The ultimate protein episode: Nutrition scientist Don Layman, Ph.D. | mbg Podcast

Only 7% of U.S. corn is fed to cattle; 40% is used for ethanol fuel production and 15% for high-fructose corn syrup, making these non-nutritional uses significant drivers of corn production

“about seven percent of the corn grown in the United States goes to cattle and 40 percent goes to ethanol for cars and another 15 percent for high fructose corn syrup”

The prevailing dietary guidelines have created a 40-year period (1980-2020) of anti-cholesterol, low-fat, high-carbohydrate recommendations that promoted snack cakes, Crisco, margarine, and other processed foods later proven unhealthful, representing a massive failure of nutrition policy

“we had basically a 40-year period where we got snack well cookies and crisco margarines and all kinds of junk that were all based on cholesterol was bad for you we know that's not true”

The recent shift toward reconsidering cholesterol and saturated fat (away from the 1970s-2000s anti-fat consensus) has been driven by research from scientists like Ron Krauss and others, challenging the decades-long narrative that blamed saturated fat for heart disease.

“what Ron Krauss and Jeff folic and others have shown is that saturated fats really aren't bad unless you're eating too many calories”

If total daily protein intake is higher than 200 grams per day, excess protein above the 160-gram muscle-building target will increase liver, kidney, and GI tract size rather than increase muscle mass

“so if I have uh 200 grams if I if my muscle Target as I mentioned earlier is like 160 grams per day uh if I go to 200 I probably won't have any bigger muscles but if I go to 200 I will have a bigger liver kidney and GI tract so your lean body mass might get higher but it really didn't help your muscles”

Grass-fed cattle produce more methane than grain-fed cattle due to bacterial fermentation of grass (not the cow belching), but grain-fed cattle finish faster, requiring less time to reach market

“when they're eating the grass and forage they produce a lot more methionine and CO2... it's not actually the cow it's the bacteria that are fermenting the grasses and so when you feed them corn uh to finish instead of grasses it actually reduces the uh uh the methane emission about four-fold”

High-fiber whole foods (vegetables, berries, legumes) should be preferred over low-fiber refined versions; bananas and fruit juices are exceptions to the 'eat fruit' rule due to high sugar-to-nutrient ratios.

“then you make your uh next choice about vegetables and berries high fiber fruits and vegetables not bananas uh you know not orange juice but natural fruits high fiber forms”

Hypertrophy (muscle growth) is 75% resistance training and 25% protein intake; protein cannot substitute for inadequate training, and excessive protein intake beyond meeting the threshold cannot compensate for poor training

“hypertrophy is 75 percent resistance training and 25 percent protein intake you know it's it's heavily weighted to the training if you if you want to gain muscle mass you're going to do that in the gym you can't eat you can't eat your way into more protein”

The post-workout anabolic window is primarily relevant for untrained individuals recovering from their first catabolic workout; for trained athletes eating regular meals (4+ daily), the timing of individual meals relative to workout is much less important than was previously believed

“the issue is all of that relates more to untrained individuals than it does to trained if you just start training from zero you're going to go into a fairly catabolic period during that training and so the quicker you can recover from it the more likely you can get hypertrophy... if you're well trained it probably doesn't make any difference if you're an athlete and you're eating four times a day whenever you have your exercise the next meal is close enough”

Plant-based eaters should consider supplementing with isolated plant proteins (soy, pea) or plant-based supplements to achieve adequate protein intake without excessive carbohydrate consumption, and should engage in resistance exercise to improve protein efficiency

“plant-based people need to think about some of the plant you know the isolated proteins whether it's soy or Pea or some of those kinds of things they they almost need to think about supplements and to our earlier point they definitely need to be involved with resistance exercise”

Aerobic exercise burns approximately 10 grams of protein per hour; athletes exercising 3 hours per day need an additional 30 grams of protein beyond baseline requirements

“we know that uh aerobic exercise burns about 10 grams of protein per hour so if you're working out three hours per day that's adds 30 grams of protein on top of whatever you thought your need was”

For growing children, absolute protein distribution across meals is less important than total daily intake; children do not require the same meal-by-meal leucine threshold as adults because they are still hormonally driven

“when you're a child uh you're basically dominated by hormones you're going to grow... individuals under 25 don't seem to be very sensitive to meal distribution they just it's a quantity per day”

The food guide pyramid (high-carb, low-protein diet) actually minimized the benefits of resistance exercise, showing that this dietary recommendation was counterproductive for people trying to build or maintain muscle

