September 26, 2022
NUTRITIONAL BIOCHEMISTRY
#224 ‒ Dietary protein: amount needed, ideal timing, quality,
and more | Don Layman, Ph.D.
“We want weight loss, but we don't want people to lose any lean mass. Especially if
they're adults.” —Don Layman
Don Layman is a Professor of Food Science and Human Nutrition at the University of Illinois
Urbana-Champaign. He has spent the past 40 years investigating the role of dietary protein in
muscle protein synthesis. In this episode, Don describes how his decades of research have shaped his
thinking around protein, muscle, anabolic factors, metabolism, and more. He explains the
recommended dietary allowance (RDA) for protein: what it is, how it came about, and how it should
serve only as a guide for the minimum protein necessary for survival rather than as an optimal level
of protein intake. He provides an overview of the essential amino acids, explains the nuances of
animal versus plant protein, and provides insights for determining protein quality, absorption rates,
and how to best track your intake. He discusses the ideal timing of protein intake in relation to
resistance exercise, how protein should be distributed among meals, and how limitations in protein
utilization per sitting can impact those practicing time-restricted eating. Additionally, Don shares
results from his clinical trials, including how a high-protein diet fared in terms of fat loss, and
explains the differences in protein utilization between adolescents and adults and how the problem
of reduced efficiency of protein utilization in older adults can be overcome.
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The Peter Attia Drive
n: amount needed, ideal timin
We discuss:
Don’s background: from growing up on a farm to studying nutritional biochemistry [2:30];
Don’s philosophy on nutrition, muscle, and metabolism [6:30];
The controversial relationship between saturated fat and atherosclerosis [18:15];
The basics of protein and amino acids [25:45];
Origin and limitations of the current recommended dietary allowance (RDA) for protein
intake [32:15];
Protein sources: determining quality, absorption rates, and how to track intake [41:15];
Leucine, lysine, and methionine: three important essential amino acids [48:00];
The vital role of ruminant animals in the production of quality protein [53:15];
The differing needs and impacts of dietary protein for a 16-year old compared to a 65-year old
[59:30];
Consequences of protein deficiency in childhood [1:06:30];
Muscle protein synthesis: ideal timing, small meals vs. big meals, and more [1:12:45];
Protein needs of children [1:19:45];
How important is timing protein intake around training? [1:24:15];
The role of leucine in fatty acid oxidation by muscle [1:28:15];
High protein diets for fat loss: Results from Don’s clinical trials [1:31:30];
Influence of industry funding on nutrition studies [1:43:45];
Don’s thoughts on plant-based and synthetic “meats” [1:48:45];
Problems with epidemiological studies of dietary protein [1:56:30];
More.
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SHOW NOTES
*Notes from intro:
Don Layman is a Professor Emeritus of Food Science and Human Nutrition at the University
of Illinois Urbana-Champaign, where he served as a member of the faculty, as well as the chair
of Foods and Nutrition, the Director of Human Ecology and the Associate Dean of
Agriculture
He earned his bachelor’s and master’s degrees in Chemistry at Illinois State University and his
doctorate in Human Nutrition and Biochemistry at the University of Minnesota
His research has focused on muscle development, protein and amino acid metabolism, and
nutrition in the context of athletic performance, obesity, diabetes, and cardiometabolic
health
Don currently consults for many food industry companies, including Kraft, Nestle, Hershey,
the dairy council, the egg board, and the beef board
In this episode, we talk about Don’s background, his interest in protein, muscle, insulin, and
anabolic factors in general
We explain what the RDA (recommended dietary allowance) for protein is
How it came about
How it’s clearly being misunderstood by people as a recommended amount of protein
versus a barely minimum protein amount for survival
We talk about the nuances of animal versus plant protein
We talk about the difference in protein requirements between children and adults, even
normalized to mass
And we talk about what happens to children who are protein deficient early in life
Then we look specifically at protein needs under various circumstances
For example, what’s the maximum amount of protein that can be consumed and used
in one sitting which will still contribute to muscle protein synthesis
We talk about the ideal timing of consuming protein throughout the day and around exercise
We talk about the importance of protein quality when looking at how much or how little a
person consumes
Then we talk about how these things change as you age
Don’s background: from growing up on a farm to studying nutritional
biochemistry [2:30]
Peter has heard a lot about Don over the past couple of years from their mutual friend Layne
Norton, who suggested they get together and go deeper down this nutritional pathway
Nutrition is Peter’s least favorite subject only because he’s so tired of the religious aspect of
nutrition
He enjoys talking about nutrition through the lens of biochemistry
Don was interested in biochemistry first
Studying organic chemistry just seemed so boring and esoteric
With nutrition, he could actually apply biochemistry to things people were interested in
What was it like growing up on a farm in Illinois?
His dad lived to 97 and his mom to 102
It was great, he was born in the ‘50s
This was a time when agriculture was very poor in the US
He learned about animal growth and reproduction
He leaned about growing corn and soybeans
He was very interested in food, he always had an interest in science, and this evolved to be a
natural marriage
He grew up in a small town; his school had about 400 people in it
In college Don first studied biochemistry and organic chemistry
This was the serendipity of how he got into nutrition; he didn’t know anything about it
He first went to Illinois State University to study chemistry
He realized quickly he had no aptitude for inorganic chemistry, but he understood
biochemistry pretty well
This was during the Vietnam War and he was scheduled to go into the military
He was totally unemployable
So when the university offered him a graduate assistantship, he took it and got a master’s in
biochemistry
His mentor at the time said, “You really have a knack for this nutrition part of it. Why don’t you do a
PhD?”
He ended up at University of Minnesota doing a Ph.D. in nutritional biochemistry and fell in
love with all of it
There was no grand plan, but it fit his background of agriculture, foods, sports nutrition
He fell into a group that was doing muscle metabolism and it just all fell together for him
Was Ancel Keys at the University of Minnesota at that time?
No, he had left, but his legacy was there with Henry Blackburn, Ivan Frantz, and some of
those individuals
Don got that background while he was there and it certainly invested a lot of his early
thinking of nutrition
Layne Norton, who you’ve talked with before, has talked about how our thinking of nutrition
evolves; “mine certainly has evolved”
Don’s philosophy on nutrition, muscle, and metabolism [6:30]
What was your underlying philosophy of nutrition circa 1975, when you were doing your
Ph.D?
His earliest thinking about nutrition involves his interest in animal growth and sports
nutrition
Very early he developed the philosophy that nutrition was really about two tissues, the brain
and skeletal muscle
If those two tissues were healthy, you were going to live a pretty good life
Everything else is regulatory‒ the liver, the heart, the kidney, the gut
Everything else adapts to your environment, but you have to focus on those first two
Don says that “if you tailor your nutritional requirements around that thinking you end up with a much
more sensible approach”
He coined the concept that his colleague, Dr. Gabrielle Lyon and he always use‒ muscle
centric nutrition
If you keep muscle healthy, you’ve got a good shot at avoiding obesity, avoiding
diabetes, avoiding cancer, etc.
“If you keep muscle healthy, you’ve got a good shot at avoiding obesity, avoiding diabetes, avoiding cancer,
etc.” —Don Layman
Details about muscle
Peter notes that muscle is our largest sink for glucose
75-80% of our glucose storage capacity exists within skeletal muscle
Muscle is also an early depot for excess adipose tissue
Once we start to let little droplets of fat accumulate within muscle cells, it leads to this
process of insulin resistance
This creates a problem in that it makes it harder for muscle to accept carbohydrates
This leads to hyperglycemia and ultimately diabetes
How Don formulated his thinking about muscle
What Peter said is correct but he thinks about it differently
Muscle serves 2 functions
1 – Mobility, functional mobility is critical
Most people live to age 65; beyond that most people actually die from some form of
immobility
This can be falls, breaking something, hospitalization
2 – Metabolism, muscle is a primary site for insulin activity
Peter mentioned glucose storage but he looks at it more in terms of glucose utilization
and fat utilization
Blood glucose and blood lipids are heavily dependent on muscle metabolism
Obviously the amount you eat makes a difference
But the actual level is heavily dependent on your muscle metabolism
Don notes, “You commented about insulin resistance being associated with fat, actually insulin causes
insulin resistance”
If you chronically elevate insulin for too long, that is the definition of type 2 diabetes
Causality of type 2 diabetes
Peter spoke with Jerry Schulman on the podcast about 2 years ago
His paradigm was the accumulation of diglycerides within actual myocytes, not
interstitial or in between
The actual accumulation of lipid within muscle cells impairs insulin signaling resulting
in decreased PI3K activation
This removes the signal needed to move the glucose transporter GLUT4 to the
cell membrane (and glucose is not taken into the muscle cell)
Hyperinsulinemia is effectively the first way you can externally measure insulin
resistance
Is this in line whe what you’re saying?
Yes and no. Don agrees Jerry Shulman is great and he follows his research a lot
In biochemistry you can create models that give negative feedback
Schulman is correct that diacylglycerol or ceramides (lipids/ fats) will feed back to the insulin
receptor, GLUT4 transport, and cause insulin resistance
That is a fat centric philosophy, that fat causes all the problem
You can do the exact same thing with glucose
Too much glucose will also inhibit the insulin receptor and cause that same exact
feedback
It doesn’t cause accumulation of ceramides or diacylglycerides
The question becomes‒ Which one is more likely to be physiological?
Is insulin resistance due to people eating 350 grams of carbs per day?
Or people eating 90 grams of fat per day?
The Randle hypothesis claims that fatty acids (diacylglycerol) cause all the problems
Bob Wolfe did this experiment with stable isotopes and showed it’s the reverse
Fatty acids are not inherently toxic but glucose is
Glucose has its own disease, diabetes
When you eat excess carbs, you must get rid of them
Carbs absolutely have to be disposed of in the next 2 hours
Fat can hang around for much longer, it’s not that toxic to the body
The body always wants to have a certain level of free fatty acids in the blood because
that’s fuel for the heart
What about the ability to turn excess glucose into fatty acid via de novo lipogenesis? Doesn’t
that happen quickly enough to alleviate some of the toxicity of acute hyperglycemia?
