The Science Of Protein And Longevity: Do We Need To Eat Meat To Live To 100? - Dr. Mark Hyman

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Episode 710
The Doctor's Farmacy

The Science Of Protein And Longevity: Do We Need To Eat Meat To Live To 100?

Open the Podcasts app and search for The Doctor’s Farmacy. If you’re viewing this site on your phone, you can just tap on the

Tap the subscribe button and new shows will be added to your library.

If you’re using a different device, our show is available on the following platforms.

View all Platforms

If we want to age as well as possible, maintain function and strength, and stay independent as we age, there is a key area of our physiology that we need to pay attention to: muscle.

Skeletal muscle is the currency of healthy aging; it’s an essential lever in maintaining optimal metabolic health, reducing body fat, and supporting longevity. And a major piece of building and maintaining muscle is protein consumption—which is often a controversial topic in the nutrition space.

Today on The Doctor’s Farmacy, I talk with Dr. Don Layman about the science of muscle mass, and optimal protein requirements for chronic disease prevention, performance, and longevity, and how to pay attention to these things in our daily lives. 

So many people are confused about how much protein they should be eating. Dr. Layman and I break down the right amount for optimal muscle synthesis and maintenance versus what the government’s Recommended Daily Allowance suggests, and we discuss what that looks like for each meal of the day. 

We also discuss the role protein plays when it comes to weight loss, stabilizing blood sugar, and reversing metabolic syndrome. Dr. Layman and I talk about the best sources of protein, from a muscle-centric point of view, as well as the connection between dietary protein and mTOR. I Think of mTOR as a “longevity switch” that is influenced by when and what we eat, among many other factors. 

We also talk about essential amino acids and why they are such an integral part of building lean body mass, the relationship between resistance training and protein intake, and so much more. I hope you’ll tune in.

This episode is brought to you by Rupa Health, BiOptimizers, Mitopure, and Joovv.

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I hope you enjoyed this conversation as much as I did. Wishing you health and happiness,
Mark Hyman, MD
Mark Hyman, MD

In this episode, you will learn:

  1. The early work that led Donald to muscle-centric health
  2. Protein, carbohydrates, and insulin resistance
  3. Why all calories are not equal
  4. Weight-loss research looking at high-carb, low-protein diets
  5. High percentages of women in certain age groups don’t eat enough protein
  6. How our protein needs and metabolism change with age
  7. Meeting protein needs with a vegan diet
  8. Protein quality and muscle growth
  9. Healthy aging, muscle, and MTOR
  10. How much and when should you eat protein?
    ( 1:18:07)


Mark Hyman, MD

Mark Hyman, MD is the Founder and Director of The UltraWellness Center, the Head of Strategy and Innovation of Cleveland Clinic's Center for Functional Medicine, and a 13-time New York Times Bestselling author.

If you are looking for personalized medical support, we highly recommend contacting Dr. Hyman’s UltraWellness Center in Lenox, Massachusetts today.

Dr. Donald Layman

Dr. Donald Layman is a Professor Emeritus in the Department of Food Science & Human Nutrition at the University of Illinois at Urbana-Champaign. He served on the faculty at the University of Illinois from 1977 – 2012. Dr. Layman earned his B.S. and M.S. degrees in chemistry at Illinois State University and his doctorate in human nutrition and biochemistry at the University of Minnesota. He is recognized for research on protein and amino acids for muscle health related to athletic performance, obesity, diabetes, and cardiometabolic health. Dr. Layman is also a nutrition consultant to the food industry.

Show Notes

  1. Me at age 40 vs age 60

Transcript Note: Please forgive any typos or errors in the following transcript. It was generated by a third party and has not been subsequently reviewed by our team.

Introduction: Coming up on this episode of The Doctor’s Farmacy.

Dr. Don Layman: We’re talking about middle the road sort of diets. We’re not talking about keto carnivore, we’re not talking about vegan. We’re talking about in between which people can exist at the extremes. But the average person really is going to be best off at this middle ground where they’re protein-centric, they’re protein conscious, and they keep their calories under control.

Dr. Mark Hyman: Welcome to The Doctor’s Farmacy. I’m Dr. Mark Hyman. That’s pharmacy with a place for conversations that matter. And if you’re confused about nutrition and specifically about protein, how much you should eat, what kind you should eat, is it better to be vegan, better to be a carnivore or somewhere in the middle, and this is going to be an enlightening conversation because it’s one with the world’s expert on protein, Dr. Donald Layman, who’s a professor of emeritus in the Department of Food Science and Human Nutrition at the University of Illinois, Urbana-Champaign.
He’s served on the faculty of the University of Illinois from ’77 to 2012. He’s got his BS and MS degrees in chemistry at Illinois State and a doctorate in human nutrition about chemistry at the University of Minnesota. He’s recognized for his research on protein and amino acids for muscle health. And we’re going to talk lots about muscle today. And I’m way more interested in muscle today than I ever was because I’m getting older and I come to understand that muscle is the currency of longevity and how muscle relates to athletic performance, to obesity, diabetes, cardiovascular health. And he is also a consultant in the food industry and very active helping get the word out about protein and nutrition and health. So welcome, Dr. Layman.

Dr. Don Layman: Well, thank you, Mark. It’s great to meet you and thank you for that introduction.

Dr. Mark Hyman: Well, I appreciate you joining me today. I’ve known a bunch of your students and I figured why not get it from the horse’s mouth. So here we are and I’m very interested in this topic of protein, particularly as it relates to longevity and aging and how we age better. And I know you were part of the pro age group, which looked at a lot of the literature on protein and aging and what’s optimum and what’s not and what kind of protein and when to eat protein and all these questions. And I covered in my book, Young Forever, but I really wanted to get into the deep science with you because I think so many people are confused about what to eat. Even longevity experts, many of them are vegans and think that that’s the best way to extend your life. Others are more focused on building muscle and longevity.
Like Peter Attia’s a colleague and friend of mine. So there’s this whole confusion among the scientific community, the [inaudible 00:02:38] community. So the layperson is probably sitting at a home going, well, those guys can’t agree, “What the heck am I going to do? I’m just going to eat my bagel and have a good time here.” Because they can’t get their crap together. So I’m so excited to have you talking about this. And in your career, your focus has been on muscle development, malnutrition in children at the beginning.
And I wonder how this work led to you coming up with this idea of muscle centric health because let me tell you something, Dr. Layman, as a doctor, I don’t ever remember a course on muscle other than this is this muscle, this is that muscle and anatomy. But I never really took a course on truly why muscle’s important, how you take care of muscle. I know how to take care of your heart and your liver and your kidneys, but muscle was just part of your skeleton. So who cares? As long as you have it and it’s working and it’s not damaged, then that’s fine. But you’ve really come to understand that muscle is the key to healthy aging. So can you take us through that discovery on your part of how you came to understand that and what that means?

Dr. Don Layman: Yeah. Wow. That unlocks and unfolds a whole lot. So let’s wade into it. So I got into the whole field accidentally. I grew up on a farm in Illinois, so I watched animal growth a lot. So I understood about diet and exercise and I was very interested in science. So I went off and studied biochemistry, and one of the first things I got into was studying protein synthesis, individual by the name of Arlin Richardson at Illinois State University. And he was really well known in the aging field. And what we discovered in my masters was that as we age, the process of synthesis becomes less efficient. There are things that change, our ribosomes aren’t as active. The messenger RNAs change, they don’t have the long poly-A tail. The whole process becomes less efficient. And that’s part of the aging process, and I’ll come back to that.
Then as I started going on into nutrition, I got involved with a group that had a big interest in muscle. I was sort of a pretend athlete. I was always interested in athletic performance. And so muscle was inherent to me as we started looking at malnutrition. And then I got the opportunity actually to work in Northern Africa with malnutrition. One of the things I found very quickly was with children is if they had nutrition insults really early in life, really in that first year, they would reduce the number of nuclei, the number of muscle cells that they could develop. And so they had a reduced muscle mass. And what I learned was that that was basically predestining them to obesity. So I started thinking about, wow, muscle really has a big role in body composition. And so early in my career we ran a lot of rodent studies looking at malnutrition at different ages and things like that. And we found that relationship of muscle to obesity.
And so from there, I got interested in the obesity question and clear back in the early eighties, people were looking at obesity and fat cell number and brown fat and all of that, and basically doing really interesting research that got them nowhere. And I finally decided that the reason is they were studying the pathology of being fat as opposed to the way to become healthy. And the way to become healthy was a metabolically active tissue muscle. And so that was the whole background to it. Other pieces of the puzzle is people talk about protein and metabolism. We were studying protein turnover and we realized just how expensive that process is. I’ve seen estimates that protein turnover in the body actually accounts for as much as 40% of rusting metabolism.
And some people would say 20. It all depends on how you want to factor out transports and breakdown and all things. But anyway, the issue is it’s a really big part. And so that all rolled together to me that if we want to look at health and long-term health, what we need to do is maintain protein turnover because that maintains your body proteins healthy and it also maintains your metabolism healthy. And that’s how Dr. Gabrielle Lyon and I put together the concept of muscle centric health and protein centric diets.

