Dr. Rhonda Patrick: What about people that are, you know, engaged in resistance training? So you are, you know, putting a stress on your muscle and, you know, obviously, there's going to probably increase the turnover as well. So how much do the demands in terms of protein requirements go up? Now, I know it probably depends a lot on what your goals are. Are your goals to be an elite bodybuilder or are your goals to stave off muscle atrophy? But it'd be nice to have, you know, what are some of the requirements for protein intake with people that are engaged in frequent resistance training, also some aerobic conditioning, not elite athletes, just regular people that are committed to health?

And also, you hear a lot in the bodybuilding community that you should just eat 1 gram of protein per pound, which is— 2.2 grams per kilogram body weight. I'd love to know what your thoughts are on that as well.

Dr. Luc van Loon: A lot of questions there. The first thing is protein synthesis is not the same as muscle protein accretion. So the building of muscle is not the same as reconditioning. When people like Stu Phillips, myself, we measure muscle protein synthesis. Now, the muscle protein synthesis goes up after exercise. When you do endurance type exercise, but also when you do resistance type exercise. The long-term adaptation, of course, is completely different. Look at the physique of a marathon runner and a bodybuilder.

That's hugely different, but they both have very high muscle protein synthesis after a training session. So the protein synthesis is a measure of to what extent does the muscle recondition to become more adapted to the type of exercise that you perform. Now we do see that if you ingest more proteins above 0.8 and towards, say, 1.6, 1 point— even some people suggest 1.8— that you get a more efficient reconditioning. Now, does the muscle need all that protein? No, because, for example, in the endurance athlete, the endurance athlete is not gaining weight. At least I hope not, because that wouldn't be good for him. But he is renewing that muscle much faster, and that requires fresh proteins coming in.

Now, what I said, the optimal requirements we don't know, but we do know is that at least for muscle mass gain, so for the resistance type guys that want to gain more muscle, that it tends to have greater gains in muscle mass and in muscle strength if you consume more protein than is what being advised. So if you go towards 1.2 or even 1.4 or 1.6. Going even higher than that, I think it's, it's, it's not relevant. It's not useful. It's not necessary. It's also a bit of a self-fulfilling prophecy, because if your body adapts to more protein, it will need more protein. So that is, that is just natural in the situation. Your body adapts to its use, so you can actually maintain your, your body mass on a low protein intake and on a high protein intake.

And there must be a sweet spot somewhere. And I think most people are spending too much time thinking about what the sweet spot is, because the 0.8, hardly any— whether we're talking about young or old, there's hardly anybody consuming 0.8. If you're a healthy older or a healthy young sedentary person, you easily consume between 1 and 1.3 grams of protein per kilogram body mass per day. I mean, if 10 to 15 energy percent of your diet is protein, you easily get to 1 to 1.3. And that's also people that don't take supplements or just don't think about the nutrition. If we see elderly or older people in our test, between 1 and 1.3. Now, if you're an athlete and you're exercising, you eat more simply because you need to be in energy balance. 10 to 15 energy percent comes from protein.

So if you're physically active, you automatically already consume 1.5, 1.6, 1.7 grams of protein. Do the math. Think about Tour de France cyclists. They're not big guys. They actually expend about 25 megajoules of energy on a daily basis in the Tour de France. If only 10% of that comes from protein, they already consume well above 2. It's not what they need, but people are too worried about the total amount of protein. They're already getting enough protein if they stay in energy balance. It becomes more important when you actually can't eat a lot of food. Then the puzzle becomes more difficult.

Dr. Rhonda Patrick: What about people that are not in energy balance? Let's say there are people that are undergoing energy restriction to change body composition.

Do protein requirements— is it beneficial to change protein requirements and perhaps increase them in that specific condition?