It doesn’t happen super quick
A lot of people argue how much de novo lipogenesis (fat synthesis) actually occurs
But when you get into requiring high amounts of de novo lipogenesis, now we start talking
about fatty liver
This is when you start seeing triglyceride problems
People who are actually doing a lot of de novo lipogenesis typically have elevated
triglycerides; that’s one of the first signs that you’re disrupting that flow
Triglycerides in general are there to recycle free fatty acids
Adipose tissue is always dumping free fatty acids out for the heart and other tissues
“The problem comes in when you start blending that with too many carbs and too many fats”‒ Don
Layman
First and foremost, calories are always the problem
You get in trouble when you have excess calories and you start rebalancing these
macronutrients
Peter adds, “There’s a very famous paper by Marc Hellerstein circa mid 90s, that demonstrates really a
very small amount of de novo lipogenesis taking place with carbohydrate feeding. I absolutely believe the
results of the paper, but I also think it’s a very narrow context and it’s not necessarily the context of an
overfed individual.”
He thinks our capacity for de novo lipogenesis (DNL) depends heavily on total energy
content or total energy balance
He thinks there is a scenario where in the Hellerstein paper you can feed a high
carbohydrate diet, but within the overall composition of a low energy diet (or a
balanced energy diet) and DNL is actually quite low
Conversely, you can feed a high carbohydrate diet in the context of a high energy diet
and we would probably see a much greater amount of DNL
Don agrees
Peter thinks the context matters
If were were describing this as a polynomial, the first order term is energy‒ how many
calories are coming in
That probably matters more than the ratio of carb to fat
Back to the Randle Hypothesis
Don always thinks of excess glucose (carbohydrates) as toxic
If the blood glucose level is high, it will damage every tissue from your eyes to your toes
You have to dispose of the glucose
Hellerstein’s study looked at an American diet (50% carb, 35% fat)
If you take in a 1,000 calorie meal or an 800 calorie meal, which one will result in more
fat synthesis?
The carbohydrate will get burned and the fat will go to fat
The body simply selects the easiest pathway
But if you switch that to a diet of 80% carb and 10% fat then you’ll see de novo lipogenesis
Jules Hirsch showed this and Jeff Volek also showed this
One of the interesting things is that when the body makes fat, the only type it can make is
saturated fat
Having a lot of saturated fat in the blood doesn’t actually come from eating fat, it comes from eating
carbs
Think of this in context of how much you’re eating
We burn around 100 calories per hour; that would be 2,400 calories per day
So in 2 hours you’re burning 200 calories
Everything else has to be stored
An average American meal is 400 to 1,000 calories; that means you have to store all of that
Is this an argument for spreading out calories more over the course of a day?
Absolutely not; there are 2 angles on that
1 – A theory in the mid 80s by Gil Leveille was that lots of small meals was good for less fat
deposition
This turned out to be an artifact of how he did the study
He showed that when animals made the adaptation to small meals, the animals didn’t
gain as much as if you adapted them to eating 2 meals per day
The artifact was, when an animal adapts to 2 meals per day, they go through a
starvation period and when they come out of a starvation period, they make more fat
Don redid the study with a longer adaptation period and found that reducing the number of
meals per day is actually thermogenically advantageous
You actually waste more calories
2 – The other aspect to consider is protein
Protein needs to be distributed at specific meals, and the distribution needs to be high
“Eating lots of small meals is a really bad choice for a lot of reasons”‒ Don Layman
The controversial relationship between saturated fat and atherosclerosis [18:15]
At the University of Minnesota, Ancel Keys is really famous for 2 things in the mid 70s
1 – His seven countries study
Published as a book in 1980, Seven countries : a multivariate analysis of death and coronary
heart disease
Summary from the University of Minnesota
The hypothesis now is a very fat centric view of the negative consequences of dietary fat
Specifically dietary saturated fat in the American diet
Especially as it pertains to ASCVD
2 – Starvation experiments
These were done on conscientious objectors, in the 40s
The results were published in a 2-volume book in 1950, Biology of Human Starvation
We learned a lot about starvation from these studies
How Don’s thinking evolved about saturated fat
When he got to Minnesota, he bought into the paradigm about the dangers of cholesterol,
saturated fat, and total fat
This is what was being taught
As he slowly started doing experiments, his thinking began to change
Early in his career he did a lot of fasting experiments with animals to look at composition
changes
He did malnutrition work in Northern Africa
He will always remember a seminar at Minnesota by Fred Kummerow about the dangers of
cooking oils and trans fats
Blackburn and Frantz just ridiculed him
They basically said, “This is the craziest thing we’ve ever heard. All these plant oils are
great.”
20 years later, we have banned trans fats from foods literally as the most dangerous fat
that you can encounter
Don remembers thinking, “Wow, people who have bought into this dogma aren’t necessarily
right, and we need to keep questioning it.”
The Minnesota Coronary Experiment
In 1973 Frantz completes the Minnesota Coronary Experiment
This is one of the most difficult studies for Peter to interpret
Chris Ramsden republished it a couple of years ago, based on all of the data from
Frantz’s study, plus data he never published
He also published one 16 years later in 1989, Test of effect of lipid lowering by diet on
cardiovascular risk. The Minnesota Coronary Survey
Don remarks, “I have posed this question to every friend of mine who is more steeped in nutrition than I
am. And I still don’t have a great sense of how to explain these results.”
The experiment was done in basically institutionalized patients
This might not be easy to do today for ethical reasons
It had the advantage of being well controlled
Patients were randomized into 2 groups; their total energy was identical as was the split of
macronutrients
1 – One group ate a diet high in saturated fat
2 – The other group at a diet high in polyunsaturated fat
The hypothesis being tested was‒ Is saturated fat intake leading to increased major adverse cardiac
events, heart attacks, and strokes?
The experiment ran for 5 years (1968-1973) and showed no difference
There was no difference in cardiac events, despite the fact that the group that was on the higher
polyunsaturated fat group did indeed have much lower cholesterol levels
This predated measuring LDL and HDL (subfractionation of cholesterol); they simply
measured total cholesterol
At the time there was some correlation between cardiovascular disease and total cholesterol
levels
At the extremes, that was certainly true
The results showed a significant reduction in cholesterol levels for those with a diet high in
polyunsaturated fat
The change in serum cholesterol for this group was -13.8% [decreased]
The dietary change in saturated fat for this diet was -51% [decreased] and for linoleic
acid (a polyunsaturated fat) was 288% [increased]
Peter notes, “Based on everything we know today, we would assume that much of that was in LDL
cholesterol, indeed being lower and non-HDL cholesterol. Yet there was no difference in events.”
“It’s become a very famous and unfortunate story in nutrition research and that Frantz chose not to
publish it because he didn’t like the results”‒ Peter Attia
The results didn’t match his hypothesis, which was that the group on lower saturated fat would have
fewer events
Peter’s initial view of the Minnesota Coronary Experiment was that the intervention did not
go long enough
Maybe 5 years is not long enough to appreciate a difference
It was underpowered to see a benefit, if there was a benefit
In Ramsden’s analysis, you saw the opposite
He looked at some subgroups
Now you actually saw a higher incidence of coronary events in some of the people that
were consuming the high polyunsaturated fat diet
Peter can’t remember what the dominant oil was in polyunsaturated fat diet, canola or
safflower [it was corn oil]
Don’s interpretation of the Minnesota Coronary Experiment
Don points out that he is not a lipid expert
He did some research with Ivan Frantz when he was at Minnesota
Looking at the literature on saturated fat, it’s a very mixed bag
The people who believe the hypothesis have either delayed publishing it or said it could have
been wrong
They tried to find all kinds of excuses as opposed to believing the results
“There’s an old theory in science that if a theory is correct, it’ll get stronger over time. And if it’s not, it gets
weaker”‒ Don Layman
The total cholesterol theory has definitely gotten weaker and the saturated fat theory hasn’t held up
very well
Don’s Takeaway on saturated fat
First and foremost is calories
If you put excess saturated fat on top of too many calories, that’s probably a problem
But if you’re at or below your calorie needs, he doesn’t see any data to suggest that saturated
fat is a problem
If you’re committed to being obese, you probably ought to pay attention to the quality of your
fats
If your goal is to be lean and healthy, calories is what you should paying attention to
The macro distribution is your personal preference
The basics of protein and amino acids [25:45]
This is the macronutrient that Peter pays the most attention to
Many days he comes up short in protein intake, but he never goes overboard
Peter’s goals are to maximize muscle protein synthesis to preserve lean tissue for as long as
possible
How did Don become interested in protein?
This began during his master’s degree research
He was working with Arlan Richardson who was an expert in aging and was studying agerelated changes in protein synthesis and protein turnover
They discovered changes in mRNA over time, that the poly-A-tails on mRNA were getting
shorter
This lessens the ability of ribosomes to bid the mRNA and results in lower protein
synthesis
This theme of efficiency (or change) of protein synthesis over time is a theme that runs through all of
his research
When he went to Minnesota, he became focused on muscle protein
One of the first things he learned in graduate school is we don’t really have a protein
requirement
We have a requirement for 9 essential amino acids and organic nitrogen
This translates into the fact that we can make 11 amino acids and 9 we have get
from our diet
Don says to think of protein as a “vitamin pill”
We don’t have a daily requirement for a vitamin pill
We have a requirement for 12 vitamins inside the pill
We don’t actually have a daily requirement for protein, we have a requirement for nine or 20
amino acids inside of it
In terms of protein requirement, we have a requirement for the 9 essential amino acids
These amino acids are essential building blocks for new protein
But every one of them has a metabolic role like
Leucine and mTOR or
Arginine and nitric oxide or
Lysine and carnitine or
Cysteine and glutathione
And all of those roles are vastly above the minimum that is detected for nitrogen
balance for the RDA (recommended dietary allowance)
When we think about vitamin C, we know there’s a minimum RDA to prevent scurvy, but
people will take 5 or 10 times that during COVID for immune response
But we resist thinking that way about amino acids, and it’s exactly the same
Amino acids 101—Structures common in metabolism
Most people understand what glucose looks like (see the figure below)
It’s a 6 carbon ring and each one has an oxygen and hydrogen on it
Figure 1. Structure of glucose.