Dr. Mark Hyman: Yeah. What’s so interesting is that most of us don’t think about metabolism as the source in our muscle, but that is the greatest source of our ability to burn calories and regulator metabolism, right?

Dr. Don Layman: I think the better way of saying is it’s the most flexible way to burn calories and metabolism, the heart, the kidney, the brain, a resting metabolism, something like, and I forget the numbers off the top, I should have looked it up, 70% of resting metabolism is organ based, but muscle is another part. And it’s flexible, how much do you have? How metabolically active is it? How much exercise? That changes the picture. And when we look at energy balance long term, we’re talking about hundred, 200 calories per day. So this is well within the realm of what muscle can manage.

Dr. Mark Hyman: Yeah. So I think to me, as I looked at my own biology and my N-of-1 studies, and I’ve treated tens of thousands of patients, so I’ve seen this in my patients, but I was a very active guy my whole life. I ran, I did yoga. I did not think protein was that important. In my earlier years, we learned about the importance of carbohydrates as a source of energy, and that’s what we should be doing. And in the nineties, we learned about the food pyramid and you’d have six to 11 servings of bread, rice, and pasta a day. And that’s when I was running every day. And I mean literally ran four miles to medical school every morning and four miles back every night. And I was fit, but I didn’t have very much muscle. And I picture myself at 40 and now, and my body looks completely different.
And I’m not a gym rat. I hate the gym. But I really only started strength training through bands three years ago, that’s six years old. And I’m just shocked to see the changes in my body composition and my body using the science of having the right type of exercise combined with the right kinds and amount of protein at the right times. And I’m older and so I have this tendency to what we call anabolic resistance, which means it’s harder to build muscle as you get older, which what you were saying. And yet I find I’m able to do it by using this science, which shocked me to realize how much our dietary advice was so wrong about consuming large amounts of carbohydrates, not paying attention much to protein, worried about too much dietary fat.
And it’s really created this epidemic of obesity, metabolic syndrome, and all the consequences of that really to aging. And to me, I’m maybe a little late to the game here, but to me, understanding the role of muscle and aging has been so key. And looking at sarcopenia, which I want to get into, which is muscle loss, and looking at how we address that as we get older or even at any age is so important because an abstract level, we can talk about the science of this, but the question people really want to know is, what do I have to do to build highly effective functioning muscle that keeps my metabolism good and keeps me living well and healthy and a long time?

Dr. Don Layman: I think part of the confusion is one, nutrition is actually quite a young science. I often tell my students that I actually got into nutrition learning from the first generation of nutrition researchers. So I’m like a second generation and aging does affect me now. And so it’s a young science, nutrition really grew out of studying growth in children. And what we now know is that protein metabolism is very different in a growing child than it is in an aging adult. And that’s something we’ve really just discovered in the last 20 years. One of the things we’ve discovered is issues of how much protein do you need and distribution and muscle focus. Before, it was really just about maintaining growth curves. And what we know is that you can have a child eat small meals of eight to 10 grams of protein and they’ll grow perfectly fine.
You can have them have five meals a day of snacking on 10 grams of protein, and they’ll be absolutely fine. But that doesn’t work in adults at all. Children are really driven by hormones, insulin, growth hormone, IGF-1, et cetera, where adults are no longer driven… Their metabolism’s not driven by those hormones. They’re now driven by diet quality and in a case of muscle, exercise, particularly resistance exercise. And so those are some of the things we’ve discovered in looking at things like leucine and mTOR s we know there’s a balance there of how to affect it for adults.
And one of the things I like to tell people is the average a person if you ask them about protein is they’d say, “Well, it’s really important for children because they’re growing.” Well, growth only accounts for about five grams per day of net gain, maximum growth, where everybody, you and I or a 16-year old has to make 250 to 300 grams of new protein per day just to replace body proteins. We’re constantly repairing and replacing. And the issue of aging is that process becomes less efficient. And one of the things we’ve discovered is that from a muscle standpoint, we can make that efficiency better if we choose the right amount of proteins and the right amount of resistance exercise. So the process of aging, we know it’s a slope. What we want to do is change the angle of that slope. And again, we know that protein and exercise can do that.

Dr. Mark Hyman: Yeah, it’s right. And I think most of nutrition’s been focused on fat and carbohydrate and protein’s the neglected nutrient. Oh, you get protein, whatever 20% of your diet, you’re fine. You don’t have to worry. It’s fine. The truth is that it’s such an essential part of our nutrition, not only in terms of, as you said, replacing all the hundred grams of proteins we use for all sorts of things from our immune system to structural proteins to brain chemicals. I mean, just peptides. We just go through so much every day. But it’s so important in terms of keeping your metabolism healthy as you get older, which is the key to longevity. And the phenomena that happens is insulin resistance, which is this phenomena of pre-diabetes, diabetes, or the continuum from normal all the way through that. And a big way of combating that is not only cutting back on starch and sugar, but is optimizing your muscle health, function, and amount. So you talk about the role protein plays in weight loss and regulating our blood sugar and regulating our cholesterol and triglycerides and our hormones and reversing.
Tell us about that. And particularly if we just talk about weight loss, we’re all talking about calories. Well calories, the old story about weight loss, and I think it’s the old story because I think there’s a new story, is that it’s all about energy balance, calories in, calories out. As long as you don’t overeat and under exercise, you’re fine. And that turns out to be not quite the story, because if you eat a high carb, low protein diet, you may not get the same benefit as if you’re eating adequate fats and protein and less carbohydrates starch. So can you talk a little bit through that whole range? It’s a lot, I know, but you can take your time, unpack it off, but I think it’s really where the money is.

Dr. Don Layman: Yeah. So my whole career, we’ve been studying protein turnover, as I said, and understood how much that impacted metabolism. So I’ll come back to the protein side, but in the late nineties, we had the Atkins diet and the Zone diet, and we had all these diet, we had the Jerry Reaven discovering the concept of metabolic syndrome, syndrome X. And the debate out there was a carbohydrate versus fat debate, and it wasn’t really going anywhere. It was stuck. And I thought the reason they’re not getting it is it’s not really a carbohydrate versus fat, it’s a calorie versus protein discussion. And so we started running a series of studies looking at substituting protein for carbohydrates. So the protein, what we knew, as I mentioned earlier, is that protein had a big impact on energy expenditure. In fact, people talk about thermogenic effects of protein and freshman nutrition book will say it has something to do with digestion, absorption, metabolism, which is nonsense.
It actually has to do with protein turnover. Protein turnover is a very expensive energy process. And when you trigger it at a meal, one of the things we found with animals is the amount of ATP expenditure during say an hour of treadmill running in an animal is about equivalent to the same effect of giving a protein meal. So you can either eat a protein meal or you can run an hour on a treadmill and you spent the same amount of calories. So that triggered us to thinking about muscle. And we know that there’s also satiety effects of protein. We know it repairs body functions. We know that there’s this interaction with insulin. So let’s go to the insulin story. If you look at insulin resistance forever, everybody tried to target fat. And you can design high fat rodent models.
You can design obesity models and they will cause insulin resistance. But what people, and there’s a Randle hypothesis that high free fatty acids inhibit carbohydrate metabolism and it feeds back through ceramides and diacylglycerol, and it causes insulin resistance at the receptor and all of that. And you can show that that works. But what has also been shown is that carbohydrates cause insulin resistance. It’s an energy balance thing. And what Bob Wolfe showed was that if you look at the two of them together in a highlight with really sophisticated, stable isotope metabolism, what you’ll find is that carbohydrates always dominate metabolism.

Dr. Mark Hyman: Can you explain what that means, dominate metabolism?

Dr. Don Layman: Yeah, I will. So if you look at the American diet, we get about 50, 55% of our calories from carbohydrates and 30, 38% from fat. So the dominant issue is carbohydrates. So that means associated with every meal, we have this big influx of sugar, of glucose, and the body has to dispose of it. In fact, diagnosis for diabetes, as you know, is a two-hour glucose tolerance test. And so that means basically after a meal, we have to dispose of whatever carbs came in that meal in two hours, or by definition we’re diabetic.
And so to do that, say for example, the average Americans eating close to 300 calories per day, 300 grams per day of carbohydrates. So just simple math, put a hundred grams in a meal, that means you have to dispose of almost a hundred grams after every meal. Well, the body only has a capacity of easy capacity of disposing of about 30 to 40 per hour. So that means we’re distorting metabolism with another 40 or 50 grams of carbohydrate. And the way we do that is we basically begin to disrupt muscle metabolism. Muscle is primarily a fat burning tissue.

Dr. Mark Hyman: So wait, wait, wait, wait. What you’re saying is that too much excess carbohydrates from starch and sugar disrupt muscle function and metabolism.