Dr. Luc van Loon: What we typically see when people try to lose weight, for example, so if they are on a hypocaloric diet, is that they lose— that they— if they eat less and they try to maintain their absolute amount of protein, the decline in muscle mass is less. So maintenance of your absolute daily protein intake is more important. And that's exactly what relates what I said before. Your body adapts to a certain amount of protein, and if you suddenly reduce the protein intake, that might go at the expense of muscle. So also, when people go into the hospital and they're not exercising, they're also eating less because of pain and stuff like that.

We try to optimize or maintain at least the total amount of protein that they were consuming before they went into the hospital. That will attenuate, or at least attenuate a little bit, the muscle loss that they have. So maintenance of your normal protein intake is an essential thing.

Dr. Rhonda Patrick: How does resistance training and training in general change the way the muscle responds to amino acids?

Dr. Luc van Loon: Exercise increases muscle protein synthesis, also increases muscle protein breakdown, but it increases muscle synthesis to a greater extent than it increases muscle breakdown. So net balance becomes better. That's without food intake.

If you throw protein on top of that, then breakdown is inhibited to some extent and protein synthesis is further increased, allowing you to adapt and to recondition the muscle to what you're aiming for. And that could be like more mitochondrial proteins when you're an endurance athlete. Or myofibrillar proteins when you're becoming a more resistant type athlete.

Dr. Rhonda Patrick: Okay, so is that kind of why you were saying when you, let's say you're training and then you increase your protein intake to 1.6 to 1.8, let's say you're going higher and you're doing that for a while and your body adapts to that amount, then if you take that away and you're still doing the training, then does it adapt quickly as well or will you start to lose muscle mass?

Dr. Luc van Loon: We don't know, but I would predict, and let's do the extreme. There's anecdotal reports of people that have a very high protein intake diet, and then you tell them that they don't need that amount of protein, and then they do an experiment, and they basically say, okay, you know what? I'm going back to 1.5, and I used to be eating so much supplements. I was sitting at almost three grams per kilogram body mass, and I bring it back down to 1.5. I'm losing muscle, so I'm not doing it anymore. I'm not sure what would happen if they actually kept it there for a while, because it's homeostasis. Your body adapts.

So probably if you're consuming more than 3 grams of protein per kilogram body mass per day, the turnover of other tissue and/or the oxidation of the protein will probably be at a higher level. So you can't basically get a new homeostasis within like 2 or 3 days. That requires studies that look at changes over time. I mean, like I said, I mean, we now tell everybody that 0.66 or 0.8 is the minimal requirement. I assume that that's people that eat much less protein, but they still stay in balance. If you go to a third world country of people that are not consuming enough food, they adapt. And so it's also on the other side. I think you can adapt to a high protein intake even if you don't need it. Is it a healthy thing? We don't know. Do you increase the turnover rates of other tissues?

We don't know. And if the turnover is increased, is that a good thing? Is that a bad thing?

Dr. Rhonda Patrick: When you say they adapt, like for example with respect to the extreme low protein diet level, I mean, they adapt, but they're not building muscle. Is that correct?

Dr. Luc van Loon: They're not building muscle, but they're maintaining in a nitrogen balance.

Dr. Rhonda Patrick: Until they get older and then it's harder to stay in the balance if you're not getting enough protein?

Dr. Luc van Loon: If they're losing muscle, they're not in balance. But again, then we're talking about muscle. Yeah. And with the nitrogen balance, you measure on a whole body level. Okay. And that's one of the reasons why you can't translate the protein requirements directly to what is happening in the muscle. The muscle just enjoys when it gets more protein.

It can do much more. I mean, if you would actually increase your liver or your organs by a higher protein intake, we would probably have a health issue.

Dr. Rhonda Patrick: Well, what about— you've done some research on anabolic resistance, and maybe you can explain to people what anabolic resistance is and how that is relevant in terms of protein intake for older adults.

