Protein — Everything You Need to Know
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Summary
Proteins, along with fat and carbohydrates, make up one of the three basic macronutrients of the human diet. Yet for something so fundamental, a lot of confusion exists about protein. What's the best kind? How much do you need? When should you eat it? Here to clear up some of that confusion, Dr. Don Lehman, professor emeritus of nutrition and one of world s foremost researchers on the subject of dietary protein, explains why animal based proteins are superior to plant based proteins, why collagen is worthless, how much protein you really need to consume, whether it depends on your activity level and age, what happens when kids don t get enough protein, the optimal times of day to eat protein, who needs to consume protein right after a workout, and whether you can get enough in your diet if you do intermittent fasting.
Transcript
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Brett McKay here and welcome to another edition of the Art of Manliness podcast.
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Protein along with fat and carbohydrates make up one of the three basic macronutrients of
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the human diet. Yet for something so fundamental, a lot of confusion exists around protein.
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What's the best kind? How much do you need? When should you eat it? Here to clear up some
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of that confusion is Don Lehman, professor emeritus of nutrition and one of the world's
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foremost researchers on the subject of dietary protein. Today on the show, Don explains why
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animal-based proteins are superior to plant-based proteins, why he thinks collagen is worthless,
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how much protein you really need to consume, whether it depends on your activity level and age,
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what happens when kids don't get enough protein, the optimal times of day to eat protein,
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who needs to consume protein right after a workout and who doesn't, and whether you can get enough
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protein in your diet if you do intermittent fasting. We enter a conversation with why Don
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thinks increasing protein consumption can be the most effective way to lose weight.
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After the show's over, check out our show notes at awim.is slash protein.
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Yeah. So you are a researcher that has done a lot of studies on nutrition, particularly
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dietary protein. And I want to talk to you about protein today because I think a lot of people have
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questions about protein. What's the best kind of protein? How much protein should I really be eating
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in a day? When should I eat protein? And there's a lot of ideas floating out there in the popular
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press. But let's start off with a sort of a brief overview of how our bodies use protein,
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right? So like, I just had some chicken breast before we get on the show. I ate that piece of
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chicken. How is my body going to use the protein from that chicken?
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Yeah, you're right. I think protein's a complicated topic. And I think maybe we can simplify it a little
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bit. So your chicken breast, I like to remind people that protein is kind of like a vitamin pill.
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We really don't need the pill. What we need are the 14 vitamins inside of it. We don't talk about
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the color of the pill or the digestibility of the pill. We talk about the vitamins. And that's
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really what protein is. It's really just a food delivery system for amino acids. So when you eat
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that chicken breast, the very first thing your body does is break that protein down into individual
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amino acids. And there are 20 of them that are naturally occurring. Nine of them, our body can't
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make. We call them essential or indispensable. We have to have them in a daily supply. The other 11,
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the body can make it. It's sort of if you have enough of one amino acid, you can make another one.
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So nine are essential, 11 are considered non-essential because we can make them. So once we digest it in our
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GI tract, in our intestine, the body then absorbs them. How do we make them into protein or in the
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body or muscle protein? Well, the first thing to recognize is that as these amino acids are getting
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absorbed into the body, the body begins to use them. And about 50% of every amino acid that you take
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in in a diet gets used before it ever gets to the blood. It gets used by the lining of the intestinal
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tract, by the liver. And so only about 50% ever get to the blood. And of those, then the body will
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use some for energy and some can get made into protein. So in muscle, about one out of every seven
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amino acids going into a new muscle protein comes from the diet. And the other six actually are getting
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reused. So the whole system gets pretty complex at that point. But sort of the point of all that is
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that a single amino acid in that chicken breast you ate, it's kind of hard to track it directly into a
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new protein and muscle. So that's sort of the complexity. And we can go from there as to, you
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know, how do we sort out the need and different quality and protein? But that's sort of how the body's
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using them. Okay. So protein is the delivery for amino acids. Exactly. And protein doesn't just make
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muscle tissue, but it also makes other tissue in our body. It's like, I think fingernails, hair
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needs protein. Sure. And in the body, all adults and even children, you know, anyone over the age of
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about 16 has to make 250 to 300 grams of new protein in the body every day. Proteins that are in your liver,
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we're replacing them almost hourly. Proteins in the blood might last 15, 16 days. Proteins in the muscle
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might last 30 or 40 days, but we're continuously replacing those. In fact, if you sort of look at it on a
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total body basis, we replace the equivalent of every protein in our body about four times per year.
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So there's this big turnover going on all the time. And that's important as we repair our body and sort
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of in the aging process, repair and replacement is really important. Let's talk about protein and
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muscle. People typically, that's what they associate. I'm going to consume protein to grow muscle tissue.
