer in the long term as well as those other conditions, obesity and type 2 diabetes, which put you at such high risk of cancer in the first place. So you're doing all kinds of good stuff for your body and it's completely free, right?

   25. LHLewis Howes52:34

       You don't have to spend any money on it, yeah.

   26. JFDr. Jason Fung52:36

       Yes. Exact- [laughs] And this is the part that's crazy is because if you think about the number of diseases that you can make better, heart attacks, strokes, cancer, diabetes, which is the leading cause of blindness, of kidney disease, of amputations, the, the, the, the secret to managing all of these things is not more medicine and surgery. It's less. It's actually within our grasp because fasting is free to every single person on earth. You can do it literally right now and start right now on the path to getting better. It's just a matter of having that knowledge to do it. The people tell you, "Oh, you can't do it. You can't do it." It's like, that's not true. We all used to do it, right? [laughs] If you think about, you know, a, you know, a community of, like, you know, on Yom Kippur. Like, millions of Jews around the world are doing it. Or Ramadan, millions of, uh, Muslims are doing it or, you know, millions of Catholics are fasting during Good Friday. Like, my, my priest used to tell me all the time during Lent, you know, fasting, fast. Like, that's all he talked about practically. Um, so it's, it's, it's such an incredible tool that we've just sort of forgotten about, and yet has more power than almost anything else to prevent all of these diseases, and we don't have to charge anybody anything.

   27. LHLewis Howes53:58

       Yeah.

   28. JFDr. Jason Fung53:58

       We're not trying to sell anybody anything. We're just trying to tell you, yes, you can do it because if you have too much weight and it's putting you at risk of this cancer, then let your body burn off that sugar. Let your body burn off that fat.

   29. LHLewis Howes54:12

       A couple months ago I did a four-day fast where I just had water and a black coffee a day. Um, and it felt incredible. First couple days was challenging, but by day three I was like, "I'm in the zone." And I felt good. I looked younger. I felt healthier. Um, I was doing it for more of, like, seeing what I could do in my mindset and seeing what it would do for my, you know, kind of cleaning out my system. I just so happened to lose seven and a half pounds. It was burning a lot of excess fat. Um, but I just felt better. I felt more confident. I felt like, oh, I could do something challenging, which gave me-

   30. JFDr. Jason Fung54:55

       Yeah
9. 55:10 – 1:07:49

   Autophagy, Longevity, and the Benefits of Fasting

   1. JFDr. Jason Fung55:10

      the, the, the point about being healthier is one of these things that people think it's super unhealthy for you. It's actually one of the healthiest things you can do as long as you're, again, not underweight and you're doing it safely, right? You're not on a bunch of medications that need adjustment and that kind of thing. But there's this whole, uh, recent, um, scientific sort of revolution into this process called autophagy, which has been, uh, you know, very, very topical. People have been going crazy on it because in 2016, one of the Nobel Prizes in Medicine was awarded to one of the early researchers. And what it showed is that when you fast, uh, and you turn down these nutrient sensors, then your body actually starts to activate a process called autophagy. And autophagy, um, is where your body breaks down these sort of subcellular organelles and just gets rid of them, right? It breaks it down and recycles them. And everybody thinks, well, if you're breaking down stuff, that's bad for you, right? You're breaking down protein, it's bad for you. It's good for you because the first thing you need to do whenever you, uh, want to renovate, for example, say you want to renovate your bathroom. The first thing you gotta do is throw out everything in there, right? That avocado green tub has to go.

   2. LHLewis Howes56:24

      [laughs]

   3. JFDr. Jason Fung56:24

      Otherwise you can't put in a new tub, right?

   4. LHLewis Howes56:27

      Right.

   5. JFDr. Jason Fung56:27

      It's just the way it is. That's just... Uh, so your body works the same way. The first pr- thing you have to do is get rid of the old junky, old protein. You gotta break it down.

   6. LHLewis Howes56:38

      You gotta kill off those cells.

   7. JFDr. Jason Fung56:40

      Yeah.

   8. LHLewis Howes56:40

      You gotta destroy them-

   9. JFDr. Jason Fung56:41

      Kill off any-

   10. LHLewis Howes56:41

       ... rip them off the body and let them whatever.

   11. JFDr. Jason Fung56:44

       The stuff you don't need-

   12. LHLewis Howes56:45

       Citophagates, or they flush out your skin or whatever they do, right?

   13. JFDr. Jason Fung56:47

       Exactly. The skin proteins, the connective tissue, all of that goes. And it's not like the body knows what it needs and doesn't need. What happens is that everything starts to go, and then the stuff you need, like if you're still exercising, your body's like, "Hey, I still need those muscles. I'm gonna rebuild that."

   14. LHLewis Howes57:02

       Right.

   15. JFDr. Jason Fung57:02

       So that's the key, that one of the things that activates during, uh, fasting is actually growth hormone. So if you fast for 24 hours, your growth hormone level is, like, four times what it is-

   16. LHLewis Howes57:13

       Really?

   17. JFDr. Jason Fung57:13

       ... when you're eating. Yeah. And it sounds very strange. Why would growth hormone goes up? Well, it's because of this whole process where you wanna break down stuff. As soon as you start to eat it, you wanna rebuild all of it. So the Nobel Prize in Medicine, which is Dr. Ohsumi said this is the body's intracellular recycling system. So it's not let's flush out all our old stuff. It's not flush it out and rebuild into new stuff. But if you think about it, that's incredibly powerful because that's the whole process of rejuvenation, right?

   18. LHLewis Howes57:43

       Mm-hmm.

   19. JFDr. Jason Fung57:43

       Get rid of the old stuff, bring in new stuff. It's like renovating your body, right? So all the cells in your body undergo this process of regeneration that you're not going to get if you are eating all the time. So this is this whole, you know, in, in, in people who are very interested in wellness, a lot of people are looking into this autophagy and so on. And, and, and you get this, this point where you're doing, you know, so y- you've done these longer fasts. It's like, wow, this is... You just feel really good about [laughs] yourself, you know? You're, you're, you're full of energy, right? And, and this is the thing that I f- thought very strange when I did my first sort of three or four-day fast. It's like I have a ton of energy. Like, I could feel like I could do anything. My, my friend who used to work, uh, he's a, he's a doctor, and he worked a lot of nights and stuff. He said, "It felt like my brain was, like, on fire. Like, I thought I could do anything and everything faster than I could, and better, than I could ever do it before." Interestingly, another friend of mine who's a cardiologist, so he's a heart specialist, he says, "You know, I used to..." He played piano for his whole life, and he says, "There's always this piece that I couldn't play, and then as soon as I started fasting, I noticed that I could start to do it." [laughs]

   20. LHLewis Howes58:51

       Wow.