Most people who have listened to this podcast have a decent sense of what a fatty acid looks
like (see the figure below)
It’s a long stretch of carbons
If it’s saturated, there are no double bonds
So it’s just littered with either 2 or 3 hydrogens depending on where it sits in the chain
You store them by putting 3 fatty acids onto a little 3-carbon glycerol backbone to make
a triacylglycerol (shown in the figure below)
Figure 2. Fatty acids are stored in the form of triacylglycerol. Image credit:
OpenStax Biology 2e
Amino acids
Most people understandably have less clarity around what an amino acid is
The figure below shows the generalized structure
We’ve already alluded to the fact that there were 20 of them
They differ in their side chain (R-group)
9 of them we can’t even make, and if we were deprived of these things we’d be dead
An amino acid looks a little bit like a fatty acid, it has a carboxyl end connected with a carbon
and it has a nitrogen end
Figure 3. Generalized structure of an amino acid and 2 examples, glycine and
tryptophan. Image credit: OpenStax Biology 2e
When we eat protein, we get these amino acids in a string, but we totally digest them down to
individual amino acids or maybe di- or tripeptides that we can absorb
They get to the blood as single amino acids for the most part
Then the body begins to reconnect them based on the messenger RNAs
Our DNA tells us how to reconnect them
And so we connect a carbon [carboxyl end] to a nitrogen [amino end] and we string
them together
Of these 20 amino acids though, they all have that acid [carboxyl] and nitrogen part, but they
also have a side chain, ranging from very simple one like glycine (with just a hydrogen), to
ones like tryptophan that have a big aromatic part to them
Shown in the figure above
All of the 20 amino acids are different, they go into proteins and form different structures
The DNA tells us how we put them together
Proteins can be simple like insulin with 51 amino acids
Or they could be like myosin with thousands of amino acids
And then every protein in the body has a different turnover rate
Some of them, like insulin, might last 15 minutes
Some of them like myosin or collagen might last 250 days
But beyond that building block structure, every amino acid has other kinds of structures
It might be like lysine where part of it becomes the molecule known as carnitine (see the
figure below), which is needed for fatty acid metabolism
Figure 4. Lysine and carnitine. Image credit: OpenStax Biology 2e and the Linus
Pauling Institute
Or it might be the nitrogen off arginine that goes to nitric oxide for vessel restriction (see the
figure below)
Figure 5. Arginine and nitric oxide. Image credit: OpenStax Biology 2e and Wikipedia
Or it might be cysteine, which goes to part of glutathione (see the figure below)
Figure 6. Cysteine and glutathione. Image credit: OpenStax Biology 2e and Wikipedia
Don’s favorite is leucine, this is the signal that really got him interested in protein (see the
figure below)
In metabolism, leucine is a signal for muscle protein synthesis
Figure 7. The amino acid leucine. Image credit: OpenStax Biology 2e
So all the amino acids have this building block function for making proteins where they get strung
together, but they also have other metabolic functions
Origin and limitations of the current recommended dietary allowance (RDA) for
protein intake [32:15]
When Peter looks at his patients and evaluates their nutrition, almost without exception, he
comes to the conclusion that they are not getting enough amino acids based on how much
protein they are consuming
How the recommended dietary allowance (RDA) came to be
The RDA is a recommended dietary allowance
The argument is that for all RDAs we test a population and come up with an average number
and then for a safety factor, which on average 50% would be deficient
We add a safety factor of 2 standard deviations, which supposedly would be adequate
for 97.5% of the people to prevent any signs of inadequacy
But that also means 2.5% of the people are actually deficient at that level
Where does the RDA come from?
Consider the history of how we begin to evaluate protein needs
It all came out of animal sciences back in the early 1900s, before we even knew all the
essential amino acids
Farmers wanted to know how to get animals to grow best
They developed protein quality scores and things like that to track much growth they saw for
what they fed the animals
How much nitrogen was deposited for how much was fed?
So these were all rapidly growing animals
From this developed a concept of nitrogen retention
That we’ve now translated into what’s called nitrogen balance
And that’s how we determine the protein requirement
All of the concepts were developed for growth where nitrogen balance was positive
You could measure a change over time
Now that we have tried to start applying that to non-growing adults, it gets a lot more vague
So it’s important to recognize that what we think about protein requirements is developed from
nitrogen balance, where you measure all of the nitrogen you’re eating (which you can do pretty well),
but then you have to measure all of the nitrogen you’re losing (which we’re really bad at), and we call
that nitrogen balance
How nitrogen balance is calculated in a human
Start with the front end, how much nitrogen is eaten in food
You take a bunch of food and do a chemical analysis to measure the nitrogen and then
multiply by a factor of 6.25
This is an assumption that any protein contains 16% nitrogen (which isn’t always true)
You’re measuring nitrogen not really protein
Nitrogen is also in nucleic acids
You’re measuring nitrogen in anything and calling it protein
So there is some error on the front end
On the back end, we are going to try and measure losses
The primary loss of nitrogen in the body is into urine as urea
So that’s pretty easy to measure, you can collect that
Second would be the stool
There are also things like sweat, skin loss, hair loss, and respiratory nitrogen ammonia in the
breath
And those are all incredibly vague
“Everyone who knows nitrogen balance says that nitrogen balance underestimates requirement”‒ Don
Layman
The RDA comes from short-term studies and what you find for most people
These studies were done with college-age students, right at the end of their growth
They are short, 7-day studies
Don points out, “Those of us who study protein have gone beyond that and said, well, nitrogen balance is
one outcome, but like the vitamin C argument, there are other outcomes based on amino acid metabolism
that may be more important than minimum nitrogen balance”
Don’s summary: “We now know that protein handling (the efficiency) goes down as we get older. So now we
have much higher requirements that most of us talk about for adults.”
Peter’s takeaway: The reason we all agree that standard nitrogen balance underestimates the
requirement is, it’s easier to measure the sum of the ins than the sum of the outs
Don adds, “Chances are you’re significantly underestimating the outs”
Peter recalls as a surgical resident, times where they did a nitrogen balance on patients who
were on long term TPN (total parenteral nutrition) in the ICU
They had to be fed all of their nutrition through a central line, a very complicated
feeding
The nutrition team would come in for a consult and do a nitrogen balance
They literally put a tent over the patient to create a laboratory environment to
calculate nitrogen balance
This is very important for a critically ill patient that is in a hyper-catabolic state
If you’re trying to create an anabolic state in that person to keep them alive, it’s
imperative that you understand how much nitrogen they have or how much nitrogen
that they require
So the simple idea of “I’m just going to tell you how much protein you’re eating and I’m going to
measure the nitrogen that’s coming out in your urea,” that’s just not going to cut it
Don agrees, that’s just too simple
Currently, a lot of those studies are simply done with a factor
They don’t put them in a tent or whatever, they just measure urea in urine and
everything else is just sort of 1.3
So obviously we’re perpetuating an error based on ignorance
How do you use isotopes to determine what’s happening with the nitrogen?
For the listener who might be lost as to why we’re talking about nitrogen, proteins/ amino
acids have nitrogen while carbs and fats don’t
So this is where we can really speak to the source of the nitrogen
Additionally, as we mentioned, anything with a nucleic acid is going to have nitrogen as
well
But the majority of nitrogen comes from proteins in food
Carbs and fats are energy sources, they have carbon-carbon bonds that provide energy
whereas amino acids have a very different purpose and structure
That nitrogen is part of what makes amino acids different
Peter’s takeaway:
We consume carbohydrates virtually exclusively for their energy content
Fat, mostly for its energy content
There is some structural importance that comes with fat and cholesterol
In contrast, you don’t want to be consuming protein for energy
Don adds a caveat, “There might be reasons that people are hypersensitive to carbohydrates where
taking in more protein (beyond what you might actually need for protein metabolism) might be a
substitution for carb calories”
Protein sources: determining quality, absorption rates, and how to track intake
[41:15]
How many of the 20 amino acids are in steak?
If you’re looking at animal source proteins, whether it’s meat or eggs or milk, basically all of
the amino acids that a human would need are in those
In meat, all the amino acids are in the right balance
We have basically the same amino acids, the same protein
But every protein has a little different balance of essential amino acids
Dairy proteins
Dairy proteins are something we can fractionate because they’re all water soluble
So we know a lot about alpha-lactalbumin versus lactoferrin and lactoglobulin etc.
We know that a lot of differences about amino acid compositions of individual proteins
Animal protein
We typically think of meat as
1 – Mammals, beef, pig, stuff like that
2 – Bird protein, mostly chicken
3 – Fish protein
And then you have eggs and dairy
The first 3 are exactly the same for a protein, “So whether it comes from a cow or a pig or a chicken or
a fish muscle, protein is still muscle protein”
How do we think objectively about the quality of a protein?
Isn’t there an efficiency of that protein versus tofu versus soybean versus price all the way down to lower and lower
protein density foods?
Protein quality is something Don thinks about a lot
He’s working with a group now to reinvent how we think about that
What he thinks Peter is referring to is protein quality in a sense of PDCAAS or DIAAS
(protein digestibility corrected amino acid score or digestible indispensable amino acid score)
We realize that when you look at a protein, there are 2 factors that go into a protein quality
score
1 – What’s the composition of those 9 essential amino acids?
2 – What’s its bioavailability? (how well do we digest it and absorb it)
With animal proteins and most isolated proteins, even soy protein isolates, the digestion and
absorption is pretty close to 100%
Digestion and absorption is usually 95% or higher for all animal proteins
For plant proteins it is less, maybe only 60-70% available because we can’t digest the fiber
proteins are attached to
You need to realize that in a plant, the protein is there for the purpose of the plant, and
it is attached to fibers
Fibers are structures, plants have proteins attached to the leaves and the stems and the
roots and the flowers and the seeds
When you eat plants in a raw form, only 60-70% of the protein is available because we
can’t digest the fiber
We can determine that a whey protein isolate is 20% better than a soy protein isolate on the
basis of its essential amino acids
Or we can compare a wheat protein (wheat bran) and realize that it’s only 40% available
Don points out, “If you look at wheat bran on a cereal box and say it was a wheat flour; and it says
there’s 4 grams per serving, there’s actually less than 2 that you can actually absorb”
This makes it hard to compare different types of foods and hard to build a meal that way
We can say whey is better than soy
That’s okay if you’re only eating those 2 foods
What happens when you start putting them together?
This is why Don is working with a group trying to build a pretty quality score that is based on 3 amino
acids (lysine, methionine, and leucine), which in his opinion are the key markers for adult health
Peter’s takeaway: “You could brute force your way through life by looking at every single thing you eat and
trying to figure out the DIAAS score for its protein. Okay. I’m about to have a rib eye; that’s going to be about a
96% DIAAS. I’m going to have my soybeans over here; that’s about an 80% DIAAS. I’m going to have my whey
isolate; that’s 100% DIAAS. I’m going to have my shredded wheat; that’s a 40% DIAAS. That’s a tough way to go
through life because you can’t just add up the protein.”