Dr. Don Layman: Exactly. And it disrupts fat metabolism. So basically the body has to get rid of that carbohydrate, or it causes all the damage we know as diabetes. So it basically shuts down all the fat metabolism, and hence we get higher blood lipids. Okay. That’s not because of eating the fat, it’s because of eating the excess carbs. And so what we have to look at is what is the balance? How many carbs can we use-

Dr. Mark Hyman: So wait, wait. Just slow down for a sec because I said so much important stuff there. You said that when you eat excess carbohydrates, it interrupts your muscles’ ability to regulate your cholesterol and your triglycerides.

Dr. Don Layman: I didn’t say cholesterol, I said blood lipids.

Dr. Mark Hyman: Lipids. So what did you mean by that?

Dr. Don Layman: Triglycerides particularly, free fatty acids.

Dr. Mark Hyman: Which basically are produced by meaning too much carbohydrate, right?

Dr. Don Layman: Triglyceride are measured in a fasting condition, as you know. And so basically they reflect recycling of fatty acids from adipose tissue. However, when you have a high carbohydrate diet, now you have to go into de novo synthesis of other fatty acids, and that will elevate your triglycerides. One of the things that we found in our weight loss studies is if we take individuals and lower their carbohydrate intake from 300 grams, whatever they’re normally eating, down to the RDA, which is 130 grams per day, we will drop their triglycerides by 20% or more, no matter where they start at. So we actually use that as a biomarker for a low-carb compliance. If they don’t drop their triglycerides by 20%, you know they’re not following a low-carb.

Dr. Mark Hyman: You can tell they’re cheating and having that extra bagel.

Dr. Don Layman: Exactly. It’s so predictable.

Dr. Mark Hyman: Yeah, amazing. So keep going what you were saying.

Dr. Don Layman: So the balance is the muscle has two primary fuels. It uses fatty acids and uses glucose. Its preferred fuel is fatty acids, but when excess glucose is around, it inhibits transport of triglycerides or fatty acids into the mitochondria. You get the accumulation and carbohydrates themselves will cause insulin resistance. They’ll feed back to the insulin receptor and muscle. And so people say, well, obesity causes insulin resistance, but actually just excess carbohydrate causes insulin-
PART 1 OF 4 ENDS [00:23:04]

Dr. Don Layman: Insulin resistance, but actually just excess carbohydrate causes insulin resistance.

Dr. Mark Hyman: Yeah. So that’s a very different model because I think people say, “Well, you become diabetic or insulin resistant because you are obese,” and you’re saying a little bit something different, that you become-

Dr. Don Layman: No, I think obesity is a symptom of diabetes, it’s a symptom of insulin resistance, which comes first? Well, we tend to not look for those characteristics until somebody comes in and they’re obese, they have high blood pressure, and we say, “We should look at your glucose. Oh, your fasting glucose is high. We should look at your insulin. Oh, you’re diabetic.” But the reality is it’s the other way around. It starts with insulin resistance and you become obese.

Dr. Mark Hyman: Well, that’s interesting because that’s exactly what David Ludwig talks about, who’s a Harvard researcher, about the carbohydrate insulin model of obesity, which is that you become insulin resistant and that leads to obesity and that it’s really the overeating is not the cause of obesity, but obesity becomes the cause of overeating in a kind of perverse way because essentially your fat cells become hungry and you become insulin resistant, so you need more to satisfy them.

Dr. Don Layman: Yeah, I don’t buy that kind of thinking exactly. I think of it as a muscle-centric issue. As you mentioned earlier, when you were a 20-year-old athlete, you could eat any carbs you want. Well-

Dr. Mark Hyman: But I didn’t have muscle though. It was interesting. I was fit, but-

Dr. Don Layman: But you were burning. You were burning them. And so the muscles, even though you didn’t have a lot of mass, the muscles were still very actively burning it. As we get older, once we reach 40 and beyond, now that metabolism begins to slow down. The question is, did you change your diet to drop your carbohydrates in half? And most people would say, “No, I probably increased them.” And so that’s part of the issue.
So I do feel that carbohydrates actually are a more risky metabolism, more risky macronutrient than fats because they dominate metabolism. Fats are much more passive in metabolism. I don’t really buy the whole insulin obesity theory in quite the way it’s projected. But calories aren’t equal and carbohydrates are a more risky issue. If you want, again if you take a muscle-centric approach, keeping muscle healthy and insulin active is your goal. If you’re taking a fat centric approach, now you’re trying to treat the inflammation or the pathology of being fat, and now fats probably do make a difference. I’d say to people, “If you’re committed to being overweight and obese, then probably the fats you choose make a difference, but if your goal is to be normal weight, then your calorie total’s what matters.”

Dr. Mark Hyman: So take us through that because I’m sort of hearing a conflict in what you said between carbohydrates being worse for your muscle and for your overall health, and yet you’re saying all calories are not necessarily different in that way. So I’m a bit confused and probably my listeners are confused.

Dr. Don Layman: Sure, sure. So, carbohydrates are an important fuel for muscle. And so out of the 70s and 80s we got the idea that blood sugar and carbohydrate loading and all of that was very important for performance, but now we’re talking about very high-end performance. So if we’re talking about people who are basically sedentary, maybe go for walks and things, muscle wants to use fat. And so loading up the body with a huge amount of carbohydrates, 300 grams per day means the majority of those are going to have to be converted into fat because the muscle isn’t going to use them. If you’re running eight miles a day as you were, you can burn 300 calories per day, but if you’re basically sitting in front of a computer all day, 130 maybe max that you can use. When we’re talking about-

Dr. Mark Hyman: You mean grams? Grams of carbohydrate-

Dr. Don Layman: Grams, I’m sorry. Thank you. When we’re talking to individuals about their carbohydrate threshold or their carbohydrate needs, we basically say, “Well, 130 grams is the recommended dietary allowance, that allows for five servings of vegetables, two to three servings of fruit, and three servings of grains. That’s the RDA.” Basically every gram of carbohydrate you use above that has to be accounted for by exercise at basically the rate of about 60 grams per hour of medium to higher intense exercise. So basically, the average American with 300 grams per day needs to have three hours per day of active exercise, high intense exercise to account for it, otherwise you’re going to be obese. I mean just by simple math, if 55% of our calories come from carbs and 35% from fat, how can fat be the problem?

Dr. Mark Hyman: So you’re saying that it’s our excess carbohydrates that are driving a lot of the obesity epidemic?

Dr. Don Layman: Absolutely. I mean that’s where we’re eating the excess calories and that’s, frankly, the easiest one to change. People who, the paleo, carnivore type of diets, if you reduce your grain consumption, most people will get their calories under control.

Dr. Mark Hyman: Yeah, I think that’s right. I think calories do matter, it’s just I think in my experience is if I focus on the quality of the nutrients that my patients are eating and I tell them to reduce the refined starch and sugar, increase plant-rich foods in terms of vegetables and fruit and have good quality fats, I don’t really have to tell them to lose weight or count calories. It naturally will sort itself out and their metabolism will actually increase when they do that. And I hear that’s what you’re saying.

Dr. Don Layman: Yeah. When we teach it in our weight loss clinic at the University of Illinois, the way we taught it was, you make your protein-centric decision. How much protein are going to be? And that may be vegetarian, it may be carnivore, but you make a decision about protein, then you can eat all of the high, the colorful fruits and vegetables and berries, the high fiber type of plants you want, those are your fillers. And then the starchy, sugary things, the bread, the rice, the potatoes can never be larger than basically a one-to-one ratio with the protein. And if you do that, you literally can’t overeat. It’s virtually impossible to overeat the protein part.

Dr. Mark Hyman: Right, right, right. People can eat a bag of Chips Ahoy cookies, but it’s hard to eat a 30 ounce piece of meat.

Dr. Don Layman: Yeah. You go out and you’ll have a dinner, say you had an eight ounce steak, and they come to the end of the meal and they say, “Well, would you like chocolate cake or another eight ounce steak?” Very few people will choose the eight ounce steak. You just can’t eat more of it. It’s satiating. You just get full of it. Even if you’re a carnivore and you like it, you still get full of it.

Dr. Mark Hyman: Now you-

Dr. Don Layman: You can always eat another donut.

Dr. Mark Hyman: That is true. So you basically were sharing some of your research around how eating the same calories, if it’s higher carb, low protein won’t give you the same results as eating the same calories if it’s higher protein, lower carbohydrate. Right?

Dr. Don Layman: Right.

Dr. Mark Hyman: Can you explain that?

Dr. Don Layman: Yeah. So we did a series of weight loss clinical trials-

Dr. Mark Hyman: And the reason I’m asking, sorry to interrupt, is because most of us still believe that it’s just about energy balance, calories in, calories out is all you have to worry about and if you burn more than you eat, you’re going to be fine.