   21. JFDr. Jason Fung58:52

       Like, that's incredible, right? And, and, and the doctors, when I talk to the doctors, they actually, uh, instantly see the logic of what I'm talking about because they know the physiology, what happens in the human body. 'Cause what I'm talking about, which is what all the stuff we know about medical physiology, is in contrast to all the stuff that people tell you about fasting, which is, "Oh, you can't do it," and, "It's dangerous," and, "It's really bad for you." Whereas the opposite is true, right? It's actually part of a natural cycle, right? It's feeding and fasting, feeding and fasting, right? You don't feed all the time, you don't fast all the time, but we've gone so far into that one thing. So yeah, I mean, this, this whole point of, um, autophagy is very, very interesting and very topical. Uh, if you look at studies of longevity, for example, in, in animals, the only thing that really, um, makes people, makes animals in the lab live longer is caloric restriction. And so even almost 100 years ago, people were talking about it and saying, well, you can try and restrict your calories, but if you do that day after day after day, it's really hard. So fasting may be a better way to go, which is something they figured out sort of ages ago, because if you look back, that's how people thought of fasting, that people called it a cleanse, uh, a detoxification, uh, you know, reawakening, spiritual, you know, purification, that kind of thing, right? There's this whole sense of rebirth and something super healthy for you, which got turned in the '80s into something really bad for you, [laughs] right? It's strange how, how things work, but without any sort of scientific evidence, and as we've become as a nation more overweight, it become even more important. And, and, and that's just one of these sort of fascinating things. So I'm, you know, it's not like something I just made up. It's, like, literally the oldest-

   22. LHLewis Howes1:00:43

       Right

   23. JFDr. Jason Fung1:00:43

       ... dietary intervention [laughs] in the books, right? I'm just re-

   24. LHLewis Howes1:00:48

       Right

   25. JFDr. Jason Fung1:00:49

       ... ex- rediscovering this and trying to tell people, "Hey, there's a lot of good medical science that tells you this is actually something that is applicable to what we're seeing today in our healthcare."

   26. LHLewis Howes1:01:01

       Mm.

   27. JFDr. Jason Fung1:01:01

       "And you can do some... Like, you don't need your doctor. You don't need your dietician. You can do something about it right now for no money." Right?

   28. LHLewis Howes1:01:10

       [laughs]

   29. JFDr. Jason Fung1:01:11

       And there's, the science is all there, right?

   30. LHLewis Howes1:01:13

       Right.
10. 1:07:49 – 1:20:01

    Type 2 Diabetes: Causes, Damage, and Reversal

    1. LHLewis Howes1:07:49

       What is the, what is the, uh, cause of Type 2 diabetes? How does that, uh, develop in humans?

    2. JFDr. Jason Fung1:07:56

       Yeah. Type 2 diabetes is essentially, uh, too much sugar in the body. So it's not just in the blood, but it's in your whole body, right? So if you think about the body like a sugar bowl, so imagine your body is a sugar bowl. And over the years, you're sort of eating a lot of sugar. You're eating a lot more and not using it up. So the sugar sort of builds up, builds up, builds up. Eventually, it gets to the point where it starts to f- overflow.

    3. LHLewis Howes1:08:22

       Mm-hmm.

    4. JFDr. Jason Fung1:08:22

       And that's basically what Type 2 diabetes is. You've, you've stored up so much sugar in your body that it overflows into the blood. As the blood sugar goes up, then you get diagnosed with Type 2 diabetes. Now, the point is that if you look at standard medications, so some of the newer ones are quite good, but the older medications like insulin and so on, what that, what those drugs did was they have this full sugar bowl that's full. Every time you eat, the sugar would go into the bowl, flow out and spill out into the blood. The blood sugar would go high. The solution to these old drugs was to take that sugar that's in the blood and simply cram it back into the body, right? You just shove it in, shove it in. And of course, there would be, right, reach a time where shoving it in didn't work and it'd still overflow. So then you'd get a second medication [laughs] and really shove it in and shove it in.

    5. LHLewis Howes1:09:07

       Oh, man. Is that what insulin does? Or, or-

    6. JFDr. Jason Fung1:09:09

       That's what insulin does. That's exactly what insulin does.

    7. LHLewis Howes1:09:10

       It pushes it back into the body.

    8. JFDr. Jason Fung1:09:12

       Yeah.

    9. LHLewis Howes1:09:12

       Wow.

    10. JFDr. Jason Fung1:09:12

        So your body has too much insulin. So remember, insulin's job is to take that sugar that you've eaten and put it into the body, and the point is that you have had too much insulin over time because you've put in so much into that bowl that it's overflowed. The solution is not to put more in, right? It's just like if you have a suitcase. Think about a suitcase. You put it in a few shirts, it's fine. Then it gets full. You can't close it, right? So the solution is not to put more and more force to push it in. The solution is to get rid of all that stuff, same as the sugar bowl. The solution is to get rid of all that sugar. So how do you do that? There's only two things you need to know, right? Don't put it in, and two, let your body burn it off. And that's it. So that's... How do you do that? One, you can use a low carbohydrate diet, and two, you can use intermittent fasting. 'Cause when you don't eat, nothing's going in and you're gonna start burning off the sugar. Um, I mean, you can think about, in an analogy, for example. Suppose you have a car and you go to the gas station three times a day and fill up on gas. Now your gas tank is full, and every time you go to pump the gas, it overflows and spills into your backseat and is now making you sick. So what should you do? Well, I'll tell you what you wouldn't do. You wouldn't go back to that gas station [laughs] three times a day. What you would do, of course, is drive that car around. Drive it, drive it, drive it until the gas tank starts to go down. Same as the body. Every time you're just putting more sugar in, putting more sugar in. So what should you do? Well, run that body without sugar for a while.

    11. LHLewis Howes1:10:44

        Hmm.

    12. JFDr. Jason Fung1:10:44

        And that's what intermittent fasting does, and that's why we were able to reverse. We, we wrote a case series about three patients who we did this, um, and we just reversed the diabetes. Like, they had 20 years of diabetes-

    13. LHLewis Howes1:10:55

        Wow

    14. JFDr. Jason Fung1:10:55

        ... and we still reversed it in them. It was insane how quickly they got better.

    15. LHLewis Howes1:10:58

        What does Type 2 diabetes do to someone? How does it affect them?