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And the process where our body turns amino acids that we've consumed into muscle tissue,
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that's called muscle protein synthesis, correct? Right. So protein synthesis is a term of every
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tissue, whether you're talking about the heart or the brain or the liver or muscle. So it's protein
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synthesis. And as you point out, people have kind of focused on muscle, but in every tissue, it's the
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same. Okay. So let's talk about the type of protein we consume. How does the type of protein we consume
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influence protein synthesis? Yeah. So again, we talk about protein is just a food delivery system
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for amino acids. So the type of protein really reflects the balance of amino acids. And as I said
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at the beginning, we absolutely require the nine essential amino acids. And so if you look at different
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proteins, whether you're talking about a dairy protein like whey protein or a plant protein like soy
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protein, you look at the distribution of those nine essential amino acids, and every protein's a little
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different. What we know though, is that proteins that come from animal sources, and in this case,
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I'll include eggs and fish, all sort of animal sources versus plant sources. Proteins that come from
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animal sources always have a better distribution and a higher distribution of those essential amino
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acids. If you want to think about it, plants have amino acids for the sake of plants. They're not
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assuming they're going to get eaten. So they have it to make roots and stems and flowers and seeds,
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which are pretty different than brains and hearts and skin and muscle. So the way to think about it is,
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you know, plant proteins have amino acids to making plant products, you know, plant structures.
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And so I think one of the research you found, I've read this other places, that
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part of the problem with plant-based proteins is that they don't have enough of a particular type
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of amino acid that helps kickstart protein synthesis, correct?
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Right. So of those nine essential amino acids, there are three that we often say are limiting
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in plants. And those three are lysine, methionine, and leucine. Of those three, one that I've studied
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a lot is called leucine. And what we discovered was that leucine has a very unusual role in triggering
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muscle protein synthesis. For reasons we don't fully understand, the body has evolved to recognize
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the increase in leucine in the blood as a indicator that the meal was well enough balanced to trigger
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muscle protein synthesis. Another way to sort of think about that is in the liver, you have to be
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making proteins 24 hours a day. If you're not making them in the middle of the night, you're going to
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die. I mean, you just have to be making them. Same with the brain or the heart. In muscle, we only do
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it when we have a meal that is adequate. We call it an anabolic response to a meal. And for whatever
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reason, the body evolved to recognize leucine as that signal that the meal is adequate. So leucine is a very
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important amino acid for defining what we call protein quality. Is there enough leucine to trigger
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muscle protein synthesis? And that's why people who do a vegetarian diet, they have a harder time
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getting the necessary proteins. The plant base doesn't have enough leucine.
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Right. So if you look at, just for example, if you look at whey protein, which is a protein that's
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become very popular with people who are trying to build muscle, if you look at the amino acids in
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whey protein, 12% of those amino acids are leucine. But if you look at a grain like quinoa, which people
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think of as a really good plant-based protein, leucine is 6%. So you have to have twice as much quinoa
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protein to trigger protein synthesis. That translates into something over seven cups of quinoa at a meal
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to trigger muscle protein synthesis. So from a calorie standpoint, from a volume standpoint,
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it's hard to eat enough plant-based protein to get to the leucine number.
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Yeah. It sounds like you'd have a lot of gas. You'd be bloated.
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Yeah. I mean, you get a lot of fiber. I mean, quinoa, in my mind, quinoa is a great carbohydrate
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source that happens to have good protein in it. So it's a great fiber. It has good nutrients. It's
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a great food, but it's a pretty poor protein source alone. So you really need to have something else
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with it, whether you're going to mix, say, soy protein with it or tofu, or you need higher protein
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Can you supplement with leucine to kickstart protein synthesis?
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You can at some level. We have done that sometimes in situations like somebody is ill in a hospital
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and they just can't eat much. We've shown and others have shown that if you take in 15 grams
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of protein, but then supplement that with leucine, you can get up to that threshold to stimulate muscle
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protein synthesis. We know that you need to have around three grams of leucine in the meal.
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So you could get say one and a half from plant-based proteins and add in another one and a half as a
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supplement of leucine and you can get to that three gram level.
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Okay. So in terms of delivering amino acids, animal-based is going to be superior to plant-based
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proteins. Of the animal-based proteins, are some better than others? We're talking like meat or egg or
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whey. I think you have to decide what your goal is. If your goal is to have a breakfast that stimulates
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muscle protein synthesis, and that's really your only goal, then whey makes a perfect shake because
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it's very high in leucine. You can stimulate muscle protein synthesis with only about 23, 24 grams of
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protein. On the other hand, if you're thinking about a balanced diet, something like beef protein is a
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great source because not only is it a good source of the essential amino acids like leucine, but it's
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also very rich in iron and zinc and selenium and B6 and B12. So you have to think about what your goal
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is. Eggs is another example where the egg is a very balanced nutrient overall, vitamins, minerals,
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as well as protein. So you kind of have to think about the balance there. Fish, for example, is a
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very good protein source, but the vitamins and minerals tend to be lower. So again, what's the
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balance? And I think that's why nutrition, we've always said, well, have a varied diet. Don't believe
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that, well, the only protein I should eat is fish or the only protein I should eat is white meat
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chicken. Those are good protein sources, but actually low in other nutrients.
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Yeah, I think that's interesting. You got to think about the whole picture, not just protein.
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Yeah. You know, in general right now, we're beginning to focus more on what we call the food matrix.
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You know, we've had a, what we might call a reductionist approach for a long time where we think
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about a food, well, does it have enough vitamin C or does it have enough vitamin D or does it have
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enough of amino acids? But now we're trying to think about it more as a meal complex and a whole
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diet. Well, speaking of this idea that protein is just a delivery capsule for amino acids, we talked
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about the fact that you can supplement leucine. Can you get the benefits of all the amino acids just by
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taking an amino acid supplement? You can. That's incredibly expensive to do, to take in enough
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protein to, you know, to get a hundred grams of amino acids per day would be an incredibly expensive,
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but people have certainly shown it in hospital situations. You know, people who can't eat,
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we can do an IV into their arm or whatever and supply those amino acids. So that certainly can be done.
