Episode #388: Muscle Imbalances, Red Meat Risk, and the Science of Body Fat Set Points

0:01 [SPEAKER_01]: Welcome back to the Barbell Medicine podcast. [SPEAKER_01]: I'm Dr. Jordan Faganbaum. [SPEAKER_01]: This is a special preview of our Barbell Medicine plus direct line. [SPEAKER_01]: It's our monthly exclusive. [SPEAKER_01]: Subscribe or only ask us anything where we move past the basics and dive into the technical nuance that defines the Barbell Medicine plus experience.

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0:38 [SPEAKER_01]: To start today's podcast, we are going to begin by challenging a common belief in the fitness industry, the idea that muscle imbalances are a reliable predictor of pain and injury risk. [SPEAKER_01]: Here we explain why asymmetry is often a functional adaptation, rather than a clinical problem, a feature, not a bug, and how a better understanding of the normal versus the pathological may change your approach.

1:00 [SPEAKER_01]: Let's get into it. [SPEAKER_01]: do muscle imbalances reliably predict pain and or injury risk, and how should coaches manage clients who dogmaticly believe in these models, a lot of stuff here, yeah, we'll go through a piecemeal, starting first with just the basic premise, like do muscle imbalances reliably predict pain and or injury risk.

1:26 [SPEAKER_01]: And I think one way to look at this is kind of thinking about [SPEAKER_01]: So how would you differentiate between something that is, quote, normal and something that is pathological in so far as it either is representative of an injury or a causing pain, something like that verse, a adaptation that we see in response to either exercise or in some cases even disuse bright lack of lack of exercise?

1:52 [SPEAKER_01]: And when we think about this or at least when I think about this through the lens of asymmetry, [SPEAKER_01]: I don't think that human bodies are naturally symmetrical, you know, you think about everything from like the muscle size from, you know, agonist antagonist pairings and even the muscular strength, like quadriceps are stronger than hamstrings, calves are stronger than your tibialis anterior and the muscles on the front of your lower limb, your triceps are stronger than your biceps and so they're not symmetrical, like on either side of a joint, for example.

2:23 [SPEAKER_01]: When people say, oh, uh, there's an asymmetry, is it side to side? [SPEAKER_01]: What they're talking about is it really agonist antagonist pairing, um, and, you know, the literature is littered with the examples of athletes across the, uh, compendium, you know, novice to elite levels that have massive, quote, imbalances and not only muscle size, but also anatomical features that you could see on, like x-ray, uh, for example, on their dominant side, you know, tennis players, their dominant [SPEAKER_01]: If you look at rotational sport athletes, I'm thinking about like not only cricket players, but also like roars.

3:01 [SPEAKER_01]: If you look at their vertebral features on one side, you look at vertebral features and weightlifters. [SPEAKER_01]: They have thick and vertebral end plates and thicker cruciate ligaments in the knees. [SPEAKER_01]: These are all quote abnormal if you were to just see them on imaging. [SPEAKER_01]: And they may not be the same side to side, but their features not bugs.

3:20 [SPEAKER_01]: And so I think if that's your base understanding of like should things be symmetrical front to back or side to side, generally not it's not not consistent like the human experience, but people can have pain, despite all of this right, just like people can be asymptomatic, despite being quote asymmetrical, so I think if I were really going to simply kind of answer this very simply.

3:46 [SPEAKER_01]: I don't care about asymmetry, that much, whether it's side to side or like an agonist antagonist pairing. [SPEAKER_01]: In most cases, what I do start caring is either post-operatively or post-traumatic injury. [SPEAKER_01]: I'm thinking about somebody who had an ACL repair or somebody who tore a hamstring, something like that, and then side to side, there's a huge difference in hamstring strength, their lower extremity strength, otherwise.

4:12 [SPEAKER_01]: We probably do need to do some specific work to shore that up, but outside of that sort of setting either post-op or post-traumatic injury, rupture, tear, something like that. [SPEAKER_01]: I just don't care. [SPEAKER_01]: I don't know. [SPEAKER_01]: What do you think about that? [SPEAKER_00]: Based on what you have described, I'm imagining kind of three different trajectories that you can imagine people falling on and the amount to which their asymmetry presumably in many of these situations, it's side-to-side.