Dr. Luc van Loon: Yeah. If you give young healthy people about 20 grams of a high-quality protein, you see a maximal stimulation of muscle protein synthesis. Giving 40 grams did not result in a greater muscle protein synthesis. We'll talk about the 100 grams later on, probably. But so, in the next 4 to 6 hours after a meal, 20 grams of protein maximizes muscle protein synthesis.

Now, if you do that the same, if you do that in older people, and you give them the same 20 grams of protein, they show a lesser stimulation of muscle protein synthesis, and they do not reach that same level, and certainly not the maximum level. So that's what they now call anabolic resistance. We see that the same amount of protein does not lead to the same increase in muscle protein synthesis that you see in young people. That is now defined. I mean, Mike Rennie's group was the first to define that as anabolic resistance. But the question is, is what, what is causing anabolic resistance? Is that because of the age? But of course, if you compare young and older groups, it's not only about age.

If you compare a young and an older person, it's the age, it's the lifestyle, it's the habitual food intake, habitual protein intake, it's the co-medication, the comorbidities that they have. So you're comparing a lot more. Now, one of the strongest things that increases the sensitivity to food intake is physical activity. Now, if you provide— if you give an older person an exercise session before food intake, their response is almost completely normal. So much of the responsiveness, the anabolic resistance, can be overcome by physical activity. So my question is, to what extent is anabolic resistance, not for the greatest amount, simply secondary to a lower physical activity level?

Dr. Rhonda Patrick: Okay, so if I'm understanding correctly, most of the anabolic resistance with older age is attenuated with physical activity, resistance training, just being physically active?

Dr. Luc van Loon: Yep.

Dr. Rhonda Patrick: Well, that's pretty incredible because you're right, a lot of people do, as they get older, they do become less physically active. Certainly people that aren't necessarily focused on their exercise, right? I mean, just, normal people that are kind of more active perhaps when they're in their job and then they retire and then they're not as active.

Dr. Luc van Loon: Yeah. I mean, that's probably the biggest, I think, for the general population, the biggest problem is when they then retire and then they're just sitting at home and then no longer physically active.

So knowing that anabolic resistance can be overcome by physical activity is mostly overcome is, I think, extremely important for public health.

Dr. Rhonda Patrick: Before we wrap up, before we dive into some of that a little bit more, I wanted to— you mentioned something about being overweight and obese with respect to protein requirements, because in the United States many people are overweight and obese, and people like listening to this podcast might look at that number, 0.8 grams per kilogram body weight, and directly translate that to their weight, which could be quite high.

So how does a person who is overweight and obese? Perhaps it's not as important because they're probably, like you said, they're consuming enough food so they don't have to worry about it, but there are anal people that want to think about calculations no matter what. How does that person approach how much protein they should be taking in when they are obese or overweight?

Dr. Luc van Loon: If you would actually modulate your protein requirements towards the tissues that require the protein, then it would be better to basically base it on fat-free mass. Because of course a lot of the fat mass is not that metabolically active. It's most of it is fat depot. So turnover of protein is relatively small compared to the organs and the muscle.

So if you have the fat-free mass or the organ mass and the muscle, and actually say like, hey, 0.8 for an 80-kilogram weighing man, then also related to the 0.8 based on those 80 kilograms and not on the 20 or 40 excess fat depots that you have on you.

Dr. Rhonda Patrick: Most people aren't going and measuring their fat-free mass, but that is something that can be done. People can go get— would you say doing a DEXA scan would be something that would be more—

Dr. Luc van Loon: Yeah. There are so many options. I mean, you can make a body volume scan, you can— there's nice apps nowadays. We heard it yesterday in the conference also, but you can also do a DEXA scan, body circumference measurements, or— but most people know how much overweight they are. Come on.

I mean, if you know, if you're 180, you know that somewhere between 80 and— and for male, you should be somewhere between 80 and 90 kilograms. If you're 110, it's probably you have about 20 kilograms excess. And now taking myself as an example, you know how much overweight you are. Most people do know that. Yeah.