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My attitude about that is a little like people self-supplementing with vitamins. Do you really
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have enough knowledge to do the chemistry that resembles food intake that has evolved over a
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million years? You know, I don't think most people have the resources or the knowledge to really do
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supplementation. Okay. What about collagen proteins? I've been seeing a lot about that. I'm at Whole Foods
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and I see a lot of rows of collagen proteins. What's the quality of collagen proteins?
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Collagen, by any measure, is the single worst protein you could ever see. Okay.
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It's deficient in at least four essential amino acids. It's one that I always sort of scratch my
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head at. I look at all these testimonials out there that people think that collagen's great,
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but the reality is from a scientific research standpoint, it's awful. I think it's a total
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waste of money. So obviously I'm really negative about it. On the other hand, there's a lot of
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people who believe in it. So, you know, I sort of remain open-minded, but at the same time,
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I've seen no data to make me believe that it's anything more than just a nitrogen source.
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When you look at the true protein requirement, it's actually two parts. The first part is getting
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the nine essential amino acids, and the second part is getting additional nitrogen. That nitrogen
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we refer to as nonspecific. And I think, for example, collagen is nothing more than a nitrogen source.
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So, you know, if you have a relatively low protein diet and you want to supplement it with expensive
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collagen, I guess that works. But if you're just trying to get adequate protein, collagen's a
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lousy source. Okay. So the takeaway there, quality, the type of protein, animal-based is going to be
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your best bet to get all nine of the essential amino acids in the right dosage to kickstart and
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have muscle protein synthesis going on. If you're doing a vegetarian diet, you might have to supplement
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with a higher source protein, like a soy protein. And then, yeah, wasting your money with collagen
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and amino acids. Nature's already got the pill for you. It's animal-based protein. So just go with
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that. Yeah, that's exactly right. And people, you know, will often say, well, he's really negative
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about vegetarianism. That's not really the case. My problem with it is that if you look at the data,
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all the survey data, what you see is that vegetarians typically have lower protein intakes and they have
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lower protein quality. So that's a risk, you know, and I think that if you're making that lifestyle
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choice, you need to understand it. My personal preference would be a blended. I don't think it's
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all or nothing. I think you can be more plant-based. I think that's great. But using fish or eggs or
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cheese or something to make it more balanced, I think is a better choice. So, you know, I have no
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problem with being plant-based. Being totally vegan is a real challenge. You're sort of forced to go to
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ultra-processed foods. You need to have things like soy protein isolates or pea protein isolates to
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supplement your diet. Or like you said, maybe essential amino acids, which are very expensive.
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So, you know, it's just a challenge. And my fear is the average adult doesn't have the knowledge to
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make that work. All right. So, let's talk about how much protein we should be consuming because there's
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a lot of different numbers out there in the popular press. What's the typical amount that's
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recommended? I think it's the National Academy of Medicine has put out like a recommended daily
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amount. What's the amount that they recommend and what has your research shown to be an optimal amount
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of protein? Okay. So, the National Academy of Sciences and the Institute of Medicine sort of sets
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dietary guidelines. So, let's take a non-protein example. So, vitamin C, with every nutrient,
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the Institute of Medicine recommends a range for the nutrient. So, for vitamin C, the low end of the
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range, which we call the RDA, recommended dietary allowance, is 60 milligrams. But we know that you can
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go to an upper range with vitamin C of maybe up to 10 grams per day, you know, more than 10 times the
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minimum RDA. So, we know that the RDA prevents a deficiency, scurvy, but when you get a cold or,
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you know, concerned about COVID or something like that, people will take 500 milligrams or 1,000 milligrams.
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So, the difference between the minimum and the optimum. So, let's apply that to protein. The Institute of
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Medicine sets the minimum, the RDA, at 0.8 grams per kg, which is around 0.3 grams per pound. But it says
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there's a range up to some upper limit, and we know that is up around a gram per pound. So, a big range
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there. What we now know is the optimum range for most adults is somewhere between about 0.5 and 0.7
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grams per pound. 1.2 to 1.8 grams per kg is the way we talk about it. So, again, we need to recognize
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that for every nutrient, there's a range of intake. The RDA, which people hear about, is the minimum to
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prevent a deficiency. In fact, it's defined at a level where 97% of the people don't show a deficiency,
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but 3% will actually show a deficiency. And if we look at national survey data, what we know is that
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in women over 60 years of age, 40% are actually below the RDA. So, in general, women in particular
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are particularly low in their dietary protein intake. Men are a little bit higher, but still
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not up in the range that we think is optimal. Okay. So, just to put some concrete numbers to
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this, okay, the RDA is the minimum you need to make sure you're not wasting away. So, let's say
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you're a 200-pound man. Would you say the RDA was about 0.36 grams? Yeah. So, the range of intake in
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the United States, the RDA, depending on body weight, is sort of between about 56 and 66 grams
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per day. Average intake in the United States is around 80. We think that most adults should be
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above 100. And again, it's body weight. So, you know, if you take a 250-pound male, that person will
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have twice the amount of protein as a 125-pound female. That's crazy that most people are only
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getting 80 grams of protein a day. That's the average based on the national surveys. Again,
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men a little higher, maybe a little closer to 90, and women a little lower, closer to 70. But the
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average is 80. Okay. Do protein requirements change for men and women? So, if you're a man,
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do you need more protein than women? It's based on lean body mass. It's based on body weight. So,
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men typically are going to weigh more than women, so they need more protein. But it's,
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you know, a 150-pound woman and a 150-pound man would have essentially the same requirements.