Don agrees, they’re not truly additive
You can’t really figure that out
The average person doesn’t even have that data
If you go into the USDA database with 7,000 foods, there are 4,000 that actually have amino
acid scores
And of those, there’s probably less than 300 that have DIAAS scores
And so you can’t put it together
Moving forward to allow better tracking of protein
This is why Don is working to develop a system that allows people to get better at tracking
protein
If you look on a label on a package and you see again, a wheat cereal that says it has 4 grams of
protein
That’s a nitrogen analysis times 6.25, remember all the problems discussed
And then if you look over at another column, it’ll say daily values, almost no label has
daily values for protein, because that would require a PDCAAS or DIAAS score, and
nobody has them
So that 4 grams [of protein in wheat cereal}really would translate into less than 2, but nobody’s being
told that
DIAAS is the digestible indispensable amino acid score
A lot of people are focused on digestibility
Don has a big problem with the amino acid scores because they’re incredibly low
They’re established by the World Health Organization and FAO
They are really designed to prevent malnutrition in Africa where we know from our
Institute of Medicine, that the essential amino acid scores should be much higher than
that
We mentioned stable isotopes a little bit ago
We know from stable isotope studies show that all those FAO amino acid scores are too low
And so that’s part of the equation that we’re not telling people
Leucine, lysine, and methionine: three important essential amino acids [48:00]
Peter’s takeaway: “What you’re offering is an alternative to people living in spreadsheets to calculate how
much actionable indispensable amino acid they’re getting is. What if we make this easier? And you focus on the
actual content of three amino acids. So we’re going to take a subset of essential amino acids.” Leucine, lysine,
and methionine (3 of 9 essential amino acids)
Figure 8. Leucine, lysine, and methionine. Image credit: OpenStax Biology 2e
If you make sure you get enough of those (leucine, lysine, and methionine) with each meal, the rest will
take care of itself
Figure 9. Essential amino acids for humans that must be obtained in the diet.
The current amino acid scores (DIAAS) are too low
Secondly, they’re not scoring apples to apples; they’re scoring apples and oranges
For example, if you look at the soy deficiency, all legumes like soy or pea are deficient in
methionine
If you score that against whey, the limited amino acid in whey is histidine
No one has ever shown histidine to be a limiting amino acid in an adult, it is a limiting
amino acid in children and babies
So this is like comparing apples to oranges; it’s not fair
If you compare methionine to methionine, it’s not 20% higher, it’s 250% better when
comparing soy to whey
Comparing across these 3 essential amino acids allows for an apples-to-apples comparison
These 3 essential amino acids (leucine, lysine, and methionine) are actually likely to be
limiting where no one has ever shown histidine or phenylalanine to be limiting in an adult
So why do we consider them limiting?
Leucine turns on mTOR
Listeners of this podcast are no stranger to leucine because we’ve had David Sabatini and
Matt Kaeberlein on and they have gone deep into the weeds on mTOR
One of David’s postdocs discovered the leucine sensor on mTOR
Now we know unambiguously that leucine is an amazing trigger for mTOR
People listening may be confused‒ if rapamycin is good and rapamycin inhibits mTOR, how
can leucine be good if leucine turns it on?
The difference is chronic activation
Sometimes you want mTOR on, sometimes you want it off
When we’re talking about eating, you want to be able to turn on mTOR for muscle protein
synthesis
How this relates to how often you eat
There is the issue of mTOR and whether it needs to cycle on and off
Not only does leucine turn it on, but so does insulin (probably the worst-case scenario)
People who eat a lot of small carbohydrate meals continuously activate mTOR
A lot of animal studies back this up
What you want is to use specific meals with the right amount of insulin to active muscle-centric
mTOR
mTOR is in every tissue
You don’t want to continuously activate mTOR in the liver or some other tissue
This is where confusion arises
People ignore the fact that insulin is the biggest trigger in other tissues where leucine a
very unique trigger in muscle
Practical applications of tracking leucine, lysine, and methionine
We know why leucine matters
Why would raising the level of methionine and lysine to the level of leucine become a great proxy for overall
protein load?
If you look at limiting amino acids in food, lysine is always limiting in grains
That’s a major consideration in determining the minimum amount to feed animals
Lysine is probably limiting for protein synthesis
Lysine is in carnitine and some other things, but it’s mostly needed for protein synthesis
We need 3.4 grams of lysine per day
We probably need a little less than 1 gram of methionine per day
Methionine is part of what we call the one-carbon pool
We need methionine to:
Make and repair DNA
Make and repair RNA,
Make taurine (downstream)
Make the non-essential amino acid cysteine
Make the oxidant glutathione
Methionine is one of the most limiting amino acids and it’s limiting in all legumes
Think of soy, peas, and lentils
We think of these as higher quality protein (they are), but they’re still limiting in
methionine
Natural sources of food high in methionine
Eggs are quite high in the sulfur amino acids (which are methionine and cystine, see the
figure below)
But all animal products are adequate in them
And basically all plant products are pretty low in them
Figure 10. Sulfur amino acids. Image credit: OpenStax Biology 2e
The vital role of ruminant animals in the production of quality protein [53:15]
Peter asks about animals like cows that are quite muscular but eat basically just hay and
grass‒
Does this speak to the incredible volume of plants they have to chew to make sure they’re getting enough
methionine, lysine, and leucine to be as anabolic as they are and produce so much muscle?
What volume of total protein in the form of grass and hay do they need to get a sufficient amount
of those muscle building amino acids?
Don replies that this brings us into a sustainability argument
Cattle ruminant animals are a very important part of the food chain
Their stomach is full of bacteria, and the only place essential amino acids come from in life is
bacteria
Our primary source of essential amino acids in nature is bacteria on the roots of plants
So bacteria on the roots will take in nitrogen and make all amino acids
This is why we fertilize our garden with nitrogen
Bacteria will take that inorganic nitrogen and form organic means that can be made
into proteins in the plants
The problem with plants is that they don’t have the same balance as we need
Don points out, “The beauty of a ruminant is they can take a plant and they can digest it, and the
bacteria will then rebalance all of the amino acids, they’ll capture inorganic nitrogen, and they make the
essential amino acids that mammals need and they concentrate it for us”
Teleological perspective
One argument is humans evolved by being able to use more concentrated protein
If we just ate plants, it’s hard to get enough essential amino acids
But if the ruminant an animal can actually digest all of that and form it into
appropriate amino acids….
So basically for every 60 grams of plant-based protein the animal eats, they’ll make 100
grams of essential amino acid balanced protein
This is why ruminants are called upcyclers
Whether it’s in dairy or meat (cow, goat, sheep, deer), all ruminant animals upcycle by eating grasses
and produce great quality protein
And no other animal can do this
Peter asks, “The bacteria are obviously the engine of that upcycle, but you can’t make nitrogen out of
nothing. So you’re saying…?”
They’re making protein out of nitrogen; they’re getting inorganic nitrogen from plants
Ruminants are able to increase the value of non-amino acid nitrogen, plus they capture
the nitrogen in protein form
Peter has never heard of this phenomenon and asks, “Are they also disproportionately creating
amino acids that weren’t necessarily there in the plant?”
That is exactly what is happening
Bacteria/ flora in the cow will produce methionine or lysine
They can basically take glycine (a non-essential amino acid) and make it into any amino
acid
One supplement you actually feed cows is urea and they can make it into methionine or
leucine or lysine
Humans excrete nitrogen waste as urea in the urine
Peter finds this fascinating and notes, “Now we’re venturing from nutrition into religion, because
there’s certainly a group of people who would argue that we should not be eating any animal protein
whatsoever… A counterargument to that would be, it’s awfully difficult without these animals to get
adequate amino acids.”
Don thinks of it as a biochemist and someone who grew up on a farm where they raised cattle,
pigs, corn, and soybeans
He sees it as a life cycle type of thing
There’s no question that ruminant animals play a very important role in our food system, and
one, we can’t really replace
Don adds, “We can’t just idle millions of acres of grassland and pretend that we can grow avocados on
them or broccoli. Cattle basically spend a year of their life on basically nothing but grass. Sheep, and goats
are the same, but those are amazing contributions to our food system.”
Peter was completely unaware of this capacity to concentrate and almost up-produce both in
quantity and quality of amino acid
That’s a very interesting finding
He didn’t appreciate the role of bacteria
The differing needs and impacts of dietary protein for a 16-year old compared to a
65-year old [59:30]
What do we know about the assimilation of amino acids into new muscle tissue across people
of different ages?
Don mentioned differences in the efficiency of muscle protein synthesis between 20-year olds
and 60-year olds
Peter asks, “What do we know about a 20 year old versus a 60 year old who puts their muscle under a
progressive overload? They’re doing resistance training. They’re being provided with adequate amino acids,
and let’s assume they’re being provided with not just the right quantity but the right quality of amino
acids.”
Don begins with the need for protein turnover, “It’s important to recognize that whether you’re 16
or 65, your body needs to make nearly 300 grams of new protein per day”
Every tissue in the body is turning over
Some as fast as liver enzymes, where you replace every hour
For muscle proteins the half-lives is around 15 to 16 days
Every 30 days collagen turns over at about half-life of a hundred days
Which is why if you hurt your knee, it takes so long to repair it
But basically the body replaces literally every protein in it, about 4 times a year, that’s a
pretty remarkable number
We have to make 300 grams of new protein per day, but the average American intake is
around 80 grams or less (for women it’s 70 and for men it’s 90)
This means recycling is going on
For every new protein that’s getting made in the body about 6 out of 7 amino acids are getting
recycled
This feeds into the process of protein synthesis and protein turnover
In Don’s master’s degree he was studying age-related changes in protein synthesis
We now know that as you get older, the efficiency of protein turnover goes down
If you give a 16-year old a certain amount of protein they will have a very good response
A 65-year old may have 10% of that response or no response at all
Don’s summary:
We have learned, with the study of leucine and initiation factors and all of that, that if you
leucinegive an enriched source of essential amino acids, you can actually make the adult look
just like the 16 year old
So what we know is that the efficiency goes down, but the capacity to respond doesn’t
Current thought in the field is that if you have a dietary protein requirement that’s about
twice the minimum RDA (2 x 0.8 = 1.6 gram per kg), you can get the 65-year old to respond the
same as the 20-year old in terms of muscle protein synthesis
Peter recalls the earlier discussion of how it’s a slippery slope if you just focus on total protein
If a person says, “I’m 65 years old and I’m on a plant-based diet,” does their protein intake need to
be higher?
Don says this point is exactly right
We know is that most people who go to a plant-based diet, a vegetarian diet, decrease both
the quantity and the quality
If you’re on a plant-based diet you’ll need more protein, and that means you’ll have to have more
calories
What is the threshold?