    16. JFDr. Jason Fung1:11:04

        Yeah. The Type 2 diabetes is one of the worst diseases we have. And unfortunately, Type 2 diabetes and pre-diabetes is about 50% of the American population.

    17. LHLewis Howes1:11:12

        Wow.

    18. JFDr. Jason Fung1:11:13

        Uh, yeah. It's crazy.

    19. LHLewis Howes1:11:13

        50% of the American population-

    20. JFDr. Jason Fung1:11:14

        Yeah

    21. LHLewis Howes1:11:14

        ... has Type 2 diabetes? Or-

    22. JFDr. Jason Fung1:11:16

        Or pre-diabetes.

    23. LHLewis Howes1:11:17

        Or pre-diabetes.

    24. JFDr. Jason Fung1:11:17

        Pre-diabetes is the majority. So about 10%, 10, 15% is Type 2 diabetes. About 30, 35% is, is pre-diabetes. Um, so the point is that if you, uh, put all that sugar into your body, what happens is that you can cram it in, cram it in, but then all that sugar sort of goes all over the body, and every single organ just starts to rot away. And this is the pro- this is the reason you get, like, uh, gangrene. You know, the foot goes black, the toe goes black. That's the reason why you get all kinds of infections that you don't normally get, because there's sugar everywhere. The bacteria love that, right? So you get infections that you don't see in any other diseases. You, you get, uh, you know, too much sugar. It rots away your kidneys. You get kidney disease. You get blindness because all the sugar damage to the eyes. You know, it's the leading cause of non-traumatic blindness. Um, you know, kidney disease is what I deal with a lot because the kidneys just start to sort of rot away, so you go on to dialysis, for example.

    25. LHLewis Howes1:12:15

        Hmm.

    26. JFDr. Jason Fung1:12:15

        You get heart attacks. You get strokes. So the whole gamut. And then you get cancer, of course, because of the too much insulin. Insulin is not only a nutrient sensor, it's a growth factor. So it tells your body to grow. So all of those things that are important in terms of killing people, which is heart disease, heart attacks, strokes, and cancer, is gonna be made much worse with di- Type 2 diabetes and, uh-

    27. LHLewis Howes1:12:41

        Pre-diabetes

    28. JFDr. Jason Fung1:12:41

        ... you know, and that's why it's so important to really take care of yourself.

    29. LHLewis Howes1:12:44

        If someone is listening here, h- how would they know if they have Type 2 diabetes or if they're pre-diabetic?

    30. JFDr. Jason Fung1:12:52

        Yeah, generally you have to get a blood test to do that. So you test something called the A1C. Uh, most people who are overweight, uh, are at risk of that. And, uh, the, the point is a lot of people will say that type two diabetes is sort of chronic and irreversible and progressive. It's actually a total lie. Type two diabetes is a completely reversible disease. It's simply too much sugar. You need to empty that sugar bowl. That's the whole idea, and that's how we reverse it. Taking medications is not gonna reverse your disease, because you're simply cramming more stuff-
11. 1:20:01 – 1:23:14

    Habits Over Willpower, Eating Six Times a Day, and Fruit

    1. LHLewis Howes1:20:01

       I'm curious your take on fruit. I've had many different doctors and scientists and researchers on, uh, Dr. Rhonda Patrick, Dr. Steven Gundry, uh, just recently Dr. Peter Attia, who all kind of mention that fruit may not be the best thing for us in abundance. Uh, and being very specific on when we eat fruit, how much fruit we eat because of the sugar intake that it has. What's your research show about fruit in terms of in our diet? Is it-

    2. JFDr. Jason Fung1:20:36

       I would, uh-

    3. LHLewis Howes1:20:37

       ... more beneficial, or is it more harmful in general?

    4. JFDr. Jason Fung1:20:40

       Uh, I'm sort of, I, I, I agree with them, uh, because the fruit contains fructose, which is chemically sort of the, what you get in sugar as well. So when you eat carbohydrates like bread, it's mostly glucose. When you eat fruit, it's mostly fructose. Sugar, table sugar is sort of half and half. That's where you get high fructose corn syrup as well. Um, and the fructose is fructose no matter where you get it from. So in, in, in fruit-

    5. LHLewis Howes1:21:05

       Whether it's from an organic apple or banana, it's still-

    6. JFDr. Jason Fung1:21:08

       Yeah

    7. LHLewis Howes1:21:08

       ... fructose.

    8. JFDr. Jason Fung1:21:08

       It's still fructose. So if you drink a Coke and it has high fructose corn syrup, it's still fructose, and it's some glucose, right? Which is no different than you'd get if you were to eat an apple with, you know, some rice or something. It'd be like glucose and fructose. It's the same thing. On the other hand, the, there's, there's all kinds of other things that happens with whole fruit that may mitigate some of that badness, right? And this is the whole point that I try to make is that there's a difference between added sugars and natural sugars. So if you eat an orange or an apple, yes, the fructose is the fructose, but there's a natural limit that you have. You can't just keep eating that, right? Because you can't eat, like, 10 apples at a time. You'll just feel full, and you'll just not want to, right?

    9. LHLewis Howes1:21:55

       Mm-hmm.

    10. JFDr. Jason Fung1:21:55

        That's just life. Whereas if you s- put sugar in, like, you know, a Coca-Cola, like a Big Gulp or something, you can keep drinking that thing, like the whole thing, like lots of people do. [laughs] Um, those giant things at the movie theaters, people do. They sign, sort of mindlessly sip this sweet, sweet stuff, and the amount of sugar is probably equal to like 10 apples. But the, the, the apple had all this fiber, it had all this, you know, the pulp and all this other stuff that n- naturally put a break on how much you can get. So yes, on the one hand, fructose is fructose, so I sort of agree with that. On the other hand, I sort of disagree in that I don't think that whole fruit is nearly as bad as added sugars, because there's no limit on the amount of sugar you can add to something. Like, you can always make it sweeter, you can always make it sweeter.

    11. LHLewis Howes1:22:43

        Mm-hmm.

    12. JFDr. Jason Fung1:22:44

        And you won't even, you won't ever get that sort of break, so on, on, on stopping. So I think it's a real different. There's a, there's a big difference, but I'm not a huge fan. If you're trying to lose weight, yeah, I think you do need to limit your fruit. It's still fructose. It's not the b-

    13. LHLewis Howes1:23:02

        Yeah

    14. JFDr. Jason Fung1:23:02

        ... it's not the worst thing, but it's not the best thing for you either. Um, but as a, as a sort of treat or whatever, it's probably a whole lot better than a cookie, for example-

    15. LHLewis Howes1:23:11

        Right

    16. JFDr. Jason Fung1:23:11

        ... which doesn't have those natural satiety hormones.