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Okay. Slightly different because typically women will have a little more body fat, a little less
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lean body mass. But in essence, the requirements are the same based on body weight.
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Does the requirement change or the optimal amount change if you're physically active?
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That's a good question. Interestingly enough, people generally assume that, well, if I'm lifting
00:22:00.580
weights and building, you know, trying to build body mass, I need more protein. It's actually
00:22:06.380
endurance exercise. We know that endurance exercise burns about 10 grams of protein per hour of exercise,
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like running, a marathon runner, for example. So, if you go out and doing, you know, three-hour runs,
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by definition, you need 30 grams of more protein than normal.
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Okay. So, whenever you exercise, you're going to need more protein. And that's not just for
00:22:29.120
weightlifting. I think that's really interesting. If you do a lot of endurance sports, you need to be
00:22:33.680
increasing your protein intake a lot. Speaking of, you know, consuming protein because you're lifting
00:22:39.060
weights to get stronger, I think a lot of people have this idea that, well, if I megadose on protein,
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it's going to help me build more muscle tissue. But your research has found that probably at a
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certain point, consuming more protein won't have any benefit.
00:22:54.380
Yeah. Our methods aren't great for determining sort of small differences between protein intakes.
00:23:01.920
What we find is that a lot of bodybuilders will look at an intake of like a gram per pound,
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which translates into about 2.2 grams per kg. The research shows we really can't tell any
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difference between 1.8 grams per kg and 2.2. So, you know, most bodybuilders are probably over-consuming
00:23:24.760
protein. But again, you know, they're looking for sort of a maximum effort. So, I don't see any problem
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with that. But the research doesn't really support any real benefit above about 1.8 grams per kg.
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And again, I think that translates into about 2.8 grams per pound.
00:23:43.820
Okay. So, yeah, I consume right now, I'm doing about a gram per pound. So, I get about 200 grams.
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That's very common for people who are trying to lift weights. And again, you have to think about
00:23:58.860
protein in the context of the whole diet. So, if you don't eat 200 grams of protein, what are you going
00:24:05.100
to eat? And a lot of people say, well, I want to be sure I don't eat the carbohydrates because that
00:24:10.440
causes me to retain more water and I don't like the way I feel or whatever. I have, you know,
00:24:16.040
tendency toward diabetes. So, you know, from a pure muscle building standpoint, we think that around
00:24:23.340
0.8 grams per pound is totally adequate. But there's nothing wrong with a gram per pound if
00:24:29.280
that sort of suits your needs. What happens with the excess protein that your body doesn't need?
00:24:35.040
Excess is an interesting concept. Let's think about you in terms of a gram per pound per day. You know,
00:24:41.460
how much muscle mass are you gaining this week? Probably nothing. So, if you're eating 200 grams
00:24:50.340
of protein per day, where is it going? Basically, you have to burn every one of those grams, the
00:24:56.660
equivalent of every one. So, basically, whether you eat 60 grams of protein per day or 200 grams of
00:25:04.360
protein per day, you're going to burn it all for energy. You use it for protein synthesis,
00:25:09.720
but at some level, you have to get rid of every gram or you have to store it in some way,
00:25:15.880
which means you're gaining weight. So, again, people think about burning the excess. The reality
00:25:22.160
is, I mentioned at the beginning, 50% of the amino acids that come into the body are burned in the GI
00:25:28.320
tract or the liver before they ever get to the blood. So, this whole concept of burning the excess
00:25:33.860
is kind of a vague concept because we're always burning everything we eat.
00:25:38.280
So, we're going to take a quick break for your word from our sponsors.
00:25:45.140
And I also, I think it's important to note that you highlight research that eating a high-protein
00:25:50.960
diet, it's not going to damage your kidneys. I mean, that's an idea that's out there, right?
00:25:54.460
Like, too much protein is bad for you. If you do have some sort of kidney disease,
00:25:59.120
a high-protein diet might be an issue. But if you're healthy, eating a lot of protein won't do
00:26:03.640
anything to you. Basically, like you said, any excess protein will be used in the body for
00:26:08.300
something else. So, yeah, I think the big takeaway there overall is that if you're a physically active
00:26:12.840
male, like 0.8 to 1 gram per pound of body weight is probably what you're looking at.
00:26:19.640
So, that's a target where the science shows, you know, has really good data. We think that's
00:26:25.760
the upper range that makes any sense. And frankly, the research shows 0.8 is probably adequate,
00:26:32.480
but there's nothing wrong with going to a gram per pound.
00:26:35.600
All right. So, if you're a 200-pound man, that would be 160 grams per day.
00:26:40.060
Right. You know, up to 200, as you pointed out.