Dr. Don Layman: And the reality is the choice between carbohydrate and fats, it’s pretty much calories in, calories out. They kind of burn about the same, but protein is totally different. So, let me describe, so the second of the series of studies that we did was a two by two experiment where we had high carb, low protein. Basically it was the food guide pyramid, followed it exactly, so a great diet. And the other diet was a high protein reduced carb, basically we substituted protein for carbs gram for gram. Okay? This was four months, 16 weeks, 48 women on the study. At the end of it, both groups lost weight, so calories do matter. I may not quite get these numbers correctly. Women on the high carb diet, not using exercise lost 14.8 pounds, I think it was pounds. Yeah, 14.8 pounds in the 16 weeks.
And then we had another group, the same diet, but doing exercise, so this exercise, and we can get into the exercise issue, but they were doing seven days a week, 30 minutes a day of exercise, 16 weeks they lost a 10th of a pound. So it went from 14.8 to 14.9. So really no difference from the effort. But if we looked at the body composition, the individuals who were on the high carb diet, low protein, 64% of their weight loss was fat, which means 36% was lean tissue. And we believe that is one of the issues for diet rebounds, that people are losing their lean tissue, particularly muscle during these restrictions, and therefore their resting energy expenditure, their ability to burn calories goes down, they will rebound. And when they rebound, they’ll gain back the fat and not the muscle. They’re worse of for having doing it.
So the carb group plus the exercise, what we found is that the composition went to 78% of the weight loss was fat, so now only 22% was lean. So the exercise had a bit, it didn’t show up on the bathroom scale, but it showed up in composition.

Dr. Mark Hyman: And that matters for metabolism, right?

Dr. Don Layman: Tremendous effect on metabolism. Next group then is the low carb, high protein. After same 16 weeks, what we found is they lost something in the 17 and a half pounds. So with the exact same calories, they lost three pounds more weight.

Dr. Mark Hyman: More weight.

Dr. Don Layman: And what we found was they lost almost 300, they burned almost 300 calories per day more.

Dr. Mark Hyman: More.

Dr. Don Layman: We then looked at body composition and their composition was 76% fat loss, 24% lean. So basically the carbohydrate with seven days a week of exercise was the same as doing a higher protein diet-

Dr. Mark Hyman: Without exercise?

Dr. Don Layman: Without exercise. Without any. So just basically changing your diet to higher protein was equivalent to adding seven days a week of exercise. Which of those looks easier?

Dr. Mark Hyman: And did the fat remain constant in terms of calories?

Dr. Don Layman: The dietary fat, the dietary fat was just slightly higher in the high protein diet. So in the low protein, in the high carb diet, they had approximately 40 grams per day of fat, and in the high protein diet, they had approximately 50. So a little bit higher. Same calories per day though, slightly different macronutrient composition.
The last one, we went to the high protein plus the same exercise, they now lost 19 and a half pounds, so five pounds more doing exactly the same effort, same diet, same calories, and now the weight loss was a little over 90% fat, only less than 10% lean. So basically we saw the synergistic effect. And so one of the things I like to point out is that basically the synergistic effect of protein plus exercise, as far as body composition, but the converse of that is that a high carb, low protein diet negates the benefit of doing exercise.

Dr. Mark Hyman: Well, that’s a big discovery. If you’re eating a high carb diet, you can exercise and you’re not getting ahead.

Dr. Don Layman: Basically following the food guide pyramid dramatically reduces the effect of doing exercise. That’s not-

Dr. Mark Hyman: Wait, wait. So let me summarize this. So basically if you eat a high carb diet, lower protein, and exercise, you’re worse off than if you don’t exercise and eat a higher protein, lower carbohydrate diet? And the other thing, just to clarify, is I learned that muscle obviously burns far more calories than fat, and I heard seven times as much. So if you actually are gaining and losing weight, and I don’t know if the seven times is right or not, I just learned that years ago and I had that stuck in my head, but it’s definitely more. So if you lose weight and then you gain back the weight, you’re losing muscle and fat, but then you’re gaining back fat. So basically you could be the same weight you were when you started and actually have a slower metabolism and be burning less calories, so you actually eat less. And I’ve seen this in my patient, go, “I don’t eat that much,” and they’re very obese. And I’m like, “This is because you’ve basically replaced your muscle with fat and you have such a slow metabolism.”

Dr. Don Layman: Yeah. Yeah. I mean that’s what people refer to as the yo-yo dieting problem is that you lose weight, the bathroom scale says you’re being successful, but you’re not correcting body composition. And when you gain it back, adults don’t gain back body muscle very well. It takes enormous amount of resistance exercise to gain it back. So when you gain it back, what you gain back is the fat. And so now what you have is a worse body composition.
One of the things, my dieticians, when we were doing the weight loss studies, they always used to, when they brought people in, they would always ask them about previous diets and they always referred to individuals as weight loss virgins because if they were, if they hadn’t gone through yo-yo diets, they would be much more successful on any of our treatments.

Dr. Mark Hyman: Interesting.

Dr. Don Layman: So if they’d already messed up their body composition with previous diets, they were never quite as successful.

Dr. Mark Hyman: It’s so interesting. And when you’re talking about the protein of those diets, what was considered “high protein” in terms of point what per grams or kilo?

Dr. Don Layman: So the food guide pyramid recommends the RDA, so that’s 0.8 grams per day, which is 0.36 pounds per day, sorry, 0.36 grams per pound. anyway-

Dr. Mark Hyman: Yeah. And that that’s the minimum amount for just maintaining health.

Dr. Don Layman: Absolutely.

Dr. Mark Hyman: That’s not optimal amount for-

Dr. Don Layman: Absolutely. It’s the minimum that you don’t see deficiencies. And just for the frame of reference of women over 65, 40% are below that number. 40% are below that number. So back to-

Dr. Mark Hyman: Wait, wait. That’s just a huge bombshell you dropped because the prevailing narrative out there is that we as Americans eat too much protein and you just said that 40% of women over, well 65 you said, don’t get enough protein.

Dr. Don Layman: Don’t meet the minimum, don’t meet minimum. Don’t meet the-

Dr. Mark Hyman: Minimum? Not the amount we need for optimal health, but the minimum, basically how much vitamin C you need to not get scurvy, 60 milligrams. It’s not very much. Or how much vitamin D you need to not get rickets, 30 units. So you’re talking about really not optimal levels for health. Maybe you need 1,000 or 2,000 to 5,000 for vitamin D to be healthy, right?

Dr. Don Layman: Yeah. And I don’t quite remember the statistic on this one, but in women 16 to 26, I think it’s 30% are below the RDA.

Dr. Mark Hyman: 16 to 26, 30%?

Dr. Don Layman: Yeah. Very young women, they’re all conscious about weight loss and they’re eating extremely low. So we’ve got the two extremes. Men, not so much. Men tend to make the minimum okay, but again, not the optimum. We think the optimum’s about twice the RDA, so 0.8 grams per kg. Our diets were aimed at 1.5, 1.6. In women, we find the metabolism, there’s a threshold of around 100 grams per day. If they fall below 100 grams per day, we lose a lot of the metabolic effects. So we tried to target women in the 100 to 120 grams per day range. And people say, “Well, it relates to body weight.” Yeah, true, but in our weight loss studies, we had women everywhere from 140 to 300 pounds, and we found that number still worked pretty well.

Dr. Mark Hyman: That’s remarkable. I mean that is a lot more than most people are thinking about as being.

Dr. Don Layman: Absolutely.

Dr. Mark Hyman: And now you’re talking about a younger person. You’re not talking about someone who’s like 70 who may need even more than that.

Dr. Don Layman: So we’re talking about metabolism that’s really geared for people over 40. Again, I mentioned earlier that young people will grow on small amounts of protein distributed, and when we’re young, we can kind of abuse our bodies and it looks okay.

Dr. Mark Hyman: I know I’m not able to abuse my body like I used to, for sure. I know that.

Dr. Don Layman: A 20-year-old female on a really low protein diet probably is okay, but you start getting a 60-year-old female on a low protein diet and they’re not going to be as okay. You’re going to see it in their skin, you’re going to see it in their hair, you’re going to see it in their muscle mass. You’re going to see it in different ways. So we always want to kind of realize that young people and older adults are very different in how we think about metabolism. We always say that someplace in the end of your 30s to your 40s, you should be making a pretty conscious diet change and most people aren’t.

Dr. Mark Hyman: So you’re not even talking about when you get to 50, 60, or 70, you’re talking 30s or 40s we need more?

Dr. Don Layman: Let’s measure, we can measure these changes in protein metabolism, and people know you can measure changes in bone metabolism starting in your 40s. So in that fourth decade, after 40 we know that some of the things that we measure in terms of distribution of protein, protein at meals, we can detect the difference in mid 30s.

Dr. Mark Hyman: Wow. What you’re saying is sort of revolutionary and goes against a lot of the prevailing views out there, which is that-

Dr. Don Layman: I’ve been told that before.

Dr. Mark Hyman: But it’s based on your, it’s not just based on nothing, it’s based on decades of research and very rigorous research-

Dr. Don Layman: It’s based on 40 years of research where we have actually tested these things and measured that both in animals and in humans, and we’re pretty confident in how these work.

Dr. Mark Hyman: So what you’re basically saying is-

Dr. Don Layman: And we know the mechanisms behind it.