12. 1:23:14 – 1:37:28

    Five Foods, Athletes and Fasting, and Fasting With Junk Food

    1. LHLewis Howes1:23:14

       Curious, you're, uh, I've asked this with a few different people in this space. If you are on a, uh, a five food only diet for the rest of your life to help the quality of your life, your, the, the health of your body, your mind, and to help lengthen your life to the best of your ability, obviously. Um, if you could only eat five foods, what would those be based on your scientific research and based on what those foods would do for the body?

    2. JFDr. Jason Fung1:23:46

       Well, I think that's, uh, um... I mean, meat is probably one of the most nutritious foods there is, and I know that there's a lot of sort of debate, sort of environmental debate. There's ethical debates about ethical raising of meat and so on. But the, you know, if you were to set all that aside and just say from a nutrition standpoint, one, it's delicious, and you know that because [laughs] when you watch shows like Naked and Afraid, [laughs] like you ever see how excited they get when-

    3. LHLewis Howes1:24:17

       Right

    4. JFDr. Jason Fung1:24:17

       ... they get a fish or something?

    5. LHLewis Howes1:24:18

       Right.

    6. JFDr. Jason Fung1:24:18

       [laughs] It's insane, right? They're like, "Oh my God," right?

    7. LHLewis Howes1:24:21

       A fish. Yeah.

    8. JFDr. Jason Fung1:24:21

       [laughs] Or it'll be like a rat or something, and they'll be like, "Oh," right? It's like you don't go like, "Whoa, cauliflower," right?

    9. LHLewis Howes1:24:30

       Right. [laughs]

    10. JFDr. Jason Fung1:24:30

        Uh, even though caul- I love cauliflower, right? It's, it's a great food, but you can see that it's, it's a natural food for humans. Like, we really get that's part of the natural thing. So meat is, is, uh, you know, meat and fish and chicken for sure would be up there. And, and, you know, scientifically, of course, they're much more complete sources of protein for us-

    11. LHLewis Howes1:24:50

        Right

    12. JFDr. Jason Fung1:24:50

        ... than natural, 'cause we're an-... animal, so therefore we use animal proteins much better than we can use plant proteins. Um, so that'd probably be a base. Uh, if you c- you know, if, uh, you know, if... So you could actually survive just on meat. So people like the Inuit, for example, subsisted largely on meat.

    13. LHLewis Howes1:25:08

        Mm.

    14. JFDr. Jason Fung1:25:08

        Uh, however, if you set aside the ethical, you know, cost and so on, uh, then you might wanna y- you know, eat some other food. So there, there are some carbohydrate containing foods which can be very good too, something like beans for example. People have eaten beans for year- like, you know, millennia, like subsisted on beans and so on. So that'd be a very, again, a vegetarian source of very good protein, and can actually be quite delicious. Like, you know, people eat it in all different kinds of ways. Um, you know, for me it's, it's one of these things that is, uh, you know, one of these things that you can put on a plate that, that, that takes that sort of carbohydrate, but there's lots of fiber and all that kind of thing. You know, some other vegetables and fruits that I really enjoy, like something like avocado. It's like I love avocado. I think everybody loves avocado [laughs] honestly. So and there's so many vitamins in there-

    15. LHLewis Howes1:26:00

        Mm-hmm

    16. JFDr. Jason Fung1:26:00

        ... and so on. So, um, you know, that's, that's something... Th- those are probably the main things I could think of. Like other, other vegetables that would be well up there, so any of the above ground vegetables. Like to me I love cauliflower and broccoli. I mean, those are just foods that I could eat sort of, uh, easily. It, it's, it's one of these things if you're trying to replace a carbohydrate side dish, like if you're thinking about, "Okay, I have a bit of meat," and then, you know, in the past you might say, "Oh, I'll have a lot of potato or rice," you could easily put cauliflower or, or broccoli or something in there that just totally takes the place of one of those.

    17. LHLewis Howes1:26:35

        Yeah.

    18. JFDr. Jason Fung1:26:35

        Um, so those are some of the foods that I d- I think are, you know, I, I'd probably, I could probably do pretty well with those things. I mean, beans, I would include tofu as well, 'cause I eat a lot of tofu being, being Chinese.

    19. LHLewis Howes1:26:47

        Okay. I like those. Those are good. What about athletes and fasting? I'm an athlete. Uh, I'll m- I'll mix it up from being like a, a power sprinter type of athlete doing different basketball, uh, um, weightlifting training, things like that, to right now I'm also in marathon training 'cause I'm committed to do my first marathon in the next six months, so I'm doing longer runs. How does fasting work with someone who is working out often? It- can you do both? Do you need to limit your ability to exercise? And again, going back to would you lose muscle as an athlete if you're doing intermittent fasting or three to four-day fastings?

    20. JFDr. Jason Fung1:27:28

        Yeah, so that's a great question, and, uh, you have to sort of differentiate between sort of the weekend athlete, the one who really isn't at that super high level of competition. For those people you could probably do whatever fasting you want, because remember, the point is that you can leave it up to your body to find those sources of calories. So if you're one of these guys, works out two or three times a week and so on, plays a little bit of ball on the weekend sort of thing, um, and that's most people. You could do whatever. You could fast and then do workouts. So that's perfectly acceptable because if you don't eat, your body will simply take those calories that it needs from, from, from your body fat. There is a period of adaptation from when your body... So remember, there's two sources of fuel in the body. There's, there's sugar, glucose, and there's fat. So your body, your muscles, so your legs and so on, can use either glucose or it can use fat. In order to efficiently use fat, you have to train it to use fat, and that often takes weeks, like three, four, five weeks in order to get that. And you can do actually muscle biopsies of people who are undergoing this transition, and you can see that they start to gain the machinery that it needs to efficiently metabolize fat. So if you are eating a high carb diet, as most of us did for most of the '90s and 2000s and so on, and then all of a sudden you say, "I'm gonna fast," well, you have no more glucose. Your muscles are gonna be highly inefficient because they haven't-

    21. LHLewis Howes1:28:53

        Mm

    22. JFDr. Jason Fung1:28:53

        ... been used to using fat. So some of the top-end athletes have actually started to train themselves to use fat. So Chris Froome, for example, the Tour de France, ultra low carb. There's Zach Bitner, who's one of these ultra marathoners, 100 mile races and stuff. He uses a very low fat, sorry, low carb diet try- training his muscle. A lot of fat, so he's training his muscles to metabolize fat. So a lot of these... Dave Scott's a very, uh, sort of legendary, uh, triathlete, uh, who really, uh, talks about low f- low carb, uh, high fat nutrition. Uh, Tim Noakes, who writes a lot about that, and these are all exercise physiologists. So you could really do well with that, and fasting's really just the same. The problem with fasting, of course, in elite sort of high level athletes is that you actually need all those calories, right? [laughs]

    23. LHLewis Howes1:29:43

        Yeah.