00:26:43.740
And people, I think that's a lot of protein. But I mean, it's not... Once you kind of figure
00:26:46.980
things out, you know what's a high source of protein. And it's easily the supplement with
00:26:51.920
a whey protein. Whey protein is fantastic. It's cheap. And you can get a lot of great protein
00:26:58.080
Yeah. I think most people find that amount of protein pretty hard to consume. Most women,
00:27:05.040
we've done a lot of research with women, particularly looking at weight loss. We find it
00:27:11.000
extremely difficult to keep women above 100 grams per day. I personally eat probably 100 to 120 per
00:27:18.260
day. I weigh about 160 pounds. So, you know, again, I think if you're motivated toward bodybuilding,
00:27:26.960
that's great. But again, we think the healthy range is sort of in that, you know, a lower end
00:27:35.020
of about 0.55 grams per pound up to a gram per pound. So, falling within that range is probably
00:27:43.660
okay, depending on your personal goals. Something I've heard is that as you get older,
00:27:49.720
you know, to your 50s, 60s, 70s, 80s, you have to consume more protein. Is that true?
00:27:55.680
What we know is that the efficiency of protein use goes down with age. Where does that start?
00:28:03.220
We think it starts somewhere around 40, maybe 35. We know that when you're still growing,
00:28:10.540
your body is kind of driven by hormones. So, when you're in your teens or in your 20s,
00:28:15.940
your body is making protein driven by growth hormone, IGF-1 insulin. Once you stop growing,
00:28:23.900
now you're going to the maintenance phase. We know that everything we've been talking about,
00:28:28.500
all of this meal balance kind of thing. That starts to come into play in your mid-30s. So,
00:28:34.780
your point about the efficiency going down, we think that starts in the 40s. So, people need to
00:28:40.520
be making adjustments in their 40s. And certainly, by the time you get out into 60 and 70, now you're
00:28:47.680
confronted with the issue that your total calorie needs per day begin to go down, but your protein need
00:28:53.920
is at least as high as when you were 16 or 25. But now you need to get it in less total calories.
00:29:02.360
So, the quality of your diet needs to go up. Your nutrient density needs to go up. You need to get
00:29:07.840
more amino acids per calorie you eat. And it probably, you know, is it higher than when you're 25?
00:29:15.800
It might be. It might actually be higher. I think it's one of the reasons why you tend to find more
00:29:22.120
vegetarians who are between 20 and 40 than you do between 60 and 80. You're just really hard to pull
00:29:29.740
that off to get the protein you need with the reduced calories.
00:29:35.280
So, just correct me if we're on here, make sure I understand. So, as you get older, does our body just
00:29:38.780
become less responsive to protein and we just have to consume more of it to kickstart that protein
00:29:43.920
synthesis? Exactly. When you're young, muscle protein synthesis and a mechanism we know of as mTOR
00:29:51.940
is very sensitive to insulin. And so, you grow because of hormones. Once you get beyond mid-30s,
00:30:00.780
now it becomes sensitive to the quality of the protein and particularly that amino acid leucine. So,
00:30:06.520
we're changing how the body regulates muscle protein synthesis. And as we get older,
00:30:13.360
it becomes more and more sensitive to the leucine amount.
00:30:17.960
Okay. So, any recommendations there, just concrete numbers? If you're, say you're 70 years old.
00:30:23.820
We know that the leucine trigger amount is about three grams. Probably, you begin to get a response
00:30:31.800
at like 2.5 grams. Some people have used up to four. We usually use the number of three grams of
00:30:38.720
leucine as your target to activate that system. So, if you look at a mixed diet, then let's say
00:30:46.000
you're having a meal that has some animal protein, some plant protein. We usually use the number of
00:30:53.540
around 8% leucine in a mixed meal. So, that means your minimum threshold, you may have seen the meal
00:31:00.840
number of like 30 grams, 30 to 35 grams per meal. That's assuming leucine makes up about 8% of the
00:31:08.300
protein. So, to get to 2.5 to 3 grams, you need at least 30, 35 grams of total protein. So, that's
00:31:15.360
where that meal number comes from. Okay. So, to recap, as you get older, your body becomes less
00:31:21.600
sensitive to protein. So, you may need to increase protein intake to make up for that. So, I think the
00:31:28.160
big takeaway there is just, yeah, as you get older, be more aware of your protein and then
00:31:33.300
think about how much protein you're getting at each meal. And we're going to talk more here about
00:31:37.620
protein distribution. But let's talk about kids. What do we know about the protein requirements for
00:31:43.400
children? So, they change during aging. So, in the first year, the two years, the protein requirement is
00:31:52.520
that 2.2 grams per kg, so a gram per pound. So, as a child, as a very young child, it's now what we're
00:32:00.860
talking about for older adults. Okay. The belief then is as the rate of growth slows down, it slowly
00:32:08.260
goes from 2.2 down to 0.8 for a 16-year-old. So, there's that shifting process. I think the research
00:32:18.660
is beginning to question, does it really go down like that? We know that, you know, your rate of
00:32:24.920
building protein is slowing down, but you're building and replacing so much protein that actually
00:32:31.220
isn't growth. So, I think we're beginning to question that. One of the important things about
00:32:37.340
children versus adults is for adults, we're now talking about the meal distribution of protein
00:32:43.480
and leucine. So, we talk about having 35 grams of protein per meal to get enough leucine. That
00:32:50.720
doesn't seem to be true for children. Children will respond at very small meals. If a child has
00:32:57.260
5 grams of protein at a snack or 10 grams for protein for breakfast, they'll grow perfectly fine.