4:37 [SPEAKER_00]: How much it matters, depends on which of these trajectories you fall. [SPEAKER_00]: One is it is a inherent asymmetry to you, like in general, you know, one side might be a bit stronger or formed in a different way compared with the other and it's always been that way. [SPEAKER_00]: In those situations when you choose to engage in a particular activity or sport.

4:55 [SPEAKER_00]: starting out with that basic asymmetry. [SPEAKER_00]: It will either tend to maybe improve a little bit, depending on the demands of the task, or you will adapt to be able to perform the task with your asymmetry in place. [SPEAKER_00]: So it is a long-standing, pre-existing sort of thing.

5:09 [SPEAKER_00]: You will either adapt one way or another, and it generally is not going to be a problematic thing for most people. [SPEAKER_00]: the other situation that you described is maybe some of those kind of single-sided sport athletes maybe they were actually started out more symmetrical before they engaged in the sport and then the more of the sport they did be at baseball pitching they tend to usually throw with one arm or tennis players or [SPEAKER_00]: You know, other racket sports or roars like our buddy, Dr. Biles, who only spent his life turning in one side of a boat, and he has thoracic rotation much more in one way than the other.

5:42 [SPEAKER_00]: That is an acquired asymmetry, meaning over a longer period of time that kind of coincided with the adaptation to the sport. [SPEAKER_00]: That also tends to not be super problematic. [SPEAKER_00]: The last trajectory where symmetry and asymmetry tends to be more of an important consideration is one where it is an acquired asymmetry, but it is much more abruptly acquired.

6:08 [SPEAKER_00]: It is not one that was longstanding before you ever entered the sport. [SPEAKER_00]: Nor was it one that you gradually acquired as you participated in the sport, but rather it was a more abrupt acquisition, meaning you suddenly had surgery, and now you're... [SPEAKER_00]: Now your asymmetric side to side or you had a traumatic injury and now your asymmetric side to side or you had a fracture or a neurological injury and now you have you know differences in limb lengths or movement patterns or something else that [SPEAKER_00]: You have not had years of existing with and exposure to and training with to adapt to or to develop as a natural course of your adaptation.

6:50 [SPEAKER_00]: So that's kind of the way that I'm framing this is like, maybe there's something to this idea in terms of how quickly it was acquired. [SPEAKER_00]: And acutely acquired asymmetry may have more of a risk of like too much, too soon, and then subsequent pain. [SPEAKER_00]: Whereas one that was either long-standing pre-existing will generally be much less likely to be problematic, and one that you acquire through the course of your training and performance is also unlikely to be problematic.

7:19 [SPEAKER_00]: And so we do have some material on this. [SPEAKER_00]: If you're interested, for example, in, I think Derrick's articles titled Something to the Effect of Like Wind Symmetry Matters on our side. [SPEAKER_00]: And it really is focused around, for example, his, you know, pet topic of ACL and Postoperative Rehab, [SPEAKER_00]: But that's kind of the way that I think both of us are thinking about this, to where if somebody is experiencing some pain, for example, or an injury, and there was not anything else abrupt or acute about any of these changes, but we simply incidentally find some side-to-side differences that have probably been there for a long time.

7:54 [SPEAKER_00]: or all along, or had probably were even there before they even started lifting or participating in the activity. [SPEAKER_00]: We're less likely to put a ton of attention on that, compared with if they never had any issues, never had any pain. [SPEAKER_00]: And then, oh, I got in this car crash and fractured my femur.

8:10 [SPEAKER_00]: And after surgery, my left leg is now two inches shorter than my right because of the way the surgery was done, which I have questions about that so that surgery. [SPEAKER_00]: And now I'm experienced, well, it's like, yeah, your mechanics are like much more acutely different. [SPEAKER_00]: And it is much more your threshold or your tolerance, the too much too soon, as much easier to hit when you have not been like long-term exposed and adapted to that asymmetry in the same way.