    24. JFDr. Jason Fung1:29:44

        So you really can't get by without eating because you, y- y- you're, you're using it. You need it, right? And most people don't have enough body fat to sustain those sort of things, right? 'Cause they're in that sort of less than 10% body fat-

    25. LHLewis Howes1:29:57

        Mm-hmm

    26. JFDr. Jason Fung1:29:57

        ... not the sort of 25% that you see in the general population. So what we do there, and we've worked with a number of elite athletes, is that you have to separate what you're trying to do. So in the on season you really can't fast. It's not-

    27. LHLewis Howes1:30:11

        Can't do it

    28. JFDr. Jason Fung1:30:11

        ... it's, it's hard to do. You need too much energy, um, and your body, you know, to perform at a high level, the carbohydrates often are slightly better than fat, unless you're in one of these ultra marathon sort of endurance events in which case-

    29. LHLewis Howes1:30:26

        'Cause they-

    30. JFDr. Jason Fung1:30:26

        ... that will be a perfect time
13. 1:37:28 – 1:50:16

    Toxins, Keto, Bulletproof Coffee, and How to Fast Long-Term

    1. LHLewis Howes1:37:28

       Are there toxins stored in our fat, and if so, is that dangerous to fast if there's toxins in the fat?

    2. JFDr. Jason Fung1:37:37

       Not really. I mean, some people talk about that, and, uh, if there is, it's- it's a very minor, um, point. I mean, so I know there's this whole theory that we get fat because, you know, our fat is trying to lock away these toxins and stuff, but there's really very little data to suggest that's true. If that's true, then of course being fat is better than not being fat. That is, the skinny people should also be being exposed to these sort of toxins as well. Um, but it's not true. You can clearly see that the people who are fatter have more risk of all kinds of diseases, predominantly type 2 diabetes and cancer and heart disease.

    3. LHLewis Howes1:38:17

       What's... y- you mentioned paleo and ketogenic diet. What's the biggest myth about ketogenic diet right now? It s- seems like everyone's trying to do this or talking about it.

    4. JFDr. Jason Fung1:38:25

       Yeah, I think the ketogenic diet is a perfectly reasonable diet from a, um, scientific standpoint. That is, if you look at what it is, it's really high in fat. But not just fats. If you, you know, uh, as with anything, and I was sort of being on the beginning of this, is that we talked a lot about natural fats, like, not eating a lot of corn oil and refined vegetable oil and margarine, right? It's eating natural fats like animal fats and coconut fat and that kind of thing. So natural fats. Not going crazy on protein, and then really, really going very low on carbohydrates. And I think that that makes a lot of sense for weight loss, and that's why it's- it's become such a popular diet. And I think there's all these, there's this reaction to it that, "Oh, it's really, really unhealthy for you." I don't think there's anything inherently unhealthy for you about the keto diet. It's also not a super easy diet to follow. Um, anything that's really different from what you're used to is not easy to follow. That's not to say that you couldn't follow it, but it- it- it does, um, it does tend to get a little difficult, uh, over time because, yeah, people enjoy carbohydrates. So, um, and this is the thing is- is- is that it's- it's- there's a... you know, when you're only talking about the foods, then you have to be very, very strict on the foods as opposed to when you can say, "Okay, I can be lenient on the foods if I'm- if I'm gonna up the fasting." Like, "Well, I'll dial this down, but I'll dial this up so that I can sort of balance it," right? It gives you more flexibility to do it. But I think one of the big myths is that it's a super unhealthy diet, but it doesn't necessarily have to be. As- as it gets bigger, then you wind up attracting all these people that are trying to sell you keto bars and keto shakes, and it's like [laughs] you know. That was sort of like the, remember the paleo, uh, movement, which was all-

    5. LHLewis Howes1:40:17

       Yeah

    6. JFDr. Jason Fung1:40:17

       ... about the caveman diet, and then you get these paleo bars. I'm like, "Yes, the cavemen did not [laughs] use-

    7. LHLewis Howes1:40:23

       [laughs]

    8. JFDr. Jason Fung1:40:23

       ... the paleo bars," right? It's like, [laughs] that's not a thing. So the movement winds up getting a little bit diluted as opposed to the original sort of movement, which was a lot of natural fats. A lot of intermittent fasting was sort of built right in, because there's talking about, well, you're gonna eat until you're full, and don't eat unless you're not, you know, unless you're really hungry. So there's a lot of intermittent fasting baked into keto originally, and like I said, some of it, it gets moved out. Y- you wind up attracting all these other people who try and put their sort of spin on it and-

    9. LHLewis Howes1:40:54

       Commercialize it. Yeah, yeah.

    10. JFDr. Jason Fung1:40:56

        Yeah, yeah, commercialize it, which-

    11. LHLewis Howes1:40:57

        What about... what- what's your thought then on the bulletproof or the coffee with ghee method, uh, you know, where you fast, intermittent fast, but then you have coffee with a little bit of ghee or something like that. Is that something you feel like is useful while intermittent fasting, or is it better to just do water only and black coffee, uh, or no coffee?

    12. JFDr. Jason Fung1:41:19

        Yeah, I think that the classic is water only. Uh, coffee, like black coffee, and tea, like green tea, herbal tea, make very little difference. So even though they're not part of a classic fast, w- black coffee makes no difference. There's no calories. There's very little anything else, right? When you get to bulletproof coffee, [coughs] it's actually very interesting because it, again, the- the main point of intermittent fasting is you're trying to reduce your insulin so you're getting into the sort of fat burning. When you take pure fat, so coffee with ghee or whatever like that, you're taking almost pure fat, which is interesting because it's actually not gonna affect your insulin at all. So some people do very well on that because the, what you're trying to do, of course, is you take that bulletproof coffee, um, and then you don't eat. Like, that's the point. You're not taking it and then eating, you know-

    13. LHLewis Howes1:42:10

        Right

    14. JFDr. Jason Fung1:42:10

        ... a big muffin, right? That's not [laughs] the point of that, uh, exercise. You're taking it-

    15. LHLewis Howes1:42:13

        You're not dipping the donut in the coffee.

