Donald Layman

  • Professor Emeritus of Nutrition in the Department of Food Science and Human Nutrition at the University of Illinois

Credentials

  • PhD in Human Nutrition
  • Fellow of the American Society for Nutrition

Education

  • PhD in Human Nutrition – University of Illinois

Affiliations

  • University of Illinois
  • American Society for Nutrition

Research Focus

  • Protein metabolism
  • Obesity
  • Diabetes

Notable Publications

  • Dietary Protein and Exercise Have Additive Effects on Body Composition during Weight Loss in Adult Women (2005)
  • Dietary Guidelines should reflect new understandings about adult protein needs (2009)
  • Protein in weight management: a review proposing protein spread and change theories (2008)

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Awards & Honors

  • Distinguished Service Award (2008)

Key Contributions

  • Dr. Layman has made significant contributions to the understanding of protein metabolism and its role in weight management and chronic diseases such as diabetes.
  • His research has reshaped guidelines for protein intake in adults.
Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 0:00 0
“there's no question in my mind that as far as muscle strength and hypertrophy the resistance exercise is probably at least 75 percent more important than the protein level”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 0:45 0
“today I sit down with Don Layman PhD to talk about protein”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:21 0
“some focus more on body composition and strength like Stuart Phillips some on metabolic Health like Don Layman”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 5:42 0
“muscle is a major source of glucose metabolism, it's a major source of fat fatty acid metabolism and if you have problems with blood sugar with blood lipids chances are your muscles aren't healthy”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 6:56 0
“you know do resistance training it's important to to maintain a good amount of muscle”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 9:51 0
“I don't personally think that resistance exercise is the key to metabolic Health”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 10:29 0
“I focus a lot on protein turnover so having good rates of protein synthesis responding correctly I think that's important”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 13:19 0
“isn't the answer healthy muscles is more of a mitochondrial and functional mobility as opposed to just big”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 14:01 0
“is it that hit training where you're getting up to that kind of very high intensity of your max heart rate where your providing the best stimulus to improve mitochondrial function or is it more of that moderate intensity kind of steady state longer exercise that you would say is better for a metabolic Health point of view from from a mitochondrial point of view”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 15:05 0
“closer to in the 60 to 70 percent range is where you probably would most people would Target again if you're if your goal is to be an Olympic Athlete then you want to train up in that 95 to 100 range if you're just trying to have healthy muscles what you want to do is be sure you're stimulating your heart rate maybe up in the 120 range you want to be doing resistance exercise size that's sort of the level that is probably going to be maximizing uh mitochondrial development and not necessarily relying all on glycogen to produce the activity”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 15:44 0
“a lot of folks these days are talking about Zone 2 training I'm not sure if you you've kind of heard that trendy term used but that's that's sort of sitting in sitting in that that zone of what you just explained there and a lot of endurance athletes do that to sort of I guess in Lay terms they say to become better fat burners and to improve their aerobic capacity”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 23:23 0
“The Single part of nutrition that's really most important is calorie control.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 21:43 0
“we can overcome that with the right kinds of exercise and protein and certainly flatten the curve.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 21:39 0
“these are somewhat in our DNA but we can overcome that with the right kinds of exercise and protein and certainly flatten the curve.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 27:40 0
“how much protein can you do with resistance exercise and lay down per day that number is about five grams”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 28:18 0
“in the middle of the night your liver has to be making protein or you die where you muscle becomes a reservoir of amino acid it's kind of sitting there and it's not being used while you're sleeping and so it actually donates the amino acids that the liver is using in the middle of the night”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 30:57 0
“muscle protein synthesis is at its lowest level when you wake up in the morning after fasting for 12 hours and it might be running at say a basal 20 30 percent and then with the right kind of breakfast you can have that more than double”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 34:02 0
“you and I have been talking about functional outcomes relative to strength or Mobility or metabolic function or you know and and that then ultimately longevity or mortality.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 35:00 0
“you might have a certain protein that you have after a workout and it gives you a great big spike up but then it comes back down and then another protein which doesn't Spike as quickly but stays up MPS stays up.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 36:31 0
“the problem with nutrition is we can't really control it that well and people don't like animal studies I frankly do like animal studies because you can control them.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 39:44 0
“we had a weight loss clinic at University of Illinois and we did a series of clinical weight loss studies basically as we started looking at people's diets and the Champaign-Urbana area what we found out was that about 65 of their protein was coming from animal sources and 35 percent was coming from plant sources.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 40:28 0
“we basically tailored meals and we came up that the minimum was around 30 grams per meal to have enough leucine to balance that out we were aiming at 2.5 grams of leucine is the minimum”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 41:34 0
“in Whey Protein leucine's about 12 and in soy protein it's a little less than eight percent so you can get to 2.5 grams with 23 grams of whey protein or 22 and it takes 32 with soy”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 43:04 0
“the RDA is set at 0.8 grams per kilo maybe 0.83 I think in grams per kilo in Australia it's a little bit different”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 46:46 0
“the efficiency of protein use goes down with aging so we know that the RDA is based on 25 year olds we know that it doesn't relate very well it's a 65 year olds”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 48:02 0
“not 0.8 grams per kilo actually 1.2 grams per kilo or thereabouts is better as we age to maintain function”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 48:21 0
“vitamin C at 60 milligrams per day the RDA it prevents scurvy but in the last two years of covid I would say most people have been taking five grams or more”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 50:54 0
“I usually Target the range of 1.2 to 1.6 and they can kind of fall in there wherever they want”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 52:34 0
“resistance exercise is probably at least 75 percent more important than the protein level”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 55:15 0
“we did a lot of weight loss studies with women uh and we found that there's a real hard line at around one gram per kg uh if they got below that we pretty much lost all the beneficial effects of protein or exercise or whatever”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 57:07 0