8:32 [SPEAKER_00]: So hopefully that makes sense. [SPEAKER_01]: Yeah. [SPEAKER_01]: Yeah. [SPEAKER_01]: So as far as how to do deal with this, what if you're dealing with somebody who is firmly entrenched in this like asymmetry, you know, debate. [SPEAKER_01]: And they really think that if someone is asymmetrical, either side to side or between, you know, various strengths, strengths of muscle groups, that's what's causing pain and injury risk.

8:55 [SPEAKER_01]: I think you should be respectful, generally speaking, good advice, but also to ask for the evidence to support that. [SPEAKER_01]: And you can weigh the veracity and how that evidence was collected and generated and see if that makes sense to you. [SPEAKER_01]: People are going to talk about upper cross syndrome, lower cross syndrome, much agenda stuff, and the evidence on that is just made up.

9:17 [SPEAKER_01]: shenanigans. [SPEAKER_01]: You can observe things and then not necessarily prove that they have caused the end effect. [SPEAKER_01]: We see that all the time. [SPEAKER_01]: So that's for dealing with experts, just ask for evidence, roll that around in your head and generally speaking, it's nice to at least know where other people are coming from so you can kind of better appreciate their perspective.

9:39 [SPEAKER_01]: And further some people that you might come in contact with professionally in the future, [SPEAKER_01]: as far as clients go, this it goes all back to like communication styles. [SPEAKER_01]: I think validating how people feel initially or off the bat sort of helps build that rapport. [SPEAKER_01]: So, you know, you can say things like it's very common to feel tight, weak, in a particular area, especially when you're in pain.

10:02 [SPEAKER_01]: However, we know that from looking at thousands of people that these differences are actually a normal part of being human, you know. [SPEAKER_01]: and you're just more sensitive right now. [SPEAKER_01]: So that's some reassurance there as well. [SPEAKER_01]: You're not out of alignment.

10:12 [SPEAKER_01]: Right now you're just sensitive, things like that. [SPEAKER_01]: You can also mention instead of worrying that your left side matches your right side perfectly. [SPEAKER_01]: Let's focus on making both sides stronger. [SPEAKER_01]: And that's typically the approach I like to use where the squeaky wheel so to speak is kind of get the grease.

10:28 [SPEAKER_01]: You know, if your right leg is not as strong as your left leg and you're doing split squats, for example, the right leg is going to get a different training stimulus than the left leg. [SPEAKER_01]: long standing sort of asymmetries, whereas the surgical stuff, you'll need some different loading, doesn't mean the exercise is something you can't use.

10:46 [SPEAKER_01]: And most importantly, sort of as not to alienate the person who's in front of you is don't argue with them. [SPEAKER_01]: pretty interesting, right? [SPEAKER_01]: Okay, while understanding the mechanics of the body and how it adapts is important for coaching, knowledge of what's going on under the hood or inside the body is important for long-term health outcomes.

11:11 [SPEAKER_01]: In the next segment, we're shifting away from the way our muscles look and work to the way our blood chemistry responds to nutrition and lifestyle. [SPEAKER_01]: In this next segment, we're looking at the intersection of saturated fat, red meat, and the often misunderstood lean mass, hyper-responder phenotype.

11:26 [SPEAKER_01]: Let's take a look at the evidence and go beyond the trending headlines. [SPEAKER_01]: Next question, is limiting red meat and saturated fat necessary for someone who has otherwise optimal health metrics in a high fiber, high activity lifestyle? [SPEAKER_01]: This is an interesting question, because I think the crux of the question and the meat of the question, if you will, is look just how independently risky is red meat or are red meat in saturated fat.