    16. JFDr. Jason Fung1:42:16

        [laughs] Exactly. So you're just trying to take it and then not eat, and if it allows you to not eat for a long enough period of time, 'cause some people say, "Oh yeah, I get just so full," then you're gonna be net better. So remember, when you're taking almost pure fat, you're not having any insulin effect. That fat actually goes almost straight into your fat stores, but it keeps you in that fat-burning mode. So it's sort of this thing-

    17. LHLewis Howes1:42:39

        So it's adding some fat storage, but it's burning as well.

    18. JFDr. Jason Fung1:42:43

        Exactly. So it depends on your net balance. That is if the fat that you put in allows you to fast for a long enough period that you're gonna balance it out, then you're net better. If you're gonna take a bulletproof coffee at 9:00 and then eat something at 10:00, well, you, you didn't take [laughs] you didn't buy yourself enough time with that bulletproof-

    19. LHLewis Howes1:43:03

        Yeah

    20. JFDr. Jason Fung1:43:03

        ... coffee to offset that. It's the way that the body metabolizes fat. And, and it's, it's, it's strange because it's not usual for our body. Like, we don't usually just eat a stick of butter. Like, that's not-

    21. LHLewis Howes1:43:15

        Yeah

    22. JFDr. Jason Fung1:43:15

        ... a meal, right? [laughs] So therefore, that's why this is sort of like a hack because it's sort of this thing that people do, but it has to give you enough time to-

    23. LHLewis Howes1:43:24

        Mm-hmm

    24. JFDr. Jason Fung1:43:24

        ... come up benefit, right? It's like investing, right? You have to put in money to make money, and you hope that you don't just throw it away, right?

    25. LHLewis Howes1:43:31

        Yeah.

    26. JFDr. Jason Fung1:43:31

        Same thing. You're, you're taking in calories to try and fast for long enough to burn net more-

    27. LHLewis Howes1:43:36

        Mm

    28. JFDr. Jason Fung1:43:36

        ... calories.

    29. LHLewis Howes1:43:38

        What it would be the ultimate way to do intermittent fasting in your mind? And is this something that we should do every day, intermittent fasting, or periods of time, seasons of life?

    30. JFDr. Jason Fung1:43:48

        Yeah. I- that's a great question. I think that fasting is actually a part of natural life. So if you think about fasting, people think it's some, you know, strange thing that you do, but it's really not. That's where the word breakfast comes in, right? So the meal that breaks your fast. You have to fast to break your fast. So even baked into the English language, and it's actually not just the English language. In French, it's petit dejeuner. Jeuner is the word to fast, so it's to break your fast. So the point is that you're supposed to feed and fast, so you're supposed to be at 12 to 14 hours every single day. Yeah, maybe once in a while you'll have a midnight meal or whatever, but that's for in general you should be fasting every single day. Then I think then there's occasional longer fast, and I think this is the point is to, you know, every once in a while just to sort of cleanse the system, keep things kinda going, and that's the way we did it, right? If you look at, uh, any of the major religions, you know, some did it more than others. Greek Orthodox had all kinds of fasting periods and, but, you know, and people would do it differently. When Mormons would do it differently from Catholics would do it differently from Buddhists, for example. But they all had this idea of fasting. Buddhists, for example, won't eat after 12:00 noon, so they'll just fast until the next day, so sort of a four-hour eating window every single day sort of thing. So that's, that's the way they do it. But this occasional longer fast is, I think, beneficial to sort of activate this autophagy and get the benefits of a longer fast because you're getting different things happening at different stages. If you're getting 12 to 14 hours every day, you're getting a lot of the benefits, and then every once in a while you try and get the benefits of that longer fast, and you do it at pre-specified times of the year. And religion is what used to tie people into this whole cycle, or they'd do it because it was winter, right? You'd have a big meal at Thanksgiving. After that, you know there's not a lot of food coming in, so then, you know-
14. 1:50:16 – 1:59:01

    Cold Exposure, Mindset, and Religion's Wisdom

    1. LHLewis Howes1:50:16

       It's interesting. You mentioned briefly the, uh, [smacks lips] uh, different societies that w- we found probably had very little or no cancer. I think you mentioned the, the Eskimos?

    2. JFDr. Jason Fung1:50:27

       Yes.

    3. LHLewis Howes1:50:27

       Is that what you said?

    4. JFDr. Jason Fung1:50:27

       Yeah.

    5. LHLewis Howes1:50:27

       Before, before they became Westernized, I guess, or before, um, things started to shift. It's interesting. I just did a... I've, I've done a lot of training with Wim Hof. I'm not sure if you've heard the name Wim Hof.

    6. JFDr. Jason Fung1:50:39

       Yeah.

    7. LHLewis Howes1:50:39

       He's a, he's a, a guy who focuses on breathing, on mindset, and on cold therapy exposure, uh, extreme amounts of cold therapy exposure. [smacks lips] And he has done a test, I don't know if you've heard about this, where they injected, I believe it was E. coli, into his body, and he rejected the disease from breathing and cold therapy, where-

    8. JFDr. Jason Fung1:51:04

       Wow

    9. LHLewis Howes1:51:04

       ... it actually didn't harm him, um, and he didn't contract the disease, I guess. Uh, and he did this with a, a, a group of other subjects of just people who he did the method with where it was cold therapy, breathing, uh, were they able to reject the infection. I'm curious, in your mind, about cold exposure, knowing that the Eskimos are in cold and they didn't have, uh... maybe it was all they, all they did was eat meat and in cold. How much do you think cold therapy, cold exposure supports with eliminating cancer?

    10. JFDr. Jason Fung1:51:38

        I don't know. I, I haven't really looked into that, I have to say. I don't think it's just the cold, because the, uh, the Inuit, uh, of course, when they started to eat, like they're still in the cold, but when they started to eat all kinds of processed foods like sugar and bread and stuff, they wind up getting cancer. They also see it in Africans who live a traditional African diet. Again, they really have very little cancer. So it, it was, um... [smacks lips] that was where they described these sort of diseases of civilization. So it didn't have to do just with the cold. On the other hand, I actually think there's a lot of interesting stuff, both with extreme cold and extreme heat, where people, you know, talk about the benefits of, like, saunas and all this sort of stuff, which I think is very interesting. I actually haven't looked into it a lot myself. I actually think that the extreme cold, to me, seems like it... there may be something there. Um, you know, there's actually a few things that people talk about, like the browning of white fat and all this-

    11. LHLewis Howes1:52:32

        Mm-hmm

    12. JFDr. Jason Fung1:52:32

        ... kind of stuff.