If you have 100, 120 grams of protein per day, the distribution between animal and plant
probably doesn’t matter, because you probably have enough to cover it
But, if you’re only eating 50 grams of protein per day then it makes a big difference, you’ll
never catch up to your essential amino acid needs
A good target is somewhere between 50 and 120 grams of protein, it depends on what you choose
If you’re going to be plant-based, have 125 grams of protein per day and you’re probably fine
But you’re going to get in trouble if you’re going to be vegetarian and you think you’re going
to get along with 56 grams per day
Differences in muscle protein synthesis in a 16-year old compared to a 65-year old
What can explain differences in anabolic resistance as we age?
Thinking about the difference between the 65-year old and the 16-year old, there’s a huge
difference in androgen level between those 2
Peter finds it very interesting you can overcome anabolic resistance by eating a higher
amount of protein
What else explains anabolic resistance?
1st and foremost are hormones
When you’re growing, hormones are your friend; they are driving it
If you look at malnutrition in Africa, children will grow on really lousy diets
They may not grow as healthy, they may not live as long, but there’s a survival/
reproduction nature to that
Now consider healthy aging and the criteria are different
Don wants to live as long as his parents (near the century mark)
Let’s think about mTOR in that framework
There are 4 different signals that regulate mTOR
1 – We’ve mentioned leucine
2 – We’ve mentioned insulin
3 – An enzyme factor known as AMP kinase, which is energy sensitive
4 – Another molecule known as REDD1, which is stress sensitive, particularly to
resistance exercise
So these are 4 different things the individual balances
Hormones that are dominant to drive growth when you’re young are insulin and IGF-1
Insulin is a growth hormone
When you stop growing at 25, it ceases to have an effect on protein synthesis and
muscle
So now the whole thing shifts to protein quality
Protein quality is not nearly as important when the system’s dominated by hormones
As we get older, we can buffer that loss of the hormones by higher quality protein, mostly
leucine, and resistance exercise
That’s the way you have to think about the change in efficiency that occurs with aging
Consequences of protein deficiency in childhood [1:06:30]
When Don got interested in studying protein, he learned from the godfathers in the field‒
John Waterlow, Joe Millward, Peter Garlick, and Vernon Young
He got involved with some international malnutrition with a US International Agency for
International Development (USAID) project in Morocco
The led to animal studies to look at malnutrition and recovery
He found that malnutrition/ starvation insults early in life would stunt muscle development
It limited DNA development and cellular development
It stunted lean mass in children and in animals
When this happened, the individual as an adult was always predestined to have low lean body mass and
high body fat (obesity)
“That was really the origins of how we started thinking about muscle-centric health”‒ Don Layman
If the muscle didn’t develop right, if it wasn’t metabolically correct, you were predestined to
develop other things
Don and Dr. Gabrielle Lyon put this concept together in muscle-centric health
What is the mechanism behind this phenomenon?
When you look at children in places like Africa, who are really malnourished, at first glance
you think, “Why are their bellies so big if they’re malnourished?”
This is due to extreme kwashiorkor‒ edema and enlarged liver caused by severe protein
malnutrition
Childhood malnutrition causes 2 things
1 – Marasmus, which affects the skin and bones
2 – Kwashiorkor, which causes an inflated belly
Kwashiorkor is disproportionately caused by poor protein in the diet
That leads to changes in water balance and edema
It appears to be due to an imbalance in the protein to energy relationship
The quality of protein is lacking; they eat these starchy porridges that are probably
totally deficient in lysine and methionine
Marasmus is caused by a deficiency in total calories (protein and everything)
What is it about this critical window of development, where this protein deficiency makes it
very difficult for them to put on lean mass later in life and creates a propensity for adiposity?
Don did some research on this back in the late 70s, early 80s
Muscle is a very unique cell structure
Muscle fibers are multinucleated, unlike a liver cell which has a DNA/ one nucleus in
each cell
Muscle cells have what are called satellite cells around them
So as the original fiber begins to develop, the satellite cells will put DNA (these nuclei)
into it
They determined that each DNA has a certain amount of protein it can handle
The DNA ultimately determines how big your muscle can get
They determined if the insult occurs late in pregnancy, early in lactation, you stunt these satellite cells
and you don’t develop enough DNA, so the muscle is always limited in its potential size
Peter was aware of the propensity for adiposity later but was not aware of the limitation in
lean growth
This is really a double whammy
Does this cause lifetime sarcobesity (loss of muscle mass and obesity)?
Yes
This decreases lean mass and decreases metabolically active tissue such that minimal calories will
deposit fat
Do you think some of this problem is going to happen (to a lesser extent) in developed
nations like the US?
In the US it would be hard to imagine a child developing kwashiorkor
But clearly there are kids in the United States that are disadvantaged enough that they’re not
going to be exposed to high enough protein in either quality or quantity
Don thinks it’s possible and worries about the advocacy of plant-based diets
New York City is taking animal proteins out of school lunch
“We’re conducting a public health experiment without actually having any knowledge of that. I think that’s
frightening.”‒ Don Layman
The issue is public school lunches, nursing homes, daycares
These are all under these federal guidelines
We’re diluting out the quantity and quality of protein at the same time with no knowledge of
what that’s really going to mean
Muscle protein synthesis: ideal timing, small meals vs. big meals, and more [1:12:45]
One of the challenges Peter has with patients is when they get into a very heavy regimen of
time restricted feeding
The idea is they limit the amount of time they eat but don’t place any limits on what
they eat, how much, or what they’re eating from
It certainly is an effective way to reduce calories
Peter has seen in people who adopt a very narrow feeding window (1 meal a day) for 6 months,
they disproportionately lose lean tissue
The diagnosis here is pretty straightforward‒ they clearly reduced energy intake but they
probably reduced protein intake too much
So body composition actually got worse, despite the fact that weight went down
Can you eat all of your protein in one meal?
Hypothetical person‒ is very active, they are going to eat 3000 calories in 1 sitting
Peter asks, “Even if I was able to eat 150 grams of protein in one sitting, is it clear that my body will get the
benefit from that, that it would if I ate 50 grams three times a day?”
Don replies, “It’s quite clear that you won’t get a benefit, that there is a limit”
“Think about the body as muscle versus everything else”‒ Don Layman
There is a lot of data now that muscle can handle protein meals for an optimum anabolic
response between 25- maybe 60 grams before you start getting into distribution
One of Don’s pet peeves in nutrition is when people refer to protein as a % of calories
Protein is not a % of calories
Protein’s an absolute number
You need to decide on what you’re going to build your diet around
Back to the hypothetical person‒ 150 grams of protein
Protein requirements are an absolute number so if your calories go down, your protein intake should
remain the same
For example, if 75-year old woman’s calories go down to 1200 calories/day, she still has a 100
gram per day protein requirement
So now her protein needs are 35-40% of her calories
When people are doing weight loss, it’s important to remember that protein requirements are
an absolute number and not a % of their daily calories
It’s common for people to say the diet should be 30% fat, 50% carbohydrates, and that leaves
15% for proteins
You have to think about protein first
As far as distribution of protein, his research shows that “the most critical meal of the day is the
first meal of the day”
When you have had an overnight fast your protein synthesis is down and that mTOR signal molecule is
down regulated (it’s inhibited), and until you have enough leucine (around 3 g, which translates to
about 30 g of protein for most people), your muscle stays catabolic
So you’re continually breaking down protein
Don thinks that’s a significant aspect of aging, that people have lower and lower protein, they
don’t eat protein at breakfast
And we know the efficiency is going down in the first place
Don’s recommendations
We want to front load protein in the day
We want at least two meals that are well above 30 g of protein
He always has people shooting for 40/45 g at the first meal, and another 45 at their last meal
And then in-between, if we’re talking with people who are…
An elderly woman trying to maintain minimal muscle, I’ll concentrate on those 2 meals
Somebody who’s trying to lose weight‒ concentrate on 3 meals because he doesn’t want
them getting hungry
Someone who’s trying to build hypertrophy (be a muscle builder)‒ concentrate on 4
meals
For the question of, “How many meals per day do I make anabolic and muscle? And by anabolic, I’m
thinking 35 grams or more.”
The data show for absolute certain that the first and last meal are absolutely important
Don would be hard-pressed to find a study where anybody’s ever looked at lunch
The reason an anabolic person needs 4 meals
1 – The leucine effects on mTOR signaling for muscle protein synthesis
2 – To get enough total protein per day
So if you need more protein and max out at 50 g, you need another meal
What about the timing of protein intake in relation to exercise/ strength training?
There is debate about this
You will find people and trainers who want to eat protein before a workout
Don did some animal studies on this looking at different timing
He found that that exhaustive exercise is catabolic no matter what
He finds the benefit is after the exercise, not before
When the system is not finely tuned
REDD1 is inhibited
mTOR is ready to go
Peter asks, “Just to be clear, what you’re saying is, look, you can take all those amino acids before but it’s
not going to prevent you from becoming catabolic during exercise?”
Yes
Because exhaustive exercise is a catabolic activity, so you are going to be breaking down
muscle no matter how many amino acids are on board while lifting
It’s more important after the lift, that you have a good meal
Don notes that you’ll find disagreement with that in the literature
But he strongly believes this and his research supports this
Protein needs of children [1:19:45]
Funny story, when Don’s youngest son was 3, for whatever reason he was fixated on protein
Probably because they kept telling him to eat this and that because there was protein in
it, “Hey, eat your salmon. It’s got protein.”
He became the protein police of the preschool
He would walk around and look at kids’ snacks and say, “That doesn’t have protein. That
granola bar does not have protein…. That has protein.”
The people who worked at the preschool asked his wife if she was a nutritionist
So now they joke about how he’s going to be one of these bro protein guys who’s
obsessed with protein
Don doesn’t want everybody to walk away thinking they need to get 50 g of protein into their
kid
Children will be very efficient at maintaining growth with small snacks of eight to 10 grams of protein,
where that will have virtually no impact for an older adult
So a protein bar that had 10 g of protein is a perfectly legitimate snack for a child
Where essentially the only thing it would do is probably increase liver enzymes in a 70
year old
Don doesn’t want all the mothers think they’re doing a bad thing by giving their child a
10 g protein snack
Differences in protein requirements for children and adults and when that protein is
consumed
In the adult, say they eat 100 g of protein in a day but take it in very small meals
15 g trickled in all day long
This will never stimulate muscle protein synthesis
But their liver will be perfectly fine
Your gut, liver, heart, kidneys, will all respond to the net protein per day, no matter
when you ate it
Muscle is different, it is specific
Muscle isn’t triggered unless the diet is exactly right
The muscle senses energy, insulin, and protein before it triggers
And if all of those aren’t balanced it won’t trigger, but your liver will
Peter notes, “Teleologically you might make the case that the liver has more concern for the brain than
the skeletal muscle, and maybe it gets priority over being happy because it has to maintain glucose
homeostasis. And without glucose homeostasis the brain would literally die within 20 minutes.”