Dr. Mark Hyman: Yeah. Well, we’re going to get into the mechanisms in a minute, but basically you’re saying is that all calories are not exactly created equal when it comes to how they affect your metabolism.

Dr. Don Layman: Yeah. And absolutely related to protein. You can have a little bit different kind of debate about carbs and fat, but protein is 100% different in metabolism and it’s the only essential macronutrient. The other two are just calories. We have-

Dr. Mark Hyman: Well, there’s essential fatty acids, but yes, right.

Dr. Don Layman: Maybe three grams per day.

Dr. Mark Hyman: Those are small, right.

Dr. Don Layman: Yeah. We’re eating 70 to 80 grams of fat per day, three are essential, so yeah.

Dr. Mark Hyman: Yeah, yeah. Exactly. Exactly. So I just want to take a little sidebar for a minute and I want to get back into the protein conversation about what kind of protein, what is the amount of protein, what does it look like, quality of protein, leucine, a lot of things I want to talk about, but I want to take a sidebar on another study that was very similar to yours, which put people in a metabolic lab and gave them food and measured their metabolic rate when they had isocaloric same calorie diets, but one was, let’s say, 60% fat, 20% carb versus let’s say 10% to 20% fat and 60% carb. So high carb, low fat versus low fat, high carb.
And this was David Ludwig’s study and what shocked me in that study was, even though they were eating the same amount of calories, the metabolic rate, particularly in those who were already insulin resistant, was 400 calories slower in those who had the high carbohydrate, low fat diet. And the high fat group burned basically 400 calories more a day. You have any thoughts on that?

Dr. Don Layman: Yeah, I can’t really speak to that. I’m not sure I’m familiar with that specific study. Kevin Hall has some similar metabolic studies and doesn’t find those kinds of differences.

Dr. Mark Hyman: Well, those are short-term studies. Those were like two week studies, so that’s the difference in… Fat adaptation takes a while, so I think that was part of the flaws in that.

Dr. Don Layman: Yeah, I can’t speak specifically to those two studies. My reading of the literature is that, from a calorie standpoint, fat calories, carb calories, they’re still just calories. I do feel that…
PART 2 OF 4 ENDS [00:46:04]

Dr. Don Layman: … just calories. I do feel that when you’re-

Dr. Mark Hyman: Fat is not insulinogenic, right? So if you drink a liter of olive oil, your insulin doesn’t go up.

Dr. Don Layman: So what I was going to say is that if you’re in excess calorie situations, high carb diets will cause more problems because of the insulin issues and chronically, high insulin. If you look at the time course of insulin resistance, what you’ll find is that as an individual becomes insulin resistance, the body will slowly increase the amount of insulin released at a meal to try and keep blood glucose stable. And it keeps going up and up until basically it damages the pancreas and you could no longer sustain that.
And people then go to external insulin and other kinds of drugs, et cetera, et cetera. But basically continuously increasing your carbs to force the body to dispose of them causes insulin resistance.

Dr. Mark Hyman: Yeah, absolutely. Now I want to get … Now, thank you for that sidebar. I want to get into an area that may be as controversial as being a Republican or a Democrat or being-

Dr. Don Layman: Let’s not go there.

Dr. Mark Hyman: Jewish or Muslim or whatever. It’s vegan versus not vegan, right? And I think there is so much media, and I would say information out there online and in movies that seems to convince people that you can get adequate amounts of protein and build massive amounts of muscle being vegan.
Now, I just got back from Rwanda. I was on a vacation and it was one of my bucket list things, and I went to see the gorillas. Now, the gorillas, have you ever seen gorilla? They’re huge, massive amounts of muscle, and they are essentially vegan except for a few insects. And what I didn’t know before I went was that they eat 55 pounds of food a day, and they eat half the day, and they have these enormous intestines. Those giant bellies that they have are not fat. They’re their intestines.
So can you speak to this whole idea of can you actually adequately meet your protein needs being strictly vegan, especially as you age? And can you talk about some of the research around, and I’ll kind of repeat the question around mTOR activation and the idea that we want to inhibit mTOR, which is this part of our cellular metabolism that activates muscle synthesis, but it also, when you inhibit it, it actually increases autophagy, which mimics calorie restriction, which is the thing that’s been proven to extend life in all animal models.
So help us sort of understand, one, can we get adequate protein being vegan, and especially as we age, and two, how do we deal with this basically seemingly contradictory idea that we should inhibit mTOR to extend our life, but we need muscle to be more as we age to be healthy. So help us with that.

Dr. Don Layman: So wow, unlocking a lot of different things there. So the vegan story, you can be perfectly healthy as a vegan, but it is tough. Basically what we know is that to be equal, you have to eat more total protein and more total calories. So gorillas are stuffing themselves. Basically, the solution to that is they better be physically active.
And so being a vegan at 25 or 35 works a whole lot better than being a vegan at 65 or 75. Now you have both physical activity and metabolic rates going down, and it’s hard to eat enough to get to it. My comment earlier that 40% of women over 65 don’t get enough protein just to be equal. And being a vegan doesn’t make that better.
So I think there’s an age issue in it. My problem with vegans is when they sort of take a moral superiority approach to it. I have no tolerance for that. If you want to do it for a personal reason, if you want to do it for some metabolic reason, cardiovascular disease, you’ve got really high LDLs or something, I’m okay with that. High fiber, okay, I’m okay with that. Is it metabolically better? I don’t think so.
I think that a balance of animal foods and one of the things you have to look at it is not only can it be done, the issue is can people do it? And in the United States, most people have nowhere near the food knowledge or the food skills to pull that off. In the United States, we get 70% of our calories from plant-based foods now, only 30% from animal-based foods. Of that 70%, 51% comes from added sugars, oils and hydrogenated fats. And another 33% comes from refined grains. So of the 70%, 80% have no nutritional value. They’re just crappy calories.
And if you look at the 30% of the calories coming from animal foods, basically we’re getting 65% of our protein, a hundred percent of calcium, vitamin D, B12, and over 60% of iron, zinc, selenium, B6, niacin. So the question is, if we take calories out of that animal fraction, what are we going to eat? Are we going to eat broccoli and Brussels sprouts and green beans? Are we going to eat bread and candy bars and donuts and french fries? I mean, that’s what Americans eat.
Right now of our plant-based protein in the US and worldwide, 80% of the protein comes from wheat, which is absolutely lousy protein source.

Dr. Mark Hyman: Well, wheat as a flour, particularly not even as whole wheat, right?

Dr. Don Layman: Whole wheat or not-

Dr. Mark Hyman: Whole grain. I mean most people don’t eat wheat berries. They eat either whole flour or white flour, which isn’t that different.

Dr. Don Layman: Sure. Like I just said, 33% of it comes from refined grains, et cetera. So a lot of it is from … But anyway, the point is people aren’t eating beans and lentils. They’re eating french fries and bread.

Dr. Mark Hyman: But Don, let’s say they work because let’s just say if you want, let’s say 30 grams of protein. In chicken, let’s say it’s 4 ounces, which has about 270 calories. If you want, let’s say beans, let’s say black beans, that’s two cups of black beans to get 30 grams of protein. We talk about protein quality. That’s 450 calories.
So if you want to have 30 grams of protein, that’s fine. If you want them 120 grams, that’s four times that. That’s like 800 calories from protein versus thousands of calories. And if you took brown rice, you have to have 24 cups of brown rice a day, which has 1,200 calories times six, I’m not good at math. But that’s like 20,000 calories a day to get enough protein from brown rice, right?

Dr. Don Layman: Yeah. So a hundred percent agree. My first point was that if you’re going to be vegetarian or vegan, you’re going to have to have more total protein because the quality’s down and more total calories to your point right now. I mean, the average beans, black beans, for example, are between three or four to one carbohydrate to protein.
So if I want a diet with a hundred grams of protein, by definition, I’m going to have to have 350 grams of carbohydrates, which we already said most people can’t metabolize. It’s just too many calories. So it’s much harder. It can be done. It’s much easier-

Dr. Mark Hyman: How could you do it really? Because if you’re eating, let’s say-

Dr. Don Layman: The bottom line is that almost all vegetarians reduce their protein intake. All of the studies say that the average protein intake for vegetarians is in the mid-60s. The average adult intake in the United States is women are around 70 and men are around 90. So they’re reducing their protein intake, they’re reducing their protein quality. When you’re young, you can kind of get away with it. When you’re older and you’re stressed with sarcopenia, not so much.

Dr. Mark Hyman: When talking about protein quality because people say, “Oh, you have beans and grains, you combine them, it’s great, you can get full protein and that’s fine.” But just doing the math, if six cups of brown rice has 30 grams of protein, you multiply that four, that’s 120 grams, that’s 31,000 calories. Not to mention how many carbohydrate grams are in there. And then when you add protein, the 450 grams of protein … I mean, 30 grams of protein in two cups of beans, that’s 450 calories times four to get 120 grams, that’s 1,800 calories.
So you’re going to be eating so many extra calories with also carbohydrate, unless my conclusion, unless you actually have pulverized concentrated protein powders that are made from plants and add extra leucine and branched-chain amino acids on top of it, it’s going to be very hard to do this. And I’ve met these guys who are bodybuilders who are vegans, and they eat jacked-up plant proteins, powders, not food.