    13. LHLewis Howes1:52:33

        Mm-hmm.

    14. JFDr. Jason Fung1:52:34

        Which makes a lot of sense to me, but I, you know, seems it, it, you know... and, and there's a lot of people who do it, like in, in Scandinavia and Russian and stuff, there's all these people who do this sort of cold therapy, and they swear by it. And, and it's like I think that there probably is something there. I don't know how much it has to do with what I talk about, which is mostly, like insulin and foods-

    15. LHLewis Howes1:52:55

        Mm-hmm

    16. JFDr. Jason Fung1:52:55

        ... and fasting and so on, but I think that there's actually going... I, I think somebody should look into that, but again, with the... w- because nobody makes money on it [laughs] you know?

    17. LHLewis Howes1:53:04

        Right, right.

    18. JFDr. Jason Fung1:53:04

        It's, uh, [laughs] it's one of the things-

    19. LHLewis Howes1:53:05

        Jumping in the ice is not a money-making thing, yeah.

    20. JFDr. Jason Fung1:53:07

        Yeah, and it's not, doesn't seem so comfortable to me. But, you know, on the other hand, I actually think that there probably is something there that is highly beneficial.

    21. LHLewis Howes1:53:16

        Maybe that's your, uh, the next book down the line, The Cold Code.

    22. JFDr. Jason Fung1:53:19

        [laughs]

    23. LHLewis Howes1:53:20

        The Cold Therapy Code, to see what that does with, with cancer. Um, this has been fascinating. I feel like I have so many more questions I wanna ask you, but I also wanna be respectful of your time with this interview. This, for me, I could ask more and more about this stuff, 'cause I feel like the body, uh, is, you know, it's our temple. It's the thing we need to take care of the most, and if we wanna have a high quality of life, we need to take care of our body, and if we wanna have a longer life and be around for more memories with our friends and family, then we've gotta also take care of these things. Uh, a few final questions for you. But before I ask these final questions, is there anything else that we should be aware of when it comes to the mindset around cancer? Have you found any research on healing the mind in order to heal the body physically, or is it more been around nutrition mostly?

    24. JFDr. Jason Fung1:54:10

        Uh, most of the data is around nutrition. I think that the way it interacts is that I think that there's actually, like, a lot of those things are super important. So when people talk about positive attitudes and gratitude and community and staying connected and all that sort of stuff- It sounds hokey, but it actually has a huge impact on life and quality of life, and even longevity. But it's hard to study because how do you quantify if somebody is grateful, for example? Or if they have a positive attitude? It's very hard to quantify that, so it tends not to get studied. But I think the where it interacts is that it, if you are one of these people who has a lot of stress and very unhappy or isolated like a hermit compared to somebody who has tons of friends and goes out and, you know, has a great supportive church and all this sort of stuff, um, where I think it play, makes a big difference is that, uh, you can measure sort of stress levels, like, and there are certain things that get activated during chronic stress like cortisol, which is a certain hormone, and I think that impacts the immune system. So the immune system, which under chronic stress winds up getting degraded, right? So if you produce, if you're under too much stress, your immune system really doesn't work as well, and the immune system plays a key role in fighting cancer. So I think that there probably is some, I think there's a lot of truth to that.

    25. LHLewis Howes1:55:41

        Mm.

    26. JFDr. Jason Fung1:55:41

        But the data is hard to find, uh, because then you get all these sort of, you know, very by the book sort of doctors who say, "Well, there's no proof that having a lot of friends makes you live longer." It's like, well-

    27. LHLewis Howes1:55:55

        Right

    28. JFDr. Jason Fung1:55:55

        ... that's data. Or if you're grateful or keep a journal or whatever, or meditate, it's like, that's, it's, it's, it's not that there's not a real effect, I think, and they confuse the fact that it's very hard to study with the fact that it doesn't work. Like, I think it works. I think it's super important. I think that's actually more important than almost everything else. Like, being k- you know, being grateful, being happy, you know, being connected. I think that's actually has a bigger impact on life [laughs] than most anything else. Um, but it's so hard to, to put it into a scale where you can say, "Okay, this is this and this is this."

    29. LHLewis Howes1:56:32

        [clears throat]

    30. JFDr. Jason Fung1:56:32

        So I think it does play a role, but-
15. 1:59:01 – 2:10:33

    Resources, Three Truths, and Definition of Greatness

    1. LHLewis Howes1:59:01

       Yeah. I'm, uh, I'm so glad we've connected. I've got these couple final questions I wanna ask you that I ask everyone at the end of my show. Uh, before I ask them, I wanna remind people about, uh, all the books you have. You've got a new book called The Cancer Code: A Revolutionary New Understanding of a Medical Mystery that's out. Um, you've got a few other ones. The Obesity Code, and also The Diabetes Code, which I... And also The Complete Guide to Fasting. So you've got also thefastingmethod.com, which can help you with fasting if you need a support community, if you need tools, if you need resources. So go check out thefastingmethod.com. I believe that is correct.

    2. JFDr. Jason Fung1:59:41

       Correct.

    3. LHLewis Howes1:59:42

       And, uh, check you out on social media. You're Dr. Jason Fung on Instagram, Twitter, and Fung Style Fasting on Fa- uh, on Facebook, and thefastingmethod.com. This has been extremely insightful a- and eye-opening for me, and hopefully it's, uh, a lot of great tools for so many other people that listen to this and watch this. If you're watching, uh, online, feel free to share this. Feel free to like this up. Leave a comment below of what's supported you the most over on YouTube. This question is at the end that I, I ask people called the three truths. So I'd love for you to imagine for a moment a hypothetical scenario, Jason, where, uh, it's your last day on earth, and it's as... You get to live as old as you wanna live, but eventually you gotta turn off the lights. And you've created and accomplished and lived the exact way you wanna live. You've written many books and, and done so many different things. Uh, but for whatever reason, all the content you've put out in the world has to go with you to the next place, wherever that place is. And so no one has access to this interview or any of your content anymore. But you get to leave behind three things you know to be true from all of your lessons in life, kind of these three lessons you'd share with the world, or I call the three truths. What would you say are those three things for you?