00:33:05.280
Muscle protein synthesis is perfectly fine. So, an average 10-, 12-year-old is probably targeting around
00:33:11.260
50 grams per day. And that can be distributed kind of in any way they want. It's not meal-specific like
00:33:18.020
it is for adults. Okay. So, with kids with body weight, what's the ratio? How many grams per
00:33:24.120
kilogram are you looking at for a child? Is it the same for an adult? So, again, it's, you know,
00:33:28.960
the RDA for children over like 6 is that, you know, 0.35 grams per pound. Okay. So, it's the RDA.
00:33:38.920
0.8 grams per kg. Okay. And again, that's just the minimum. Do we know what happens if kids don't
00:33:45.180
get adequate protein in childhood? Does it have any long-term effects? Oh, yeah. I mean, the biggest
00:33:50.640
international problem with malnutrition is availability of protein. So, with growth stunting,
00:33:56.120
there's a lot of, you know, early in my career, I did a lot of international work with children and
00:34:01.740
malnutrition and growth stunting. And so, we know that if children don't develop the lean body mass
00:34:09.600
they should when they're young, there's a real high risk that they're going to be obese. If they don't
00:34:16.680
have the lean body mass, they'll tend to deposit more body fat. So, one of my concerns now is that,
00:34:23.780
you know, as mothers are hearing about everybody should have a more plant-based diet,
00:34:28.960
and they start translating that to children, there's a real risk that we're going to induce
00:34:34.840
malnutrition in children. They're just not going to grow correctly. And that's a long-term risk.
00:34:40.520
One of the examples I like using is if you take a common wheat cereal and the serving size might be,
00:34:49.940
let's say it's a cup, has four grams of plant protein, say a wheat protein. If you look on the
00:34:55.600
label, they'll say, well, you take that cereal and you mix it with six grams of milk, we now have 10
00:35:03.100
grams, and that turns out to be exactly balanced for essential amino acids. But now we're hearing
00:35:09.060
about plant-based proteins, and so they say, well, switch to soy milk. Well, we're not telling people
00:35:16.360
very well, and I don't think they get, is that soy milk is deficient in the same amino acids that the
00:35:22.860
wheat cereal is deficient in. And so to get a balanced protein mix, you have to have over 25 ounces of soy
00:35:30.320
fluid, milk, to balance that meal. 25 ounces, we're nearing a quart. And if you go to almond milk, which is
00:35:38.080
even worse, now you need over 50 ounces to make that work. So mothers need to recognize that basically if
00:35:46.200
they're doing that with plant-based milks, they're creating an amino acid imbalance. And while I said
00:35:52.480
that younger children can get along with protein at any meal, they still have to have a balanced ratio
00:35:59.200
of essential amino acids. So my comment earlier is that I'm not sure most adults have the knowledge of
00:36:07.480
how to create totally vegetarian diets. They might be able to do it, but very few can.
00:36:15.360
Okay. So kids who don't get enough protein in childhood, they're not going to develop lean muscle
00:36:19.720
mass. And as a consequence, they might develop more adipose tissue, which could result in type 2
00:36:26.680
diabetes, metabolic syndromes. Exactly. So that's what we saw with the international work. If the
00:36:33.600
children are gross stunted, did not develop the lean body mass during their early, you know, their
00:36:40.240
first 14, 15 years, then they're prone to developing obesity. And as you said, all of the diseases that
00:36:48.220
go with that, diabetes, heart disease, et cetera, they're much more prone to those kinds of things.
00:36:54.600
Let's shift to protein timings. That's something I think a lot of people have read about, that there's
00:36:58.840
certain times of the day that it's better to eat protein. Is there anything to that idea? Like, you know,
00:37:03.460
should you consume protein after a workout? Is morning or dinner better time for protein?
00:37:08.920
So let's sort of complete the comment with children. As I wanted to emphasize, timing doesn't
00:37:14.620
seem to be as important for children. So when we talk about timing, we're talking about adults.
00:37:20.780
What the research shows is that probably the first meal of the day may very well be the most
00:37:28.700
important. We know that we're coming out of an overnight fast. We know that all of the mechanisms
00:37:35.120
for muscle protein synthesis are shut down. And until you eat a protein meal that has enough leucine,
00:37:42.620
till you get to 35 grams of protein at a meal, your muscle stays what we call catabolic. It's breaking
00:37:50.220
itself down. So we think that the first meal is critical. We also think that a later meal,
00:37:57.240
what we don't really know is the, you know, how important is the middle meal? So, you know,
00:38:02.860
something you might do in middle of the day, nobody's really studied that. So we don't really
00:38:07.200
know, but we do, we know for a hundred percent certainty that that first meal, and I'm, I'm sort
00:38:12.620
of avoiding calling it breakfast because that implies that it needs to be super early or something,
00:38:18.040
but whenever you choose to eat it, whether it's seven in the morning or 11 in the morning,
00:38:22.880
that first meal needs to be high protein. You mentioned after exercise, we did a lot of research
00:38:29.580
and others have done a lot of research with exercise because exercise is sort of a catabolic
00:38:36.640
period. Protein synthesis is depressed. And so we're looking at recovery. How's the best way to build
00:38:42.500
muscle? The thing to remember about that is almost all of that research is done with untrained
00:38:49.280
individuals doing an acute exhaustive exercise. What we know is that the more trained you are,
00:38:57.860
probably the less important that becomes. So if you're just beginning an exercise, you're out of
00:39:03.940
shape, you're just beginning having protein, you know, 15, 20 grams after your exercise within the
00:39:10.860
next hour or so probably is a useful way to recover. But if you're well-trained doing the same thing
00:39:17.940
week after week, when you have your protein after an exercise, probably doesn't make much difference.