Don agrees, “Your liver, your heart, those have to function. In the middle of the night, your liver still has
to be making protein, but your muscle doesn’t.”
While you’re laying there in bed, your muscle is catabolic and it’s supplying amino
acids so all those other organs work
So while Don will argue about muscle-centric health, the reality is, moment to moment, it’s
organ-based
But long-term, your overall health is determined on keeping the muscle healthy because it keeps
everything else healthy
Is the reason that it’s okay for kids to be eating much smaller amounts of protein, is it simply
just the mass?
Peter’s youngest weighs 25 kg
He probably doesn’t need more than 40 g of protein a day
For him to have a 10 g serving, this is 25% of his protein
For Peter 25% of his daily protein is 40 g
Don points out that for children, their protein synthesis is driven by hormones
This is not true for adults
Growth in children is highly efficient, it’s driven by hormones, and children will accommodate protein
in small doses
How important is timing protein intake around training? [1:24:15]
What is the window in time, post workout, in which you want to make sure you’re getting
that first big meal of protein?
Don first did this experiment in rats
Josh Anthony and Tracy Anthony were in his lab just before Layne Norton came in
They were looking at exhaustive exercise in rodents and catabolic state
They wanted to know how the muscle regulated recovery
They were looking at what we called initiation factors (for initiation of protein
synthesis, aka translation)
They discovered a link between leucine and initiation factor eIF4
That is a downstream effect of mTOR
mTOR is the regulator and it stimulates eIF4, S6, and other initiation factors
They found that when you come out of an exhaustive exercise, muscle is catabolic until you
take in enough leucine to reverse it.
They started looking at feeding right after exercise
A lot of people picked up on that‒ Stu Phillips, Doug Paddon-Jones, and others
What are the caveats?
There is a 2 hour window right after exercise where you can see the biggest effect of
feeding, but this is in untrained individuals
If you look longer, you can have a bout of resistance exercise and you’ll detect a difference
You’ll start regulating that REDD1 protein factor
You’ll see an anabolic effect the next day (24 hours, 36 hours later)
The more trained you get, the less you’re going to see a post-exercise effect
Don’s summary:
If you’re beginning training and you’re in the first 4 weeks, post-exercise protein probably
makes sense
If you’re well trained, you’re basically training the same way and you’ve been doing it for 6
months, Don doesn’t see any effect difference between having protein within 2 hours after
exercise versus just having your 3-4 four meals per day
You won’t see any difference in either mass or strength
Peter remembers having this discussion with Layne and being pleasantly surprised to learn‒
once you get to a point where you’re well trained enough, you don’t have to be so maniacal
about meal timing
You can just focus on the big picture, which is: total protein, protein quality, and
spreading it out such that you don’t exceed the metabolizable fraction of it at any one
sitting
Don agrees
How much protein can muscle use at any one sitting?
Don hears trainers take that last statement about metabolizable energy and say “Well, you can’t
use more than 30 grams at a meal. You won’t digest it.”
That’s not true
You’ll digest and absorb 100 grams of protein at a meal. But muscle in particular only has a window of
around 25 to 60 grams (depending on protein quality) that it can use. The liver will use all of it.
We have what is known as first pass metabolism of protein (which confuses the issue even
more)
When you eat a meal of protein, approximately 50% of the protein is degraded to
nitrogen and carbon before it ever gets to the blood
The exception to that are the branch chain amino acids: leucine, isoleucine, valine,
where almost 75 to 80% of those get into the blood
Now we’re back to the teleological argument, “Why did muscle learn to sense that?”
Because that basically shows up in the blood in direct proportion to the meal and the
muscle learned to sense that as a meal quality
This is a signal that a meal has adequate quality for muscle to trigger the very expensive
process of protein synthesis, protein turnover
And until muscle sees that signal, it won’t do it
The role of leucine in fatty acid oxidation by muscle [1:28:15]
The other thing Peter has learned recently that surprised him is the importance of leucine in
fatty acid oxidation by the muscle
One of the pillars of his practice is low-end aerobic training (zone 2)
This is important for mitochondrial efficiency
This is basically pushing your muscles to their maximum point at which you can keep
lactate below 2 mmol
A very fit individual can generate a lot of power while still keeping lactate below 2
mmol
The best in the world can produce more than 4 watts per kilo while still keeping lactate
below 2 mmol, and they’re doing so virtually exclusively with fatty acid
Peter will pair this type of analysis with CPET (cardiopulmonary exercise test) testing, and
will look at fat oxidation rates
Again, you will see the fittest of the fit have insanely high fat oxidation rates, they’re
roughly 1 gram per minute
The point being, a really good muscle doesn’t just rely on glucose
A really good muscle can oxidize fats very effectively
What role does leucine play in that?
That’s a great question, one that Don doesn’t think has been researched enough
Every amino acid has a different side chain, and leucine is one referred to as a branch chain
amino acid
The side chain of leucine is purely carbons, it looks a lot like a fatty acid (see the figure
below)
Figure 11. Leucine and a fatty acid. Image credit: OpenStax Biology 2e
Leucine is one of 2 amino acids that are ketogenic, it’s metabolized as a fatty acid
Leucine will also activate the CPT1 enzyme (carnitine palmitoyltransferase enzyme), which is
the link for bringing fatty acids into the mitochondria for oxidation
So there’s a benefit there
It gets even more complicated, in that when you have higher leucine‒ it begins to inhibit
pyruvate from going into the mitochondria
So when you oxidize a leucine, the nitrogen that comes off of it is put onto pyruvate,
generating alanine, and so the body begins to recycle glucose
It becomes steady state on glucose and emphasizes fat oxidation
If you overload all of that, you can make leucine inhibit carbohydrate oxidation
So if you have huge amounts of carbs coming in, and then you overload the system with
leucine, and you’ll inhibit pyruvate oxidation
So that could look like insulin resistance
But if you look at the physiology of how it’s supposed to work, under conditions where you’d
be burning fat, leucine actually stimulates fat oxidation and spares glucose for the brain and
other tissues
So again, you really have to think about how the experiment’s set up, what’s getting inhibited
and what’s getting pushed?
High protein diets for fat loss: Results from Don’s clinical trials [1:31:30]
Peter thinks of 3 strategies to approach weight loss
1 – Reduce calories, pay attention to the total energy content of food without thinking about
the timing of food or macro distribution of food
2 – Focus on macronutrients, spend less time thinking about the total number of calories and
avoid certain foods
Create a boogeyman in the diet
The restriction of certain things becomes a roundabout way to restrict total energy
3 – Time restricted feeding (intermittent fasting)
How does Don think about manipulating #2, changing macros to achieve energy deficit?
Don agrees, weight management is a calorie issue
It’s not the same for every individual, everybody’s got a little different efficiency
So you can’t be an accountant and expect to just count calories all the time
A bit of history starting in the late ’90s…
Atkins and the keto diet were out there
Barry Sears and the Zone diet
Michael Eades and the Protein Power
Don was looking at all of these things and doing leucine experiments
Don discovered this effect of leucine on muscle protein turnover and some of these metabolic
things with fat metabolism
He basically took the leap of faith and said, “I think the underpinning of all of these diets is really the
protein carb ratio and how can we manipulate that?”
He started thinking about creating a diet from a satiety standpoint
Protein is probably the most satiating
Fat would be next
Carbohydrate the least
They were concerned about big insulin swings
They wanted to balance out our carbs per meal
They know that if people are overweight, they tend to have big post meal
carbohydrate and insulin swings where 2 hours later, they’ll have carbohydrate
lows
He began to think that the first meal after an overnight fast is critical
He asked, “How much protein do you need?”
30, 40 grams of protein to get both satiety, protein synthesis effects
They knew that protein had a higher thermogenic effect (burns more calories) than
either carb or fat and they wanted to front-load that effect
People argue that because of the nitrogen, protein is harder to digest and absorb, but he didn’t
think that was true
They thought the thermogenic effect is stimulating muscle protein synthesis, that is a
massive ATP expenditure
They wanted to maximize that at every meal
For the 1st meal they wanted 40 grams of protein, and they wanted to have a carb level that would not
overstimulate insulin
So they kept the carbohydrates under 30 grams
This created a carbohydrate threshold concept
They could use fat to round out the calories
Human clinical trials
They increased protein intake to about 1.6 g/kg and ran a study comparing it to the food
guide pyramid recommendation of 0.8 g/kg
They did 3 studies
1 – A total feeding study where they fed everyone in the lab
2 arms of the study were (1) high carb/ low protein and (2) low carb/ higher
protein
Published in 2 papers, one about body composition and lipid profiles and the
second about glucose and insulin homeostasis
2 – A study with diet and exercise for 4 months
They provided participants meals for the 1st 2 weeks
A 2×2 design of diet treatment and resistance exercise treatment
3 – A multi-centered study with 120 subjects for 16 months
Free living studies where participants provided their own food following diets
and manuals provided
Diet with a generic recommendation for exercise comparing high
carbohydrate:protein ratio diet to a low carbohydrate:protein ratio diet
Results from study #1
With exactly the same calorie intake, the people on the higher protein, low carb diet
lost more total weight, more total fat and less lean, and that stabilized their insulin and
glycemic regulations and lowered their triglycerides across the board
What was the difference in weight and fat mass? Was it all explained by the thermodynamics of the difference in
protein?
It was close
They found that the people on the higher protein diet were getting a benefit of around 170
calories a day eating the same calories
So that could be about the thermodynamic effect
Both groups lost weight, they were both on weight loss diets
But the protein people lost lost around 8 lbs. more and something like 6.5 lbs. of it was fat
Did the people on the high protein diet complain less of hunger?
They did a satiety check using an analog scale to asked them to rate how they felt
One of the things that the dieticians who were running the study always came back is they
said that the protein people were never talking about food and snacks, but the people on the
high carb diet were always talking about being hungry and snacking
“There’s definitely a different satiety and compliance issue to it”‒ Don Layman
Did the results of all 3 studies point in the same direction?