    4. JFDr. Jason Fung2:00:56

       I think one of them is, of course, the importance of, um, intermittent fasting. Like, it's, it's really just a part of the way you're supposed to live. That is, everything is a cycle, right? Yin and yang. It's all a cycle. Feeding and fasting is that same cycle. You can't do all of one or all of the other. We've gone so far, of course, towards feeding that, you know, you really have to turn [laughs] back the dial a little bit on that side. So that's one of the sort of, uh, great things that I'd, I'd love to sort of leave with people, and I think that's what The Obesity Code was about, was like, let's really think about what causes this disease. Um, you know, the second thing is, uh, very similar to, to that. I, I, I'd love people to really understand that type 2 diabetes, uh, and that one is near and dear to me mostly because that's what I deal with a lot in my profession. As a kidney specialist, I see a lot of type 2 diabetes, so I'm always invested in it because my patients are suffering from it, and I always think it's a shame. Like, boy, I wish that people would've told you that it's reversible. Like, you don't have to suffer this disease. You can do something about it if you want. If you don't want, that's fine too. But, you know, it's a reversible disease, and that's one of the things I always think about when, you know, it's like there's so much suffering in this world that really is not necessary if people had the right understanding. And then, uh, the third thing, I think, of course, um, is to always sort of stay real, um, which is that, you know, as you get out there, like, y- you know, you know, I mean, 'cause you're in the public eye a lot, you get a lot of, you know, admirers, but you get a lot of haters as well, right?

    5. LHLewis Howes2:02:47

       Mm-hmm.

    6. JFDr. Jason Fung2:02:47

       So you always gotta stay real, and similar to, like, this whole idea of living a digital life or, you know, on social media life, you know how everybody's happy and smiley [laughs]

    7. LHLewis Howes2:02:58

       [laughs]

    8. JFDr. Jason Fung2:02:58

       That's not real life. Um, and I always think, like, stay real. Like, like, just do real things. Like, you know, it's fine to be on social media and stuff, but that doesn't mean you don't see your friends, and make sure you go out with, you know, to, to, to, to run or to play some ball or to whatever it is that you enjoy doing. You know, read. There are other things that you can do, but you have to sort of stay in the real world, right? It's like being present. You have to be there, right? Because in the end, that's what you will always remember, right?

    9. LHLewis Howes2:03:33

       Yeah.

    10. JFDr. Jason Fung2:03:33

        It's not the Facebook friends that you had or whatever. And, and, and, and it goes the other way, too, right? There's lots of Facebook friends and stuff, and they're great, but you also get those haters who are always, like, ragging on you and stuff. "Oh, you're such a phony, and you're just trying to sell out," and all this stuff. And I always think, okay, one, I wind up just blocking those [laughs] people because they're a pain to deal with. And I always think that you gotta stay real. Like, if somebody came up to me, and I get this a lot, some people say, "Oh, he's full of crap. That's... I can't believe he's a doctor" kind of thing, and I'm always like, uh, imagine going up to somebody and saying that to my face, right?

    11. LHLewis Howes2:04:06

        That's-

    12. JFDr. Jason Fung2:04:06

        You'd never do it

    13. LHLewis Howes2:04:07

        Never do it.

    14. JFDr. Jason Fung2:04:08

        And I'd never talk to you again, so why would I want you to talk to me? I'd just mute you right away, right? And that's part of staying real, right? Like, so stay doing real things. And it's so easy, especially now with COVID, where we're all supposed to be going and doing virtual things. But, you know, it's like you're not gonna remember that. Like, a virtual trip to, you know, the beach is not the same as going to the beach. I mean, you know, you gotta go to the beach, right? [laughs] And I think that that's one thing that I've been thinking about. I- maybe more during this period of time when we're not allowed to do anything.

    15. LHLewis Howes2:04:41

        For sure.

    16. JFDr. Jason Fung2:04:41

        But, you know, when it comes back around to it, it's like, remember, there are friends and, you know, there are friends and you, you can... You know, don't get down on the stuff you see online, either from, oh, people ragging on you or the fact that people are always smiling in a beautiful place on Instagram, right? It's like that's not real life either. So go out, do something real, talk to real people. It, it, it benefits you no matter, no matter what, right?

    17. LHLewis Howes2:05:06

        Yeah.

    18. JFDr. Jason Fung2:05:06

        It's, it's always better to do that, even though it's easier to sit in front of a screen and, you know, play video games or watch-

    19. LHLewis Howes2:05:14

        Yeah

    20. JFDr. Jason Fung2:05:14

        ... somebody else's life and stuff, right?

    21. LHLewis Howes2:05:16

        Love that. Those are good three truths. Uh, I wanna acknowledge you for a second, uh, Jason, for you have amazing analogies. You, you turn the complex into something that's understandable and easier to break down, which can seem very scary, very overwhelming, very hard to understand. When you're dealing with sickness, disease, illnesses, viruses, obesity, cancer, these are scary subjects, and the fact that you're able to communicate effectively the hard, uh, data and research so that everyone can understand it is extremely powerful for us. So I acknowledge you for the decades of research and work and practice in mastering this and constantly trying to learn new ways to make it better for the rest of us. I acknowledge you for that and for, uh, for being a nice doctor, for being a kind-hearted doctor.

    22. JFDr. Jason Fung2:06:05

        [laughs]

    23. LHLewis Howes2:06:05

        Uh, I appreciate that. Hopefully when you're in LA-

    24. JFDr. Jason Fung2:06:07

        Thank you

    25. LHLewis Howes2:06:07

        ... uh, we can do this in person again sometime and, um, get some more content out of this, 'cause I think this was really helpful for-

    26. JFDr. Jason Fung2:06:14

        Mm-hmm

    27. LHLewis Howes2:06:14

        ... for myself and I think for everyone listening and watching. My final question for you, Dr. Jason Fung, is what is your definition of greatness?

    28. JFDr. Jason Fung2:06:21

        I think, you know, that greatness is really about being able to impact people in a positive way, right? And I see so much of this, again, online, because of course everybody's online nowadays, right? 'Cause that's all you can do. But, and, and, and I'm sure you've seen this as well, right? It's like- Because I think this is the core of what you wanna do, is do something good for people. But there are people who get famous for putting other people down.

    29. LHLewis Howes2:06:52

        Mm.

    30. JFDr. Jason Fung2:06:52

        Right? And it's like, oh, God, like I get it. You wanna be famous for putting somebody down, whether it's people you think deserve to be or not. Like, oh, you know, people rag on this guy or that guy, and it's like, yeah, but you're just trying to build yourself up, right? The greatness is not in tearing somebody down or saying that this guy is stupid or this theory is stupid, right? It's like, you know, when I talk about calories and stuff, sometimes I get frustrated and I say, "Oh, that's really stupid," right? But that's not what I'm trying to do, right? What I'm trying to do is not just tear something down, 'cause I don't really like to do that. I like to sort of say, "This is a better way to look at it," right? "Think about it this way, because this is what's gonna make you better."

Episode duration: 2:10:33