00:39:25.200
It's really the total amount per day. Most extreme bodybuilders will probably take in protein
00:39:32.400
at least four times a day. So if you want one of those to be after exercise, that's great.
00:39:38.380
But if your next meal happens three hours after exercise, that's fine too. So I think the whole
00:39:45.220
after exercise thing has been distorted a little bit, all of the research has been done with
00:39:51.140
untrained people doing exhaustive exercise. So if you're well-trained, the timing's probably not
00:39:57.200
nearly as important. So you mentioned to kickstart protein synthesis with that first meal, you got to
00:40:01.980
have 35 grams of protein. Is there any other research about distribution of protein throughout
00:40:06.440
the day? So beyond that first meal, does it matter how you distribute your protein?
00:40:10.020
It doesn't really seem to. There's pretty good data that having a larger meal later in the day
00:40:17.820
is important. So like a dinner meal that has maybe 50, 60 grams of protein. And there's a little bit of
00:40:25.300
research, Luc van Loon in the Netherlands has shown that for individuals, again, interested in bodybuilding,
00:40:32.420
having a fourth meal before bedtime, sort of shortening that. So typically a lot of people will have,
00:40:39.220
you know, their dinner at seven and then, you know, a breakfast at seven. So they're going 12 hours
00:40:45.420
without protein coming in. So having another protein intake at like 10 before bed is something
00:40:53.400
that bodybuilders will often adopt. So typically we always try and tell people that if you're a normal,
00:41:01.380
healthy adult, try and get two meals at least, your breakfast and dinner, where the protein amount is
00:41:07.400
above 35 grams. If you're trying to gain muscle mass, you should have at least three meals and
00:41:14.320
possibly even four. So meal distribution takes on, again, a little different look depending on what
00:41:21.040
your personal goals are. I know intermittent fasting has become really popular. So people
00:41:25.940
might have a shortened eating window. So it might just be like a few hours. Is it possible to get all
00:41:30.360
your protein requirements in that, like maybe four hours that you have to eat?
00:41:35.760
Yeah. I don't like patterns as short as four hours. We know that the mechanisms for regulating
00:41:43.820
protein synthesis, once you turn them on, they're all active for at least five hours. So I think that
00:41:51.360
the next meal needs to be separated by at least more than five hours. You know, I like the concept of
00:42:00.360
I mean, the idea of time-restricted feeding is to reduce your just total eating. It's a calorie
00:42:08.360
control issue. I don't have a problem with that, but I think that the two meals should probably be at
00:42:16.300
least six hours apart. And again, you know, how do you get in 150 grams of protein, you know, six hours
00:42:23.500
apart. So 150, that means you're getting in 75 per meal. We know that your optimal use of protein for
00:42:32.820
muscle mass probably plateaus at somewhere around 60. So, you know, you talked about excesses. There's
00:42:40.520
probably a limit to how much protein you can use at a single meal. And we think the upper end of that
00:42:46.540
is probably 55 to 60 range. Okay. And so yeah, this would be below, like if you're a, you know,
00:42:54.100
an adult male or female, like that's not enough protein for like optimal, right? Yeah. So if you're
00:42:59.840
trying to do weight loss, if you're trying to restrict your calories, most of those people will
00:43:05.020
probably be targeting, you know, 100 to 120 grams of protein per day, distributing in that in two meals
00:43:12.340
of 55 grams is probably okay. But if you're trying to be a bodybuilder with 200 grams per day,
00:43:19.340
putting a hundred in each meal is a really bad idea. You need to distribute that across three or four
00:43:25.440
meals to optimize the effect. Speaking of weight management, is there any benefit of protein when
00:43:32.120
it comes to weight management? Yeah, we've done a lot of research on that. And so two ways to think
00:43:37.720
about it. One is we want enough protein to protect muscle. One of the problems of weight loss is what
00:43:45.220
we call yo-yo dieting. People will restrict their calories, lose 20, 30 pounds, and three months later
00:43:52.580
they gain it back. Well, every time you lose body weight quickly, up to half of the weight you're losing
00:44:00.620
is muscle, is lean body mass. Somewhere between 35 and 50% is going to be muscle mass. And so when
00:44:08.020
you lose it quickly and then regain it, yo-yo back up, what you gain back is just the fat and you've
00:44:15.560
lost muscle. So that makes it harder and harder to lose weight over time because you're losing your
00:44:20.960
lean body mass. So the first reason we want to use protein is to try and prevent muscle loss during
00:44:28.100
weight loss. We call it protein sparing. And we've shown that that's very effective. The other aspect is
00:44:35.980
when you're trying to really reduce calories, what should you reduce? And most of the research shows that
00:44:42.040
reducing carbohydrates is an important way to go. So when we add protein, we usually add it as a substitute
00:44:48.760
for carbs. So we'll add whatever, 50 more grams of protein to a diet and replace 50 grams of
00:44:57.380
carbohydrates. So we're going to higher protein, lower carbohydrate diets. When we do that, we know that we
00:45:04.040
reduce hunger, we increase satiety, we stimulate thermogenesis, the amount of heat you burn from meals. So you're
00:45:12.240
just wasting calories. And you also basically are sparing muscle protein loss. You're reducing, you're correcting
00:45:20.080
body composition. So there's a lot of reasons to increase protein for weight loss. We know that it's a highly,
00:45:26.880
probably the most effective way to correct body composition and lose weight.