“what we showed was that the food guide pyramid the high carb low protein diet actually minimize the benefit of doing resistance exercise”

Saturated fat is not harmful to health unless consumed in excess calories; the body naturally produces palmitate (a saturated fat) through evolution, and if saturated fat were toxic, humans would not have survived millions of years of evolution

“we know that saturated fat really isn't bad unless you're eating too many calories... the body makes fats the only body The only fat the body actually can make is palmitate which is a saturated fat and considered the most unhealthy but after a million years of evolution the body only makes that one so if it's really toxic we should all be dead the issue is amounts”

Muscle comprises close to 50% of body weight and is the primary site for most glucose and fat metabolism, making it critical for functional mobility, insulin sensitivity, and the ability to metabolize carbohydrates and fats

“muscle makes up close to 50 percent of your body and it's a primary site for most of your glucose and fat metabolism so obviously it provides for functional mobility... it also is a major issue for things like insulin sensitivity how we use glucose it determines how many carbs you can actually use... the primary fuel of muscle is fats”

Muscle undergoes cycles of anabolic and catabolic states; during the 12-hour overnight fast, muscle is continuously catabolic (breaking down) because the liver requires amino acids to maintain protein synthesis and regulate the body throughout the night, with no stored amino acid pool available

“the body is constantly going through cycles that are anabolic and catabolic particularly muscle... the liver in the middle of the night the liver is making protein to regulate the body and if it stops making protein you die so so where does the liver get amino acids for protein in the middle of the night well it gets it from muscle the body has no storage for amino acids so it gets it from muscle so that means muscle during the night time is catabolic it's breaking down”

Research findings should not be believed based on a single study; confidence in a finding should only increase after it has been replicated independently in 2-3 additional laboratories

“my comment to people is if you see something in a headline about nutrition don't believe it uh when you see it repeated in two to three more independent Laboratories start believing it”

Wheat cereal with 4 grams of protein supplemented with 6 ounces of milk creates a complementary protein because wheat lacks lysine (an essential amino acid) and milk is rich in lysine, together providing all essential amino acids

“the wheat cereal is always deficient in amino acid called lysine and the milk is very rich in lysine so that now makes what we call a complementary protein so six ounces of milk with that cereal”

Bacteria on plant roots absorb nitrogen from soil and convert it to organic amines and amino acids; plants make amino acids for themselves (roots, leaves, stems, flowers) rather than for human consumption

“the bacteria on the roots of plants will absorb nitrogen from the soil that's why you fertilize your plants nitrogen from the soil and they make what are called organic amines and those amines then in the plant can be made into amino acids and that's cool plants make amino acids for us the problem is they don't actually make it for us they make it for themselves”

The grandmother's advice to 'eat a variety of unprocessed foods and eat your vegetables' from 50 years ago remains sound nutritional guidance

“what my grandmother said 50 years ago about eating a variety of unprocessed foods and eat your vegetables is is great advice”

Not all essential amino acids are equally essential; histidine has never been shown to be essential in adults despite being classified as essential, because it oxidizes so slowly in the body that depletion is effectively impossible, whereas leucine is rapidly oxidized and creates acute signaling

“all of the essentials are not equally essential which is kind of interesting um for example uh histidine is one of the nine essential it has never been shown to be essential for an adult... we think it's because the way the body breaks it down the way it oxidizes histidine is so slow it takes forever to deplete the body of it... so it's essential but it's not equally essential to leucine which is a critical signal and very rapidly ox oxidized”

The average American consumes approximately 90 grams of protein per day, with 60-65% of that protein consumed at dinner (approximately 10g breakfast, 20g lunch, 60g dinner)

“the average Americans eating around 90 grams per day males females a little closer to 70. but around 90 grams per day but they're eating 60 percent of it or more at dinner 65. so they're eating approximately 10 20 and 60”

The number one source of saturated fat in the modern American diet is cheese, not meat; the second is hydrogenated oils from frying and commercial food preparation

“the number one source of saturated fat now is cheese uh number two I believe is hydrogenated oils frying oils”

One in four people over age 65 will fall; if someone falls once, their chance of falling again doubles; if they break their hip, they have a 30-40% chance of dying within a year, making hip fractures (300,000 annually in the US) nearly as common as heart disease cases