12:01 [SPEAKER_01]: And to that, I would say depends how much you're eating of it. [SPEAKER_01]: And what does the rest of the diet look like? [SPEAKER_01]: I mean, it depends, which is not a satisfying answer. [SPEAKER_01]: So maybe let's back up a second. [SPEAKER_01]: I think when you compare these different dietary patterns, things that are rich in red meat and higher and saturated fat to other dietary patterns, particularly those that are plant-based, and you just look at observational trials, studies, so where they look at different groups of people, eating these ways over a long periods of time, [SPEAKER_01]: you're going to see almost universally plant-based diets just win.

12:34 [SPEAKER_01]: They just win. [SPEAKER_01]: And so, you know, vegetarians, vegans, people who like that dietary pattern, say, see, look at the data. [SPEAKER_01]: And on the one hand, they're correct, but not for the right reasons. [SPEAKER_01]: Because a lot of that is is picking up what we call like a healthy user bias.

12:49 [SPEAKER_01]: Generally speaking, people eat more plant-based diets. [SPEAKER_01]: Not only, they just tend to be fundamentally different from those who eat a diet that's [SPEAKER_01]: they tend to exercise more, they tend to eat more dietary fiber, obviously, but they also tend to be more health-conscious generally speaking.

13:05 [SPEAKER_01]: Go to the doctor's office, eating a plant-based diet also tends to cost more. [SPEAKER_01]: So, socioeconomic status differences, you can keep going down the line. [SPEAKER_01]: There's just fundamental differences between the two avatars that we're comparing here at the level of observational data.

13:20 [SPEAKER_01]: So most of the health differences that you're seeing at those types of studies are just because the dietary pattern are so fundamentally different that that's what they're picking up and likely from a lot of other things that aren't just related to the dietary pattern as well. [SPEAKER_01]: I think this question is more like, well, yeah, so let's eliminate all of that.

13:42 [SPEAKER_01]: Let's say in this particular case, the person eating red meat and a diet that's high in saturated fat, but everything else is optimized. [SPEAKER_01]: Well, that doesn't absolve you from the risk of elevated, you know, anthropogenic load, you know, uh, so LDL cholesterol particles, apoliproportine B, uh, containing particles.

14:05 [SPEAKER_01]: And I think we just have really good evidence suggesting that if those levels are elevated, making changes to lower them with generally reduced risk of heart disease. [SPEAKER_01]: And so, [SPEAKER_01]: I mean, I think that's the most simple answer to this. [SPEAKER_01]: It's like, yeah, having everything else optimized, you're certainly in a better place than if they weren't, but you could probably get a little bit more optimized for some individuals if they're apolipoprotein B.

14:31 [SPEAKER_01]: Test was high, for example, or if they had other additional risk factors or maybe not as modifiable, like elevated lipoprotein little A, family history of heart disease where you'd want to be more aggressive potentially. [SPEAKER_01]: I don't know, is that how you think about this? [SPEAKER_00]: In a sense, I think that the way this question is framed is limiting it to quote, necessary.

14:50 [SPEAKER_00]: And that idea of, is it necessary? [SPEAKER_00]: Really is something that requires the context of what are the person's goals? [SPEAKER_00]: Are they one of these folks who you're describing is wanting to optimize everything? [SPEAKER_00]: To which I have several other questions, for example, like, do you drink any amount of alcohol?

15:06 [SPEAKER_00]: Yeah, because like, if all of this other stuff is perfect, and that's your last question, it's like, well, some of these other behaviors still might confer greater greater risk. [SPEAKER_00]: The other way that I'm thinking about this is your right that by and large, the overwhelming body of evidence would suggest that.

15:22 [SPEAKER_00]: continuing to substitute, you know, the red meets and set an animal derived saturated fats for plant derived protein sources and things like that is consistently likely to confer health improvements or benefits compared with going in the other direction. [SPEAKER_00]: There is, if it was just, um, all correlational, it was all just messy, then you would see [SPEAKER_00]: at least some weighting of evidence also going in the other direction among these healthy people.