Dr. Don Layman: I think, yeah, again, the national surveys, the NHANES data and others all say that average vegetarians are in the low 60s protein per day. So if you’re going to try and get to 120 grams, to your point, you’re going to have to have isolated purified proteins. You can’t do it with eating food because you’re just going to get too many calories.

Dr. Mark Hyman: So people who are vegan vegetarian, and by the way, I was a vegan vegetarian for 10 years or more actually when I was younger. So I get this, and I understand why. And then there’s three real issues: Health, environmental, and moral. And moral, I can’t argue with. Health is a more complicated, and I think environmental, it’s very nuanced in terms of regenerative agriculture, and we can talk about that.
But I think I sort of want to get into the protein quality because I read Diet for a Small Planet, and if you combine protein from beans and grains, you get complete protein and you don’t have to worry. And yet the thing that you talk about, which is really unique and that I learned from Gabrielle Lyon, my friend who was your student, was that leucine is a rate-limiting amino acid in protein synthesis.
And in English, that means if you don’t have enough of this particular amino acid, you can’t turn on the switch like flipping a switch to turn on your engine to build muscle unless you have that amount. And typically, plant proteins are very low in this particular amino acid, leucine and other branched-chain amino acids. So can you help us understand that concept and what do we do about it?

Dr. Don Layman: Yeah. There are nine essential amino acids. And interestingly, they’re not all equally essential. The ones that show up most in diets, you mentioned leucine. The other two are lysine and methionine. All grains are very low, and rice, et cetera. All grains are very low in lysine, and all legumes, beans are very low in methionine, and they’re both pretty low in leucine.
And so you’ll see advertisements that say, well, this plant protein contains all the essential amino acids. Well, every protein contains all the essential amino acids, but they’re not in the right proportions. The thing I always like to say is that plants have proteins for the sake of the plants. They’re building roots, leaf, and flowers and seeds, which are pretty different than brains and hearts and livers and muscles.
Your comment about animals, we have evolved to use animals to correct that balance for us, particularly ruminant animals. They have the ability to take plants and basically convert those back into amino acid balances that are correct for humans.

Dr. Mark Hyman: And they eat all day, they eat all day, and they eat enormous amounts of food.

Dr. Don Layman: Exactly. And so those are the essential amino acids that are missing. What we know, and what my lab discovered is that when you are young, as I mentioned earlier, the protein synthesis particularly in muscle is driven by hormones. But after you stop growing into your thirties, now it’s driven by diet quality and by exercise. And diet quality, the body for reasons that I love to think about has learned to recognize leucine.
I started studying these branched-chain amino acids back in graduate school. I was fascinated by them. There were some early studies, some great researchers that showed that leucine could stimulate protein synthesis in certain kinds of muscle, diaphragm and things like that, back in those days. And Al Harper at Wisconsin and some others had also shown that leucine is not metabolized in the liver. Where all other amino acids are metabolized in the gut and the liver, the branched-chain amino acids leucine, valine and isoleucine aren’t.
And so they end up going from the diet, the gut, into the bloodstream basically in the exact percentage that you ate them. So muscle now can see the diet. Muscle is getting a dose of how to … What did that meal look like by the amount of leucine that shows up? And for reasons we don’t really know, it learned to sense that as a trigger for protein synthesis through a mechanism we now know as mTOR.
What my lab discovered was that this leucine signal triggered the initiation process of protein synthesis. And the last 20 years, hundreds of labs have looked at that process. But we know that as an adult, not so much as a child, but as an adult, the amount of leucine at a meal is an absolute key to maintaining your muscle health, maintaining your muscle protein synthesis.
And so that’s a key part of diet. And to your point, all plants are relatively low in leucine. And so quinoa, for example, to use whey protein at a meal, you can eat 23 grams of whey protein, about 120 calories, and stimulate muscle protein synthesis. Where quinoa, it takes something like 50 grams of protein and 2,000 calories to make the same effect. You just can’t-

Dr. Mark Hyman: So almost 20 times the amount of calories to get the same amount of leucine?

Dr. Don Layman: And so again, quinoa has leucine in it, but it’s at such a low amount. And the nutrient density is so low, the relationship to calories is so low that you can’t eat enough of it.

Dr. Mark Hyman: This is such a radical idea that you’re talking about, Dr. Layman, because you would get so much pushback from the vegan community that this is true. And yet this is just basic science. This is not controversial. This is not in any way challenging the decades of research that you’ve done and others have done to prove that this basic biology of building muscle requires this particular amino acid leucine at a particular amount per meal, which is about two and a half grams.

Dr. Don Layman: And people will say, “Well, if you do the right complimentary proteins, if I take my wheat and I combine it with corn and I combine it with pea, and I do this and I process, I can make a balance.” And absolutely you can do it. All of the vegans who understand this process now, to the point we made earlier, are almost all using supplements. They’re using protein powders.
You just can’t do it with just pure natural foods. You have to do some sort of processed powder to get to it. Otherwise, you’re going to end up in the low 60s, that you just can’t eat enough food to get to that protein level.

Dr. Mark Hyman: And the amino acid supplements that people will get, or add a leucine, they can be gotten from plant proteins. You don’t have to get them from animal proteins. So if you want to be strictly vegan, can you synthesize them in the lab from plant components and then add them to a protein powder? Or where’s it coming from, is what I’m asking.

Dr. Don Layman: So I was talking about protein powders where you’re isolating a protein from pea, the whole protein and it’s 70% pure or something. Amino acids, the primary source of amino acids is yeast. So they’re grown in yeast environments and then they’re isolated from that.

Dr. Mark Hyman: So it’s not a plant, but it’s some kind of a … Okay, I got it. So ethically, it’s okay. And if you’re committed to being vegan, you just have to understand that you can’t get around this science of needing this amount of leucine per meal to activate muscle synthesis, and especially important as you’re older. So you have to either take these additional supplements or take the extra protein powders with extra leucine.
And I know this, for example, vegan protein powders that are jacked up. I call them jacked up, where they add branched-chain amino acids and they add leucine to supplement. And those can be very effective. So I’m not saying you have to eat meat, I’m just saying you have to get real about the science of muscle. Otherwise, you’re going to end up having poor metabolic health, aging faster, lower hormones and more inflammation and all the things we see with aging.

Dr. Don Layman: Yeah, I mean, if you go back in history in the 1980s, we got a recommendation for plant-based diets. It was called the food guide pyramid, you mentioned this earlier. And people responded to that and they decreased dairy consumption, egg consumption, and beef consumption by 35% in each category. And they increase grain consumption by 40%. And we got epidemics of obesity, diabetes, and no change in heart disease at all.
So the issue is can you create a healthy plant-based diet? Well you can, but you can also create a very unhealthy plant-based diet. And that’s what most Americans have done. That’s my problem. If people say, do we need a more plant-based diet? I say we need a diet with better plants.

Dr. Mark Hyman: I like that. I like that. Okay, so I want to flip this upside down a little bit because there’s the aging question and this whole issue of mTOR, and I’m just going to explain that a little bit for people. But basically, one of the key things we’ve discovered as we age is that there are a number of things that go wrong, and one of them is deregulated nutrient sensing. It’s one of the hallmarks of aging.
And one of the key pathways that gets dysregulated is mTOR. mTOR stands for mammalian targeted rapamycin, which is essentially named after this compound, those phantom Rapa Nui on Easter Island that inhibits this particular pathway called mTOR. mTOR is required to build muscle, but also if you overactivate it and don’t give it a break, you can inhibit this process that’s critical to longevity called autophagy, meaning you clean up your cells. It’s like the recycling and garbage disposal system in your body.
So in other words, if you just cooked all day in your kitchen but never clean up, it’d be a freaking mess. And that’s kind of what we’re doing with our diet. So how do you reconcile the need for regular leucine consumption to build muscle with aging and muscle being the currency of aging, and this problem of needing to give mTOR a break or inhibit mTOR and not stimulate mTOR with leucine, which is the primary stimulator of it, and saying we would need to actually eat less protein as we age or actually avoid animal protein because it’s high in leucine?
Because this is the debate going on right now, and I need you to help kind of navigate it because you’re the expert.

Dr. Don Layman: So let’s talk first about mTOR and then let’s talk about the aging studies. So first thing to know about mTOR is it’s present in every tissue in the body and it regulates differently. So we’ve been talking about mTOR in muscle, but how about in liver or a tumor cell or whatever? There are multiple regulations of mTOR. We’ve been talking about leucine and exercise, but the other two are insulin and ATP.
So now we have four regulations. What we know is that in liver, protein synthesis is regulated by energy. What we know is that protein synthesis muscle is regulated by leucine. So now we’ve got different things going on. What we know is in tumor cells, it’s regulated by insulin and energy, not by leucine. So now we’re beginning to get this dichotomy going on. When we teach-

Dr. Mark Hyman: Because people don’t realize that mTOR, not only stimulated by protein, but also by sugar.