“one out of four people over the age of 65 will fall if you fall once the chances of Falling Again double and if you fall and break your hip you have a 30 to 40 percent chance of dying within a year... there's 300 000 hip fractures in United States annually... the people who have actual heart disease is like 380 000”

70% of American calories currently come from plant-based sources, but 55% of plant-based calories come from added sugars, oils, and hydrogenated fats, and another 35% from refined grains, meaning over 80% of plant-based calories are of poor nutritional quality

“we get 70 percent of our calories now from plant-based foods and it's an awful diet you know 55 of those calories come from added sugars oils and hydrogenated fats and another 35 Come From A fine grain and so over 80 percent of our plant-based calories are pure crap”

Beef consumption in the U.S. has declined 40% from 1975 to present, yet heart disease, cancer, obesity, and diabetes have increased; therefore epidemiological claims blaming beef for modern disease are contradicted by actual consumption trends

“beef consumption has gone down 4 40 percent 40 percent draw and yet heart disease really hasn't changed cancer really hasn't changed obesity and diabetes have skyrocketed so blaming using the epidemiology from 30 years ago to blame beef it just doesn't stand up”

Intermittent fasting is only beneficial for calorie control in those with weight management issues; if weight is not a problem, there is no longevity benefit to intermittent fasting independent of calorie restriction

“now you're have two different goals in mind the reason for intermittent fasting is to control calories so presumably people who are doing it or are struggling with weight I mean to me that's the only real real good reason to do that so you don't think there are longevity benefits to be only if you're arguing calorie restriction”

Bananas contain approximately 35 grams of pure sugar with essentially no other nutrients unless the peel is eaten, and are composed primarily of fructose

“bananas are 35 grams of pure sugar with essentially no other nutrients unless you eat the peel... it's basically all fructose”

Media headlines about nutrition studies are systematically sensationalized; editors' involvement in reporting makes such reports unreliable, and the original peer-reviewed research should be consulted instead

“I never pay attention to things in the news just because I know they're they're sensationalized if it goes through an editor chances are it's not true”

Creatine supplementation has strong empirical support for increasing muscle mass and strength, though the mechanism is unknown; it is not a protein or amino acid

“creatine is a different kind of supplement um in fact we don't even really know the mechanism of that but it's not a protein or amino acid it's it's a model for muscle for muscle I think I think goal is gaining muscle it clearly it has very beneficial effects on both muscle mass and strength so that's a supplement that has great science behind it”

Time-restricted feeding (eating within a specific window but not true fasting beyond 24 hours) is acceptable and can be a useful tool for balancing meal timing to calorie needs without causing the muscle loss problems of extended fasting

“time restricted feeding I don't have a problem with that uh I I frequently don't have my first meal till 10 30 or 11 and I frequently have very little and I quote Lunch Period and then I'll have a dinner so I'm 70 three uh my calorie needs are down”

All animal proteins have higher leucine content than all plant proteins; vegetarians therefore always need more total protein and more total calories to achieve equivalent muscle protein synthesis effects

“all animal proteins have higher leucine than all at than all plant proteins so again the the thing I always you know talk with vegetarians is that it's perfectly fine but you have to realize you will always need more total protein and that means more total calories”

For most healthy adults, yoga and pilates can be sufficient resistance/stretch stimuli for muscle maintenance, though dedicated gym training is necessary to actually build muscle strength and tone

“that might be yoga and pilates it's about stretch it's not about how many barbells you lift uh it's about stretch but if you want to build your strength maybe build some tone maybe build some muscle you've got to get to the gym”

Hydrogenated oils and trans fats are genuinely problematic for health; processed foods labeled 'trans fat free' may still contain trans fats because labeling requires only less than 0.5 grams per serving, allowing manufacturers to manipulate serving sizes to avoid disclosure

“you'll see a lot of products that say that they're trans fat free well as long as the label has less than 0.5 grams per serving they can say they're trans fats free so they're not really trans fat free they've just changed their serving size”

Almond milk contains essentially no protein (approximately 1 gram per 8 ounces), requiring roughly half a gallon to balance nutritional needs compared to 6 ounces of cow's milk

“if you look at almond milk there's essentially no protein in it at all it's like one gram per per eight ounces so you'd have to have something like a half a gallon to balance it out for the child”

Protein is an emotionally charged topic in nutrition because multiple stakeholder groups have financial interests in promoting low-protein narratives: vegans/vegetarians oppose animal protein use, the food industry profits from selling processed grains and low-margin fresh foods, and pharmaceutical companies profit from statin sales by perpetuating anti-animal/cholesterol theory