00:45:32.320
So I've heard about this idea called the protein leverage hypothesis, and I'm intrigued by it. What do
00:45:37.800
you know about that? Can you walk us through that idea? Yeah. So Steve Simpson in Australia is a nutritional
00:45:44.200
anthropologist. He's actually a pretty good friend. He basically looked at the diet of humans,
00:45:52.520
but basically all animal species. And he realized that basically all animals eat toward a protein
00:46:00.320
target. And it's around 16, 17% of calories. And what his concept was, you know, we look back in time
00:46:10.320
and we realized that in the mid 1980s, all of a sudden we see this epidemic increase in obesity in the
00:46:18.180
United States. And we start wondering why. And one of the things that happened at that point is people
00:46:24.860
were so afraid of cholesterol and saturated fat, we developed what was called the food guide pyramid.
00:46:32.740
And the food guide pyramid said, eat a lot less animal products because that's the way you reduce
00:46:38.100
cholesterol and saturated fat and eat a lot more grain products. What that did was dilute out the nutrient
00:46:46.420
density of the diet. People ate 40% more calories from grains. We diluted the protein down and saw the
00:46:54.460
protein leverage hypothesis is, is that for adults to get to the protein target, they had to eat a lot
00:47:01.380
more calories. And that seems to be exactly what people did. They ended up eating 350 to 400 more
00:47:08.020
calories. Our protein intake stayed about the same, but we ate 400 calories more to get to it. And we think,
00:47:15.380
or that the theory is that that's the, was really the origins of obesity epidemic. And so we're now
00:47:22.620
seeing sort of a shift back to people are much more protein conscious. People are trying to reduce
00:47:27.820
the carbohydrate and we're seeing some people at least having much more success in controlling a body
00:47:34.060
weight. Yeah, it's really interesting and it makes sense. And I can see it with snack foods, right? A lot of
00:47:39.580
the snacks, they're high carb, low protein. So people's bodies are trying to hit their daily protein
00:47:45.440
target, you know, that what the body wants, but they just keep eating and eating in order to reach
00:47:50.540
it. And they eat through a lot more calories to get to the protein their body wants. Yeah. I mean,
00:47:56.700
the, the food industry has done a great job of developing foods that are very savory. The body sort of
00:48:04.580
recognizes them as that protein kind of taste and they're very addictive. And so to your point,
00:48:12.640
we're seeing a lot more snack foods, a lot more high carbohydrate grain based products in the diet,
00:48:20.520
and people are getting too many calories. Most of the data suggests that obesity is really associated
00:48:26.960
with snacking more than it is with meals. And, you know, I think that's true. I think portion size is
00:48:34.020
part of the issue, but I think the calories we consume outside of mealtime are a huge part of the
00:48:40.800
issue. And, you know, way to counter that, just be more conscious about the protein you consume,
00:48:45.740
be more deliberate about it. When we teach it for weight loss, we always teach people that
00:48:51.260
anytime you eat, you have to focus it on protein. You have to make a protein decision first. And so
00:48:58.300
you should never be eating anything that isn't focused on protein. And, you know, that it may be
00:49:05.380
that you're making a choice of eating some almonds for a snack or cheese or something, but you should
00:49:10.760
always be protein conscious. And likewise, when you're starting a meal, we teach people that the
00:49:17.100
first thing you eat at any meal needs to be the protein part. Your first bite needs to be a protein
00:49:22.280
bite. So when they bring out the bread or the chips or while you're waiting, you can't eat that
00:49:27.460
until the protein arrives because your body doesn't recognize carbs really for satiety very well.
00:49:33.760
The example I liked is, okay, we all go out for dinner and at the end of the dinner, and you're
00:49:39.160
basically full. If they bring out another steak, it's totally revolting. You're not going to eat it.
00:49:44.420
But if they bring out chocolate cake, you're perfectly happy to eat it. We just simply don't
00:49:49.240
register carbohydrates in the same way. Well, Donald, this has been a great conversation.
00:49:54.160
Where can people go to learn more about your work? So, you know, I'm on what used to be called
00:49:59.740
Twitter with at Don Lehman. So, you know, I try and provide some science there. I have a website
00:50:06.540
called MetabolicTransformation.com. And my colleague, Gabrielle Lyon and I have a book coming
00:50:14.820
out called Forever Strong that will come out October 17th, I believe, coming up. So new book,
00:50:21.920
Forever Strong, I think will be a great piece of information for the general public.
00:50:26.360
Fantastic. Well, Donald Lehman, thanks for your time. It's been a pleasure.
00:50:30.080
My guest today was Dr. Don Lehman. You can find more information about his work at his
00:50:34.640
website, MetabolicTransformation.com. Also check out our show notes at aom.is slash protein,
00:50:40.160
where you find links to resources, where you delve deeper into this topic.
00:50:49.920
Well, that wraps up another edition of the AOM podcast. Make sure to check out our website
00:50:54.120
at artofmanliness.com, where you find our podcast archives, as well as thousands of articles that
00:50:58.480
we've written over the years about pretty much anything you think of. And if you haven't done
00:51:01.840
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00:51:13.240
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00:51:16.320
reminding you to not listen to the AOM podcast, but put what you've heard into action.