Dr. Don Layman: Insulin.

Dr. Mark Hyman: Insulin.

Dr. Don Layman: Stimulated by insulin.

Dr. Mark Hyman: Insulin, which is caused by too much sugar and starch, right?

Dr. Don Layman: Exactly. So now, we’ve got this problem going on is that we have high carbohydrate diets, we have high insulin environments. We know we actually did some breast cancer …
PART 3 OF 4 ENDS [01:09:04]

Dr. Don Layman: Environments. We actually did some breast cancer research and we know that tumor promotion is far more promoted by insulin than it is by leucine or or high protein. So we’ve got this dichotomy going on now. One of the things that we also teach about protein for muscle is it’s meal based. And the reason we want to do that is we want to turn mTOR on and off. And so we teach about optimizing protein at about five hour intervals. The worst thing you can do with protein is eat it in small doses all day long like vegetarians do. Because that chronically stimulates it. And now what you’ve got is the problems, the potential that you’re talking about is too much mTOR all the time. What we want to do is turn it on. And again, mTOR isn’t like an anabolic hormone. mTOR is a switch that turns on initiation factors.
And what it does in muscle is it turns on capacity factors. There’s an initiation factor called eIF4, another one called S6. It’s a ribosomal protein. And basically what these do is they increase your capacity for synthesis, particularly of structural proteins. That doesn’t work the same in other tissues. It’s a muscle specific kind of effect. So we want it to turn it on and then mTOR should go away. We want it to turn back off. Once you turn on these ribosomal proteins and this mRNA recognition and things, it’ll run for two, three hours. You want mTOR to be turned off.
So now we get into the longevity studies and you’re going to say, “How are those run?” Well, the way they run is they put a rodent in a sterile cage and they give them food ad libitum. So they’re eating constantly 24 hours a day. You can open up their stomachs and they have gut fill 24 hours a day. So basically we’ve now turned on mTOR 24 hours a day, and lo and behold, you get problems. Then what they do is they restrict the animal and then compare this ad libitum to a restricted, and as soon as you restrict an animal, what does it do? It goes to meal feeding because it will eat its food and stop and then fast for the rest of the day. So now you’ve gone to meal feeding and now you correct the situation.
They’re trying to argue it’s a protein restriction. It’s really a calorie restriction. Rats and actually rodents overeat by 40% when left in an ad libitum cage. At the University of Illinois we considered a 40% restricted rodent ate normal. So a 40% restriction just normalizes them. Basically, we know that obesity shortens longevity, and that’s what those longevity studies are showing. Overeating is bad. Okay, we agree. But to basically say it’s a leucine mTOR study is basically ignoring the science that basically mTOR and leucine are required to keep muscle healthy, and we know that longevity, that muscle really is highly critical to everybody having a healthy aging process. So we’ve got that dichotomy of how the studies were run, but basically mTOR and leucine are critical for healthy long-term muscle.

Dr. Mark Hyman: So basically it’s about when you eat. I call it the Goldilocks problem. You want to simulate mTOR at the right times, in the right amount, in the right way with the right quality of protein. But you don’t want to do it all the time every day 24/7. And you want to give yourself a break and allow mTOR to be inhibited, to initiate autophagy, clean up your cells and kind of mimic calorie restriction or actually be calorie restriction, which then helps you extend your life. Is that what you’re saying?

Dr. Don Layman: Yeah, I think that’s a totally reasonable way to look at it.

Dr. Mark Hyman: And I do worry because I see people who are plant-based as they get older, they get really frail and they get really weak. And I mean-

Dr. Don Layman: I don’t do that. My colleague, Gabrielle Lyon sees that type of patient and she works in the gerontology. She actually did a gerontology residency at Wash U, and that’s exactly what she sees. People who are low protein, they become more frail. I think it’s three hundred thousand hip fractures and individuals over 65 per year in the US, and one third of those never leave the hospital.

Dr. Mark Hyman: Wow. So let’s talk practically about how much protein you should eat in terms of food and when you should eat it in terms of the day, and then this whole controversy about time restricted eating, what’s the right math here?

Dr. Don Layman: So what we-

Dr. Mark Hyman: Asking for a friend.

Dr. Don Layman: Yeah, I get it. I get that email all the time, by the way.

Dr. Mark Hyman: I know. I’m sure you do.

Dr. Don Layman: So after we sort of discovered this leucine mTOR relationship and working with colleagues at Galveston, University of Texas, Doug Patton Jones and I were looking at the American diet and we realized that the average American eats 65% of their protein at one meal late in the day. And we started thinking about protein turnover and muscle. And so when you go into a nighttime fast, your muscle becomes very idle, but all of your other organs are working perfectly fine. In the middle of the night your liver is making proteins, it’s turning over enzymes every hour. And so you have to keep building proteins in your liver.
And so the question is, where do those amino acids come from? Well, during the middle of the night they’re coming from muscle. Muscle becomes catabolic and it’s breaking down. And so during that 12 hour fast, you’re catabolic, breaking down muscle. When you wake up in the morning and you eat no protein, you’re still catabolic, you’re breaking down muscle. Until you have a meal that has at least 30 grams of protein, at least 2.5 grams of leucine, you’re catabolic. So the average American… And the other thing we discovered was that the meal effect of protein gives you an anabolic period of about two hours. So what we have in the United States with adults is we have a two-hour anabolic period around dinner and a 22-hour catabolic period the rest of the day.

Dr. Mark Hyman: So anabolic means building muscle, catabolic means breaking down muscle just, for the average person out there.

Dr. Don Layman: Throughout that nighttime fast we’re breaking it down to give amino acids to the liver, the organs, the gut, the kidney, the brain, and then we have to replace those. If we don’t replace them, that’s aging. That’s sarcopenia. That’s a steady loss of muscle over time. And so what we decided, what Doug and I looked at and said, what we need to do is move that protein, we’re probably eating too much at dinner. Let’s move it to the first meal when you come out of that fast.
And so when we did that in animals or in humans, what we found is we immediately corrected this muscle loss and corrected body composition. So distribution for me is putting more protein into that first meal after an overnight fast. Second meal, interestingly enough, nobody’s ever really studied it. So we know that the first and last meal are really important. We assume the middle meal is important. The study that Doug and I ran actually used an even distribution and everybody has run with that. You need 30 grams per meal, every meal. That was just a coincidence. We thought the design was cute. The real issue is we move protein to breakfast.

Dr. Mark Hyman: So people shouldn’t worry so much about getting 30 grams at every meal. It’s about the total amount during the day.

Dr. Don Layman: When I talk to people, I say, I would like to see you get 45 at breakfast. I would like to see you get whatever, 20 to 35 at lunch depending on how you’re trying to control calories and another 45 to 50 at dinner. That’s the pattern that I personally use.

Dr. Mark Hyman: And is there anything to the idea that if you don’t have a at least 20 to 25 or 30 grams at a meal that you can’t turn on mTOR for muscle synthesis?

Dr. Don Layman: Exactly.

Dr. Mark Hyman: So in other words, if you ate 10 grams of protein, it’s probably you’re just burning calories. It doesn’t actually activate the system.

Dr. Don Layman: Again, liver versus muscle or regulated difference. So if you have 10 grams of protein at each meal, your liver and kidney and brain will look okay.

Dr. Mark Hyman: They’re working.

Dr. Don Layman: You’re done. They’re still fine because they’re not regulated by leucine. Muscle is. And so it’s not that it’s just burned as calories because frankly all protein is just burned his calories, interesting point if you think about it, it’s just that it’s not going to protect muscle. And so the minimum amount, so the studies that were run multiple studies by multiple groups, but one that was sort of the first was by Bob Wolf’s group at Texas and basically they looked at what was the equivalent of giving 1.7 grams of leucine versus 2.7, and they found that 1.7 had no effect at all. Basically muscle was totally idle. 2.7 totally turned it on. So we know there’s a steep threshold somewhere between 1.7 and 2.7. We’ve sort of calculated that out, and you’ll see most people will say 2.5, we don’t know whether it’s 2.3 or 2.5, anyway.

Dr. Mark Hyman: So basically what you’re saying is if you want to get two and a half grams or so of leucine you need about four to six ounces of meat or chicken or fish and about 20 to 25 grams of some kind of whey protein.

Dr. Don Layman: Yeah, exactly.

Dr. Mark Hyman: Great. Okay. So that’s like a take home, I think. And that’s good, that made me feel good because basically Americans are eating sugar for breakfast, bread, muffins, bagels, cereal, pancakes, French toast, sweetened yogurt. I mean, your average Yoplait yogurt for breakfast has more sugar than a can of Coke, perhaps.

Dr. Don Layman: Yeah. The average American breakfast is somewhere between 75 and a hundred grams of carbs and about 10 grams of protein.