“there are multiple reasons but um you know first and foremost there's a variety of people who think you just shouldn't use animals so there's an anti-animal use issue... the food industry makes money off of selling things in bags and boxes highly processed grains... and then the third one would be big Pharma uh as long as we have an anti-animal cholesterol saturated fat Theory we can sell drugs statins 90 million Statin prescription is a year in the U.S”

Many snacks marketed for children (breakfast bars, etc.) contain only 2 grams of protein in 200 calories, making them poor nutrition choices; better snacks should contain 10-12 grams of protein

“the snacks that are available tend to be very high sugar high carb high fat with low protein you know breakfast bars and things like that have two grams of of protein in in 200 calories so you know those aren't good choices we would like them to have you know 10 12 grams of of pro protein”

The term 'plant-based' has been co-opted by the processed food industry to describe foods like Oreos and breaded products, when traditionally 'plant-based' meant whole fruits, vegetables, and whole foods purchased from the perimeter of grocery stores

“I think that's an important distinction I think the word the term plant-based has totally been hijacked by by big food uh before we get to fake meat which we will get to you know Oreos are plant-based... everything is plant-based”

The "follow the money" critique of nutrition science is overly simplistic; all researchers have dietary biases (they believe their own diet is healthy) and funding must come from somewhere; commodity-funded research is often more trustworthy than commercial-funded research due to regulatory oversight, but the distinction between funding sources and actual research integrity is more nuanced than simple accusations of bias.

“people say well you're biased I mean let's let's be honest here I mean we all eat uh every researcher eats and I don't know of any researchers says wow I have a really crappy diet and I'm going to study that you know that's sort of you know we all believe that our diet's healthy so we inherently start with a bias on that note”

For practical purposes and to simplify communication with the general public, protein intake should be expressed as an absolute daily amount (100+ grams for healthy adults, 120 grams as the target, 160-180 grams for athletes over 200 pounds) rather than as grams per kilogram or per pound of body weight, because absolute numbers are more actionable and easier for people to track.

“to summarize so all of those numbers I think just get confusing I think it's better to just think about protein is an absolute number carbohydrates fat those are percentages of calories but protein is an absolute number so your minimum requirement is somewhere around 55 5 to 60 grams per day that's the absolute minimum for uh you know a 155 60 pound person uh we recommend around 120 grams per day for healthy adults”

Fasting beyond 24 hours is harmful for anyone over age 35 because extended fasting causes muscle loss that is typically permanent; younger individuals (under 25) can fast and recover the lost muscle through resistance exercise, but older adults cannot

“I don't think anyone over the age of 35 should ever fast because what we know is that if you're in your 40s 50s if you lose muscle mass chances are you can't get it back if you're in your 20s and you fast that's pretty good because you're still pretty anabolic and you can gain it back if you're in your 50s and you fast just like bed rest or breaking you know having surgery chances are that's a permanent loss of muscle”

Fake meat products contain approximately 25 different chemicals, most of which are not FDA-approved, and the health risks are unknown; unprocessed plant proteins like beans, lentils, and edamame are superior choices

“fake meat with 25 different chemicals most of which aren't FDA approved we have no idea their health uh risk is that better for you wow I don't think so”

NIH (National Institutes of Health) has historically declined to fund protein and amino acid metabolism research because they see no direct disease relevance; this created a funding vacuum that commodity groups (dairy council, beef board) filled to support Layman's groundbreaking leucine research that revolutionized protein understanding

“the primary funding for Metabolic Research studies disease they have no interest in studying food if I said I wanted to study uh exercise performance or I want to study I I sent in research grants to NIH for 10 years to study the leucine question which we now know has revolutionized our way of thinking about protein and the review that kept coming back they they did not fund my grants and they said well we don't know of any diseases related to protein so therefore it's not fundable I finally ended up having to go to craft uh the national Dairy Council uh the beef board groups that actually had an interest in protein”

A simple practical healthy diet framework is: divide your plate into three sections (protein, vegetables/high-fiber fruits, carbohydrates), make protein the primary choice, and ensure the carbohydrate section is never larger than the protein section

“we basically divide the plate into three uh sections and so front and center we say make your protein choice... then you make your uh next choice about vegetables and berries high fiber fruits... then your third section is what we call carbohydrates... your protein section in volume or your carbohydrate section can never be larger than your protein section so if you have a six ounce piece of of meat that means your carb section can never be more than a half a cup”