15:48 [SPEAKER_00]: But pretty consistently we see in various lines of evidence that substituting out those animal derived saturated fats and red beans for plant derived protein sources, pretty consistent signal in the direction of health benefit. [SPEAKER_00]: And so I think that the more of that that somebody is willing to do, [SPEAKER_00]: the more benefit they are likely to derive, although as with most other things here, that benefit has diminishing returns.

16:13 [SPEAKER_00]: So if somebody is eating a rib eye a day, then substituting one of those out for something else is likely to give them a pretty substantial risk reduction. [SPEAKER_00]: And then for each one from then on, although it down to one a week or half a serving a week or a quarter serving a week or an eighth of a serving week, [SPEAKER_00]: you know, the incremental risk reduction that they get at those levels is less and less and less.

16:37 [SPEAKER_00]: And so I think it is probably uncontroversial between either of us and for many folks who are in our orbit to say that like yeah, fatty red beats should not form a predominant should not be a predominant element in your habitual dietary pattern. [SPEAKER_00]: If somebody is choosing to consume it on an occasional basis and they do not have any evidence of untoward health consequences like elevated blood lipids or other factors like that, then are they accepting some degree of risk compared with if they chose to substitute that out for salmon, for example.

17:10 [SPEAKER_00]: I would say, yes, it would probably be better if they were to substitute it for say, how much better it might not be enough to make them motivated to do that just because of their preferences or their cultural, you know, food habits and things like that in the same way that when we talk about is a cholesterol lowering medicine likely to lower your risk.

17:29 [SPEAKER_00]: Yes, that is actually the case for 100% of the population, essentially, but the actual amount of risk reduction is not equivalent for everyone across the board. [SPEAKER_00]: It gives you a say 25 is to 30% relative risk reduction. [SPEAKER_00]: Relative risk reduction means it depends on where you're starting risk is, so if you're starting risk is very high, you enjoy more benefit or you're more likely to benefit.

17:53 [SPEAKER_00]: If you're starting risk is super low, you're less likely to benefit. [SPEAKER_00]: And so if you this kind of similarly, it might be the case that all your levers are maximally pulled in your health. [SPEAKER_00]: And you're like, hey, can I just have like maybe a modest portion of a steak once a week or something like that?

18:10 [SPEAKER_00]: And I would say, you know, well, what are your goals here? [SPEAKER_00]: And if you want to have, I want to live, I want to, I want to, I want to Brian Johnson this thing. [SPEAKER_00]: I want to live forever, whatever. [SPEAKER_00]: I'm like a aggressive optimizer. [SPEAKER_00]: I'd say, [SPEAKER_00]: Yeah, I'd probably substitute that for something else, but if you're like, look, I'm doing as much as I'm willing to do to improve my health and this brings me great joy and whatever, you know, trivial amount of risk it brings.

18:32 [SPEAKER_00]: I'm not concerned with because. [SPEAKER_00]: You know, one other day of the week, I enjoy a glass of wine or something like that and it's like, okay, well, you have determined the amount of risk that you're willing to accept. [SPEAKER_00]: If you really want to like maximally pull every lever, you want to live, you know, that type of life, then yeah, probably would look at substituting that out for something else.

18:52 [SPEAKER_01]: Yeah, yeah, there was a interesting paper that came out a few years ago where basically to experts arguing on either side of this, like, should we reduce the saturated fat target for Americans in the food guidelines, and, you know, currently it's a, as far as your daily calories go less than 10 percent of your daily calories from saturated fat.

19:14 [SPEAKER_01]: and on the pro side argued yeah we should keep that in there maybe even consider lowering it it's like we'll look the people consumed less saturated fat particularly from red meats most people are going to have a favorable response in the blood lipid level and that's going to favorably impact their you know relative risk of cardiovascular disease [SPEAKER_01]: And on the other side, arguing against, they were like, look, the average intake, as far as percentage of daily calories for saturated fat, it's 11%, so like, does it even need to be in there?

19:42 [SPEAKER_01]: Like, who cares? [SPEAKER_01]: No one reads the guidelines anyway. [SPEAKER_01]: Yeah, we've got it. [SPEAKER_01]: And so yeah, there's two sides to that argument. [SPEAKER_01]: I think to maybe clear this up and really summarize this, we can talk about this lean mass hyper-responder phenotype that's going around the interwebs.