Yes, greater weight loss was observed in people on a higher protein diet
Peter’s takeaway:
Stop thinking about protein as a percent of total calories, protein should always be absolute
Then as you reduce calories, protein should increase the total fraction of calories
This is going to preserve lean tissue better, maintain satiety better, and plus there’s potentially
this bonus of the thermogenic effect of protein
Don adds that this definitely partitions the weight loss toward fat, protects muscle/ lean
tissue, and definitely has higher satiety
Weight loss in people over 60
For a long time there was a lot of debate over whether people over 60 should ever practice
weight loss because they would lose too much lean mass (muscle) and they can’t gain it back
Doug Paddon Jones had the theory that sarcopenic aging isn’t a gradual decline
Instead it’s a series of acute effects that you injure yourself (you’re in bed; you have a
surgery, whatever), you acutely lose lean mass, and you can never gain it back
“We want weight loss, but we don’t want people to lose any lean mass, especially if they’re adults.”‒ Don
Layman
If you are a 20-year old, it probably doesn’t matter so much
But if you’re older, if you’re beyond 40, it does matter
Peter reacts, “It’s a scary thought, Don, if you think about it, right? 40 is not that old.”
Peter just had shoulder surgery 5 months ago and he still has not gained back all of the muscle
mass
Gaining it back has been difficult in comparison to how acutely he lost it
In 3 weeks, he was 10 lbs lighter
It’s not just from the shoulder, it’s all the things you can’t do when you don’t have an
arm
You can’t squat, you can’t deadlift, etc.
Some of that 10 lbs. was water weight, but 7 lbs. was lean tissue that he lost in 3 weeks
There is a bed rest study by Doug Paddon Jones (who unfortunately passed away this last
year) looking at older adults versus younger adults
In the same period of time, an older adult in bedrest will lose 4x as much muscle as a
younger adult
It’s frightening how fast you can lose it
If you’re diligent and do weight training, you can begin to gain it back
But it’s hard to get back to where you were
How does leucine come into play?
It’s not as important for a 20 year old as it is for a 60
Don thinks it’s a little like bone health‒ once you’re 40, you’re sort of on the back end of that,
and you need to be much more careful
Don did a study with Doug Paddon Jones where they took 90 grams of protein and looked at
it distributed as 3 meals per day, 30, 30, 30 versus 10 20 60.
They found that with the same amount of protein, the same overall diet, you would have
higher net protein synthesis with the distribution to breakfast
This was a study of 37 year olds (mean age)
So they think that by mid thirties, you can detect the distribution effects
Peter asks, “Just to be clear, Don, do you think that the reason 30, 30, 30 was better than 10, 20, 60, was
because you started the day at 30, or because you had 3 meals where you cleared the hepatic threshold?”
That’s a great question, Don thinks they would have been better off studying a protein split of
40, 10, 40
“I think the first and last meals are the key”‒ Don Layman
They’ve done a number of studies in animals
Other people (Mike Rennie and Phil Atherton) have done it in humans
When you trigger mTOR at that first meal (we know that it’s still stimulated five hours
later), why do you need leucine for mTOR at lunch if it’s still simulated?
You don’t
Nobody has actually studied that at this point
The key here is, “Now you’re talking total protein per day, not a leucine effect. It’s not a leucine- mTOR
effect, there’s not this threshold to it.”
It’s total substrate
Layne needs 250 grams of protein per day, he’d be better off putting that in 4-5 meals than
putting it in 2
People need to understand that distributing across all the meals is not an mTOR effect
Distributing it this way is great for weight loss and appetite
Influence of industry funding on nutrition studies [1:43:45]
So much of this research that Don has done has been funded by industry
A lot of people are going to say, well, we’re going to discount everything
Who has funded his work over the last 4 decades?
In the early 80’s Don had the concept that leucine was going to be key to protein synthesis in
muscle
They ran studies and realized it had initiation effect
They started looking for the initiation factors and found eIF4
They submitted proposals to the NIH for 10 years and were continuously turned down
The NIH said, “We only study disease and we don’t know of any deficiencies of protein, so it’s not
a priority to us”
Don was left with what turned out to be a revolutionary idea of reinventing protein, that
NIH wouldn’t fund
He finally went to Kraft Foods, the National Cattlemen’s Beef Association, the National
Dairy Association, American Egg Board, and some of the other groups who were inherently
interested in protein
They got some money from the USBA
Don was at a land grant university and those were the funding sources that unlocked all of
this knowledge about protein for adults, leucine, mTOR, muscle-centric health
All of that was unlocked simply because he could get funding from Kraft and Beef
Is Don biased? Everybody who eats is biased in some way
If you look at research, he never believes research until he sees it from 3 more labs
So he doesn’t mind if people look at his research and say, “I don’t believe it,” but his research has
been out there, very clear theories for 20 years now
And every test makes it stronger
Everybody who’s ever run the study after me shows the exactly same thing
The fact that Kraft or Beef funded, it’s irrelevant
Don is semi-retired now, retired from the grant cycle
Does Don see any evidence that the NIH has taken a broader purview of health?
Don thinks they have
Chris Lynch, is the director of nutrition at NIH now
That position didn’t exist back in the late 80s to early 90s
It sits across multiple institutes, maybe NIDDK and the Cancer Institute
There was a general philosophy (and still is) at the NIH, that they do not fund applied food
research
They believe industry should fund it
So that becomes a catch 22
If you’re going to study the difference between whey and soy protein, unless you can say that’s
going to cure heart disease, they’re not going to fund it
So then you have to go to the dairy council (or whatever) and say, I want to do this study
“The alternative is we put our head in the sand, and we don’t do the research”‒ Don Layman
When Don looks at people in nutrition right now, he literally doesn’t know anybody in
nutrition who doesn’t get industry funding
It’s just simply how you have to get funded
One of the things he would also point out in this whole issue of bias, it’s important to
recognize that the animal commodities are all under the USDA supervision and they have
checkoff boards
So that means everything they say in advertising has to be screened
Where as the grain industry has big companies like Kelloggs and Pillsbury and Coke and
Pepsi, they can literally go out and say anything they want
And so you’ll see a product out there that pretends to be an egg and they’ll claim that they’re
better than eggs, but egg can’t come back and refute it
So you’ve got two different playing fields, one that’s highly restricted and supervised and the
other, which is fair game, first amendment, I can say anything I want
Don’s thoughts on plant-based and synthetic “meats” [1:48:45]
Thoughts on the nutritional/ amino acid composition of plant-based meats
There are a whole host of companies trying to make synthetic meat
From the little Peter has read about it, he has the impression that it will not be technically
feasible from the standpoint of energetics, cost mass balance, sanitation, and GMP
Don thinks as the world continues to expand in population, we’re going to need additional
protein sources
We may be near our capacity for animal-based protein
He doesn’t think we can double it again
He agrees with Peter’s comments about synthetic proteins, “I don’t think that will ever be
economically or environmentally feasible”
Popular versions of plant-based Beyond Burgers, etc look like a flash in the pan
Burger King’s Impossible Whopper had good sales for a few months, but if you track it, it was
all people who don’t normally go to Burger King
Once people tried it, the never came back
The stock has fallen through the bottom now, nobody’s using it
Beyond Burger is basically a pea protein produced in Canada
It’s then shipped to China, processed, and shipped back to the US
We know transportation is a #1 cause of greenhouse gas
Now it’s been shipped all over and comes back to the US with around 25 ingredients,
probably 5-6 are not FDA approved
They have multiple products containing multiple synthetic components that have never
really been studied and are not FDA approved
They’re basically relying on safety without ever proving it
Don thinks plant-based proteins have been around for a long time
Don’s takeaway: “I think that plant-based proteins have been around a long time. I think trying to pretend
that it’s meat, calling soy drink milk or almond drink milk. I think those are travesties. I think those are standards
of identity. Almond milk has, what, one gram protein per eight ounces where cows milk has eight? Calling that
milk is pure deception.”
He’s not against using them, but he thinks the consumer should be aware
For example, if you look at any wheat cereal it has 4 grams of protein per serving
He always said that’s probably only 2 grams
On the label it says, mix it with ¾ of a cup of milk, and now we have 10 grams of
protein
If you look at the lysine balance of that, it’s exactly balanced
But if you go to soy milk, this has only 6 grams of protein per 8-ounce coup instead of 8
And it’s deficient in lysine
So it takes almost a quart of soy milk to balance that cereal
If you’re a mother feeding this to your child and thinking, well, I’m doing a plant-based thing
and I’m feeding them a totally deficient diet with 6 ounces of soy milk for breakfast
How many mothers know that?
Those are the kinds of things that we think need to come out about protein quality
We want a system where we can show people an additive value and that at the end of it when
they put that meal together
There’s a company called WISEcode that Don is working with
They think that they can use QR codes and your phone to simply add up the quality protein
content and can tell what your total meal looks like
Getting enough protein and enough quality protein in the diet is hard
Peter is not sure he hits the total grams of protein he wants each day
And there’s no attention to how much methionine, leucine, or lysine he’s getting
Don replies, “If you’ve got 125 grams of protein in your diet per day, chances are you’ll hit those numbers.
Where leucine is a meal to meal number, lysine is a daily number (it doesn’t matter meal to meal, it’s a
total).”
Peter notes for many of his female patients, it’s hard to get them up to 120 grams of protein
per day
Don agrees, with his studies he struggles to keep adult females at 100 grams of protein per day
Then quality becomes an issue
This is Don’s concern with the plant-based movement‒ do people have the resources to make it
healthy?
You can, but you need a lot of knowledge and food skills
You’re going to have to eat synthetic products because you can’t get it from eating
lentils and rice
You just can’t eat enough of them
So you’re going to have to have shakes or supplements to get to that level
The track record says vegetarians end up somewhere in the 60s for their protein per day, and
quality does make a difference at that level
Problems with epidemiological studies of dietary protein [1:56:30]
What does high protein mean?