Dr. Mark Hyman: So that made me feel good because this morning I had about 22 grams of goat whey and then I added extra protein. I added, it’s a combination of pumpkin seed, pea protein, and bovine collagen. So I put all that together and I get about 40 something grams of protein. So I actually feel like I’m doing a good job.

Dr. Don Layman: I had almost the same combination, frankly.

Dr. Mark Hyman: And I know people have been talking, and this is just a little bit of sidebar, is about the idea of collagen and collagen protein. Can you talk about the challenges with that? I know you’ve put your head back, so just telling everybody who’s listening not watching the podcast, he just threw his head back and rolled his eyes. So what is the deal with that?

Dr. Don Layman: Yeah, so as a protein expert, we make fun of collagen. It probably is the single worst protein on the face of the earth. It’s deficient in at least three essential amino acids-

Dr. Mark Hyman: Choline and-

Dr. Don Layman: -lysine, tryptophan, extremely high in arginine and glycine. People talk about hydroxyproline, hydroxyglycine, but the body can’t use those. Basically once an amino acid is hydroxylated the body can’t use it anymore. And so basically it’s an absolutely crappy protein.
If you look for studies, basically you’ll say, well, it seems to improve skin health and it seems to improve this and that. It makes no sense and there’s no mechanisms to back it up. I frankly think it’s a waste of money. I just don’t buy it. Is there a possibility that glycine or arginine helps with growth hormone to help stimulate some of these things? Possibly. But I’ve never seen any science to back it up. So basically you have this protein that has a lot of testimonial. People love it, and yet you have the science says it’s absolutely awful. And so that’s kind of the bottom line.

Dr. Mark Hyman: Okay. Couple more questions and I’ll let you go. Because these are all things that people are asking all the time. In terms of exercise timing and protein intake. Can you talk about that? Because the protein study did review, especially as we get older, when we should eat protein in relation to when we exercise to get the maximum muscle building effect.

Dr. Don Layman: Let’s talk a little bit about exercise before we do that. So type of exercise for a healthy adult, that weight loss study that we talked about, basically we did five days a week of anaerobic, just sort of walking exercise, real moderate intensity and two days a week of resistance, which was basically yoga and stretch.

Dr. Mark Hyman: Wait, resistance was yoga and stretch?

Dr. Don Layman: Yeah. So the issue of muscle growth, muscle health and protection is stretch. Eccentric motion is actually more important than concentric. Stretch is important. A lot of great research back in the seventies about this and we’ve kind of forgotten. So if you’re trying to build muscle, if I’m wanting to be a football lineman, then you need to lift heavy weights. You need to lift weights 70% or higher of your maximum lift capability. But if you’re an aging adult just trying to protect your muscle, you’ll get a massive benefit just by doing yoga, just by doing stretch.

Dr. Mark Hyman: But you won’t get bulk?

Dr. Don Layman: You won’t get bulk, which a lot of adults aren’t looking for.

Dr. Mark Hyman: And you wouldn’t necessarily get definition?

Dr. Don Layman: You wouldn’t necessarily get definition. Definition would be partly muscle and partly fat.

Dr. Mark Hyman: I’m going to send you after this, and I’ll post it in the show notes, my picture at 40 and 62. I was doing yoga and running and I was like, “I did yoga, I don’t need to do anything else. That’s strength training.” And maybe it was, but I can tell you my body looks so different now and I’m like-

Dr. Don Layman: The obvious joke here is, please don’t.

Dr. Mark Hyman: I had my, okay.

Dr. Don Layman: I’m sorry, what exercise? What was your original question?

Dr. Mark Hyman: Well, my question was, what timing in relation to protein?

Dr. Don Layman: Oh, timing and protein. So all of that, what we did, we sort of started this ball rolling, is that when we were studying the leucine mTOR question, one of the things we know is that if you go into fasting, the longer you fast, you start down regulating protein synthesis. Not only at the initiation phase, but also at the transcription phase, fewer ribosomes, fewer messenger RNAs. So what we wanted was an acute catabolic event. So we did exhaustive exercise, and what we showed is exhaustive exercise causes a catabolic event in muscle. And what we showed is if you give protein right after exercise it causes recovery. People have run with that and said, “Well, you should have your protein post exercise.” Well, the research, what it actually shows is that’s probably only important when you first start. If you are an untrained individual who does an exhaustive bout, it will be catabolic. But if you’re well-trained in an event, it really doesn’t matter when you have the protein afterwards, other than you’re going to be catabolic until your next meal.
And so if your next meal is two hours or four hours later, if you want to go out in the morning and exercise before breakfast, that’s great. I tend to exercise sort of early afternoon. I’ll go out and exercise at two, I’ll eat again at seven. It doesn’t matter where it occurs if you’re well-trained.
If you’re starting a new training regimen, if you’re first two weeks of football practice in the fall, taking protein right after, that’s probably a good idea. It’ll reduce soreness probably, it’ll help you recover quicker before you have your next football practice in the afternoon. But as far as an average person, it doesn’t matter. All these jocks going to the gym with a bottle of protein and gulping I think is kind of humorous.

Dr. Mark Hyman: Interesting because because in the protein study, it did seem to say that it was important to have protein within an hour or two of working out for untrained individuals.

Dr. Don Layman: All those experiments are untrained individuals with maximum exertion maximum [inaudible 01:26:32].

Dr. Mark Hyman: I see. So if you’re kind of in shape already, you can kind of get your protein throughout the day. But what you’re also saying is that morning protein is essential. You’re in this a state of breakdown until you turn off the breakdown with the buildup by eating enough protein in the right quality in the morning,

Dr. Don Layman: I’m not took particularly hooked on, is that at seven in the morning or is that at 10:30? I don’t really care. So time restricted feeding, now you’re doing that to control calories. And so weight control, and that may be a more important issue than three hours earlier breakfast. So I’m okay with time-restricted eating. I’m not okay with intermittent fasting, but I am okay with time-restricted feeding. And that first meal, I try never to use the concept of breakfast because that implies a time of the day. I always say first meal. And if that first meal’s at 11:00 that’s okay.

Dr. Mark Hyman: Yeah. Interesting. Holy cow. We just went through so much in an hour and a half. I literally could talk to you for another three weeks nonstop. I have so many questions, but this is great. Maybe we’ll have you back for part two. Don, you really have laid a lot of the groundwork for the science around this. And there’s a lot of opinions out there. There’s a lot of propaganda. I would say there’s a lot of misinformation. People are very confused.
But I think the take homes here are really clear. We need to have high quality protein in more than the minimum amount of the RDA, which is the minimum amount, particularly as we get older. And we need the right quality protein, which means we either have to have animal protein or we need to combine it with plant protein or we need to have special plant protein where it’s added processed plant protein, which I’m not a big fan of, and we need to make sure we exercise.
So these are really simple ideas, but they are profoundly effective. And I can tell you in just my own personal life, applying them has revolutionized my health in ways that I didn’t imagine. And thanks part to Gabrielle, who’s your student, who’s been hounding me for years to start strength training. And I don’t lift heavy weights, I just do bands and I travel with them everywhere. And that really seems to do the job for me.

Dr. Don Layman: And that’s the point I was making. It’s stretch. It’s not the amount of weight, it’s about stretch. And I hope everyone walks away realizing, I don’t think we said anything that extreme. We’re talking about kind of middle of the road sort of diets. We’re not talking about keto carnivore, we’re not talking about vegan. We’re talking about sort of in between. People can exist at the extremes but the average person really is going to be best off at sort of this middle ground where they’re protein centric, they’re protein conscious, and they keep their calories under control. And that’s really the issues.

Dr. Mark Hyman: Great. Fantastic, Don. And people want to learn more about Don you can follow him on Twitter at Don Layman, D-O-N L-A-Y-M-A-N, and on his website Thank you, Don, for all the work you’ve done for decades to get us to where we understand a little bit more about muscle. And I would sort of close by saying, I think muscle is the currency of aging, and if we don’t protect and learn how to take care of our muscle, we can maintain our cardiovascular health our brain health, but it is so key to all of that, and I think it’s just the neglected organ.

Dr. Don Layman: I agree. I think we sort of think it’s only for muscles, but it’s actually for all of us and it really is kind of the currency of aging. So great to be with you, Mark.

Dr. Mark Hyman: All right. Well Don, you take care and for those of you listening, love this podcast, share with your friends and family. Hopefully it will end some of their confusion. Subscribe however you get your podcast. Leave a comment, tell us what you’ve learned about your body and protein consumption and exercise, and we’ll see you next time on The Doctor’s Pharmacy.
Closing: Hi everyone. I hope you enjoyed this week’s episode. Just a reminder that this podcast is for educational purposes only. This podcast is not a substitute for professional care by a doctor or other qualified medical professional. This podcast is provided on the understanding that it does not constitute medical or other professional advice or services. If you’re looking for help in your journey, seek out a qualified medical practitioner. If you’re looking for a functional medicine practitioner, you can visit and search their Find a Practitioner database. It’s important that you have someone in your corner who’s trained, who’s a licensed healthcare practitioner and can help you make changes, especially when it comes to your health.

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