“as you go through each of those decades your calorie needs are going to go down so that means your protein needs to be a higher percentage of your diet no matter what”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 59:42 0
“leucine supplementation may be worth thinking about too”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:01:33 0
“all of this is the branch chain amino acid leucine for years since the 1930s we've known that the branch chain amino acids are not metabolized in liver all of the other amino acids are metabolized in liver but these three branch chain leucine, valine and isoleucine get sent out primarily to skeletal muscle so the body has learned to sense it it is senses it as a indicator of protein coming in and basically when that leucine concentration goes up from basically fasting levels to about three times fasting levels uh it triggers a complex inside muscle known as mtor and that's the main sort of Central regulatory function that triggers all these sort of initiation factors and we trigger maximum protein synthesis.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:02:31 0
“what we now know is that there are actually Four signals that the muscle is integrating at the same time this is very different than liver it's integrating protein by sensing leucine, it's integrating growth hormones insulin and igf-1, it's integrating energy ATP and it's integrating stress resistance exercise when all four of those are correctly balanced it triggers mtor and muscle protein synthesis so all of those it's looking at”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:03:03 0
“but once you stop growing the hormones no longer control that system and now it's dominated by meal quality and leucine is the primary key growth hormone and it's a growth hormone is one of the the hormones insulin and igf”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:08:38 0
“in these studies where they do protein restriction an inevitable outcome of that is simultaneously there is calorie restriction and then it becomes difficult to say well what do you attribute the change in lifespan too is it the differences in amino acids or is it of the fact that compared to the control that animal is now eating far less calories”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:10:07 0
“you're gonna have to feed them discrete meals of the same calorie level with the two different proteins for two and a half years”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:10:42 0
“we know that obesity shortens longevity no question about that”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:11:21 0
“if you factor out the people who ate hamburgers at fast food every day and basically find the people who had protein intakes that had reasonable vegetable intakes it all washes out and eggs become a positive”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:16:35 0
“I want to chat to you about cardiovascular disease because something else that I think about personally here is I've got cardiovascular disease in my family. I'm aware that it's the number one probably likely reason I'm going to die prematurely.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:17:02 0
“AHA guidelines for preventing cardiovascular disease have a very clear statement that says to choose healthy sources of protein and they're not anti-animal protein but they talk about lean meats, but then below that healthy protein they have a very clear line that says mostly protein from plants.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:19:36 0
“We don't need a more plant-based diet, we need a diet with better plants.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:21:09 0
“The primary problem with the standard American diet or standard Western diet is the fact that what is it 60% of calories are coming from ultra-processed foods.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:22:40 0
“unhealthy diets are unhealthy... are there healthy diets that are primarily animal based that have good fiber contents and good vegetable content? I would argue there are. Are there unhealthy vegetarian diets? I would argue there are just by saying it's plant-based doesn't make it healthy.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:23:25 0
“I think the way that often it's done online is different to kind of what he describes which is a very low saturated fat kind of lean animal protein style diet with high fiber.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:26:49 0
“I go for two to three meals a day that have 40 plus grams of protein in it that's sort of where I start meal distribution.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:28:55 0
“when you wake up you are in a catabolic muscle condition and until you have a meal that has a significant amount of protein, that catabolic state continues.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:28:57 0
“30 or plus grams of protein you're going to stay in that catabolic condition.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:34:46 0
“I don't think there's any real data that supports a bolus before we've done some of that type of research in animals where we could really control it and we never found any effect.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:35:00 0
“we were the first to publish protein after research because what we were looking for is conditions where we would doubt so we know that overnight fasting down regulates mtor and protein synthesis so we were looking for other conditions exhaustive exercise will also do it so we thought okay so this is where we can test you know what's the controlling mechanism and that's actually where we discovered the leucine mechanism”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:36:24 0
“achieving an optimal sort of total protein sounds like that's going to be very important”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:36:15 0
“protein immediately ahead of exercise I don't see any data that convinced me that that's useful”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:36:54 0
“I think your your last meal of the day let's call it dinner in the United States I think that should be a big meal also.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:37:30 0
“one of the things we know is one of the major issues in obesity is snacking having more food experiences per day”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:42:25 0
“you'll absorb whatever you eat can be a hundred grams um you can't utilize it well the efficiency probably goes down as you go higher um so you know 30 grams might be you know a cost benefit you might get the maximum effect for the fewest calories so if your issues obesity that may be an issue but if your issue is I want to gain muscle mass then 50 my 55 might be a better Target for you”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:44:08 0
“one of the things we know for sure is that an ice bath would slow down gut motility so my guess is they simply their gut they're gastric emptying their gut motility they're just not absorbing it very fast”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:45:26 0
“protein synthesis in the muscle will shut down after about two to two and a half hours even if leucine's still up so there is something called muscle full or refractory period that once muscle runs for a while it stops”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:49:24 0
“Kidney Health comes up and and I think there's sort of two two sections to this there's one that says you know high protein diets are bad for people with chronic kidney disease and then there's the the next section which is that high protein diets are just bad for kidneys in general.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:50:50 0
“The question then becomes does protein cause it and that has been pretty clearly shown not to be the case in fact the diet the National Academy of Sciences when they were putting together dri specifically concluded that low protein diets actually are a bigger risk to kidney failure than high protein diets.”

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Protein Amount, Quality and Timing – with Dr. Donald Layman | The Proof Podcast EP 236
Optimal Protein Intake for Health and Muscle Function Explained 1:54:10 0
“I think that a healthy diet has healthy forms of protein they can be plant or animal uh and it has helped healthy plants there are very unhealthy plant-based diets.”

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