When you look at the epidemiology, Don thinks the science is bad
The definition of high protein is about 1.2 g/kg and low protein is actually below 0.8
Many will express it as % of calories and they’ll say less than 10%
When you look at the epidemiology, you need to realize they’re talking about very narrow
ranges of protein intake and it really isn’t the protein that’s making a difference, it’s the
calories and the other things that are going with it
Don’s experience as director of research for the American Egg Board
For 4 years Don was director of research for the American Egg Board
He funded all of the research that basically got the cholesterol direction eliminated from our
guidelines
One of the things funded was a lot of research suggesting that eggs had a high correlation
with obesity and diabetes and heart disease
They funded some research with Theresa Nicklas and Vic Fulgoni who were experts in the
NHANES data, and they looked at the epidemiology
They looked at the difference between the first quartile and the last quartile for egg
consumption
It was 3-3.5
So they were basically saying that a half an egg per week was the difference in causing obesity, heart
disease and diabetes
And so what they did was they went into the NHANES data and they factored out all of the
eggs that were eaten at fast food versus the eggs that were just eaten at home in a “good
nutrition setting”, and what they found is in every case, eggs now became a positive
They reduced obesity
So basically it’s not the egg, it’s the egg in the company it keeps
You can make anything a bad diet
Peter adds, “Anybody who’s tried to actually consume high protein, realizes it ain’t high protein, it’s high
calorie that’s the problem”
The protein is along for the ride
Because 1.2 g/kg is actually kind of low protein in the context of a high calorie diet
Don notes that the surveys for protein used in epidemiology are pretty good
People can tell you how many eggs they ate yesterday, or ounces of milk, or grams of
meat
Because we sell those by ounces and weight
In contrast, most people misreport the number of carbs they ate by 200 grams
“The problem with epidemiology is that the errors are not homogeneous”‒ Don Layman
§
SELECTED LINKS / RELATED MATERIAL
Episode of The Drive with Layne Norton: #205 – Energy balance, nutrition, & building muscle |
Layne Norton, Ph.D. (Pt.2) | Host Peter Attia, The Peter Attia Drive Podcast (May 2, 2022) | [6:15]
Episode of The Drive with Gerald (Jerry) Shulman: #140 – Gerald Shulman, M.D., Ph.D.: A
masterclass on insulin resistance—molecular mechanisms and clinical implications | Host Peter
Attia, The Peter Attia Drive Podcast (December 7, 2020) | [9:45]
Bob Wolfe’s experiment with stable isotopes examining fatty acid oxidation: Glucose and
insulin-induced inhibition of fatty acid oxidation: the glucose-fatty acid cycle reversed | American
Journal of Physiology: Endocrinology and Metabolism (LS Sidossis and RR Wolfe 1996) | [12:15]
Hellerstein paper showing low level of de novo lipogenesis after carbohydrate feeding: Effects
of a low-fat, high-carbohydrate diet on VLDL-triglyceride assembly, production, and clearance | The
Journal of Clinical Investigation (EJ Parks et al. 1999) | [14:00]
Hirsch study of high carbohydrate diet showed increased fatty acid synthesis: Human fatty
acid synthesis is stimulated by a eucaloric low fat, high carbohydrate diet | The Journal of Clinical
Investigation (LC Hudgins et al. 1996) | [15:45]
Volek study of high carbohydrate diet showed increased fatty acid synthesis: Effects of StepWise Increases in Dietary Carbohydrate on Circulating Saturated Fatty Acids and Palmitoleic Acid
in Adults with Metabolic Syndrome | PLoS One (BM Volk et al. 2014) | [16:00]
Don finds reducing the number of meals per day is thermogenically advantageous (in rats):
Effects of prolonged meal-feeding on the body composition of adult rats | Nutrition Research (BJ
Bittman et al. 1984) | [17:45]
Summary of Ancel Key’s seven countries study: Seven Countries Study | University of
Minnesota: Heart Attack Prevention: A History of Cardiovascular Disease Epidemiology | [18:30]
Minnesota Coronary Experiment republished by Chris Ramsden: Re-evaluation of the
traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment
(1968-73) | BMJ (CE Ramsden et al. 2016) | [20:45]
Episode of The Drive with David Sabatini: #09 – David Sabatini, M.D., Ph.D.: rapamycin and the
discovery of mTOR — the nexus of aging and longevity? | Host Peter Attia, The Peter Attia Drive
Podcast (August 13, 2018) | [50:00]
Episode of The Drive where Matt Kaeberlein discusses mTOR: #222 ‒ How nutrition impacts
longevity | Matt Kaeberlein, Ph.D. | Host Peter Attia, The Peter Attia Drive Podcast (September 12,
2022) | [50:00]
Leucine sensor on mTOR: Sestrin2 is a leucine sensor for the mTORC1 pathway | Science (RL
Wolfson et al 2016) | [50:00]
Link between amount of DNA and muscle development in rat weanlings: Cellular growth of
skeletal muscle in weanling rats during dietary restrictions | Growth (SR Glore and DK Layman 1983)
| [1:10:45]
Link between leucine and initiation factor eIF4: Orally administered leucine stimulates protein
synthesis in skeletal muscle of postabsorptive rats in association with increased eIF4F formation |
Journal of Nutrition (JC Anthony et al. 2000) | [1:25:00]
Feeding study comparing high carb/ low protein and low carb/ higher protein diets:
A Reduced Ratio of Dietary Carbohydrate to Protein Improves Body Composition and Blood
Lipid Profiles during Weight Loss in Adult Women | The Journal of Nutrition (DK Layman et al.
2003) | [1:35:15]
Increased Dietary Protein Modifies Glucose and Insulin Homeostasis in Adult Women during
Weight Loss | The Journal of Nutrition (DK Layman et al. 2003) | [1:35:15]
2×2 study evaluating dietary protein and exercise on weight loss: Dietary protein and exercise
have additive effects on body composition during weight loss in adult women | The Journal of
Nutrition (DK Layman et al. 2005) | [1:35:15]
Multi-center study of low carbohydrate: protein ratio diet to high carbohydrate:protein diet
with exercise: A moderate-protein diet produces sustained weight loss and long-term changes in
body composition and blood lipids in obese adults | The Journal of Nutrition (DK Layman et al. 2009) |
[1:35:15]
Bed rest study by Doug Paddon-Jones: Protecting muscle mass and function in older adults
during bed rest | Current Opinion in Clinical Nutrition and Metabolic Care (KL English and D PaddonJones 2010) | [1:40:45]
Study of protein distribution over 3 meals shows the importance of dietary protein at
breakfast for muscle synthesis: Dietary Protein Distribution Positively Influences 24-h Muscle
Protein Synthesis in Healthy Adults | The Journal of Nutrition (MM Mamerow et al. 2014) | [1:41:30]
Dietary recommendations for protein and leucine intake (review): Optimizing Adult Protein
Intake During Catabolic Health Conditions | Advances in Nutrition (SM Phillips, D Paddon-Jones,
and DK Layman 2020)
§
PEOPLE MENTIONED
Layne Norton (professional bodybuilder and physique coach) [2:45, 6:15, 1:24:30, 1:43:15, 1:45:30]
Ancel Keys (American physiologist who promoted replacing saturated fat with unsaturated
fat to reduce cardiovascular disease) [6:00, 18:30]
Henry Blackburn (Professor Emeritus, Division of Epidemiology and Community Health at
the University of Minnesota School of Public Health) [6:00, 20:00]
Ivan Frantz (Expert in nutrition and cardiovascular risk, led the Minnesota Coronary
Experiment) [6:15, 20:00, 24:15]
Gabrielle Lyon (doctor specializing in muscle-centric medicine) [7:31]
Gerald (Jerry) Shulman (George R. Cowgill Professor of Medicine (Endocrinology) and
Professor of Cellular And Molecular Physiology at Yale University and Co-Director of the
Yale Diabetes Research Center) [9:45]
Robert (Bob) Wolfe (Professor at University of Arkansas for Medical Sciences and Director of
the Center for Translational Research in Aging and Longevity at the Reynolds Institute on
Aging) [12:00]
Marc Hellerstein (Professor of Metabolic Nutrition at UC Berkeley) [14:00]
Jules Hirsch (physician-scientist, obesity expert) [16:00]
Jeff Volek (Chief Science Officer and Co-Founder of Verta Health) [16:00]
Gil Leveille (Biochemist and expert in metabolism) [17:00]
Fred Kummerow (biochemist and lipid expert who pioneered the connection between trans
fats and heart disease) [20:00]
Arlan Richardson (Don’s Master’s advisor, now Professor of Geriatric Medicine at the
University of Oklahoma) [26:30]
David Sabatini (American scientist, expert in growth, metabolite profiling, and aging) [50:00]
Matt Kaeberlein (Professor at the University of Washington, expert in aging) [50:00]
John Waterlow (British physiologist, expert in childhood malnutrition) [1:07:00]
Joe Millward (British physiologist, expert in nutrition and metabolism) [1:07:00]
Peter Garlick (former Professor at the University of Illinois, Urbana-Champaign, expert in
metabolism) [1:07:00]
Vernon Young (National Academy of Sciences member, expert in protein requirements)
[1:07:00]
Joshua Anthony (Did his Master’s with Don, nutrition expert, Founder and CEO at Nlumn
LLC) [1:24:30]
Tracy Anthony (Did her Master’s and Doctorate with Don, Professor of Nutritional Sciences
at Rutgers University) [1:24:30]
Stuart (Stu) Phillips (Professor of Kinesiology at McMaster University) [1:25:30]
Douglas Paddon-Jones (Expert in nutrition and aging, was a professor at the University of
Texas Medical Branch) [1:25:30]
Robert Atkins (Cardiologist and creator of the Atkins diet) [1:32:45]
Barry Sears (Biochemist and creator of the Zone diet) [1:32:45]
Michael Eades (Physician and creator of the diet Protein Power) [1:32:45]
Christopher Lynch (Acting Director of the NIH Office of Nutrition Research) [1:46:30]
Theresa Nicklas (Professor of Pediatrics-Nutrition at Baylor College of Medicine, expert in
children’s nutrition) [1:57:30];
Victor Fulgoni (Vice Chairman of Nutrition Impact at Battle Creek, MI) [1:57:30]
§
DON LAYMAN, PH.D.
Donald Layman is a Professor Emeritus at the
University of Illinois Urbana-Champaign College of
Agricultural, Consumer and Environmental Sciences in
the department of Food Science & Human Nutrition.
Don earned his B.S. in Chemistry and M.S. in
Biochemistry at Illinois State University and his Ph.D.
in Human Nutrition and Biochemistry at the
University of Minnesota, St. Paul. His research focuses
on understanding the protein and amino acid
requirements and interrelationship between dietary protein and carbohydrates needed for
adult health. In particular, his research seeks to understand the impact of diet and exercise on
obesity, type 2 diabetes, and metabolic syndrome in adults. His work has helped to define the
role of branched chain amino acids (BCAA) in skeletal muscle metabolism. BCAA provide an
important energy source for muscle during exercise and also serve as a critical regulator of
muscle protein synthesis during recovery. During exercise, oxidation of BCAA increases,
resulting in production of the amino acid alanine and a rapid decline in plasma levels of BCAA.
Amino acid supplements prevent this decline in plasma amino acids, enhance recovery of
muscle protein synthesis and interact with insulin to help stabilize blood glucose. His research
continues to define mechanisms for control of muscle protein synthesis and differences in
dietary protein needs for men versus women and for adults with sedentary versus active
lifestyles. Don currently consults for many food industry companies including Kraft, Nestle,
Hershey, the Dairy Council, the Egg Board, and the Beef Board. [University of Illinois
Urbana-Champaign]
Twitter: @donlayman
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