19:58 [SPEAKER_01]: So this is a person who sees a significant rise in cholesterol, their blood lipids, following the adoption of like a ketogenic or low carbohydrate diet. [SPEAKER_01]: So the criteria that the people within that orbit that they say to be a lean mass hypersmonder, you don't actually have to be lean.

20:17 [SPEAKER_01]: But your LDL has to go up in response to a low carbohydrate diet to greater than 200 milligrams per desoliter in associate with an HDL cholesterol that's greater than 80 and triglycerides that are less than 70. [SPEAKER_01]: So effectively what this is saying is like your LDL is elevated.

20:33 [SPEAKER_01]: That's the only thing that's weird about your standard lipid panel. [SPEAKER_01]: Okay, and they're saying, look, if this is you and you're in a low carbohydrate diet, you're in no-elope, no increase risk of heart disease because you're triglycerides are low, your HDL is high. [SPEAKER_01]: This is just an aberrant sort of relationship due to the nature of you following a low carbohydrate diet.

20:56 [SPEAKER_01]: Unfortunately, evidence on this is not very supportive of that hypothesis. [SPEAKER_01]: Like, you would have to just say, like, look, the LDL being increased, which we know carries April, lipoprotein B, and that is a good representative test of your atherogenic load, which we know is like this time volume issue.

21:12 [SPEAKER_01]: The higher it's elevated, the longer it's elevated for the higher the risk. [SPEAKER_01]: You just have to say, now we're ignoring that in a specific case. [SPEAKER_01]: Austin, how do you, what do you think about that? [SPEAKER_00]: I think it's a bold claim, and I'm not opposed to people making bold claims if they as you often say bring receipts and to date, they lack hard human outcome-based receipts.

21:32 [SPEAKER_00]: A lot of this is mechanistic kind of hypothesizing. [SPEAKER_00]: They attempted to do this study that was popularized and went around the internet recently, called the Keto CTA study that had a fair amount of problems with it. [SPEAKER_00]: let lead to some egg on their face, I think, based on the speed of plaque development in people who fit this phenotype.

21:52 [SPEAKER_00]: And so, yeah, this is an area where I have actually found it pretty straightforward to not get terribly worked up about it. [SPEAKER_00]: mainly because of the types of people who end up in this space. [SPEAKER_00]: The people who end up in that orbit that you describe and subscribing to that view, they are people who generally are going to be pretty skeptical of a lot of medical advice, pretty contrarian in general.

22:22 [SPEAKER_00]: They are often heavy motivated reasoners in terms of [SPEAKER_00]: trying to find ways to think about things that justifies their existing dietary patterns. [SPEAKER_00]: And cool, like, you know, it's your risk, it's not mine. [SPEAKER_00]: I come back to this often of like, here's my advice, you're free to take my advice, or if you want to go someplace else for someone else's advice.

22:41 [SPEAKER_00]: Like, good luck. [SPEAKER_00]: Hope it works out for you. [SPEAKER_00]: You know, most people in that situation, [SPEAKER_00]: may well do perfectly fine because you have a lot of other health things going in your favorite. [SPEAKER_00]: You don't have the atherogenic dyslipidemia phenotype where you have high LDL, high triglycerides, and very low HDL.

22:59 [SPEAKER_00]: That is no doubt a higher risk type, right? [SPEAKER_00]: That is the worst type. [SPEAKER_00]: That is the one associated with insulin resistance diabetes, things like that. [SPEAKER_00]: The claim they are making is not that phenotype, but if you have high LDL and the others, HDL are high in triglycerides are low rather than the opposite.

23:15 [SPEAKER_00]: is that completely risk-free? [SPEAKER_00]: Or is it just lower risk than the worst case phenotype? [SPEAKER_00]: And that's where I would be interested to see data. [SPEAKER_00]: If you can show that people who have this lipid phenotype are essentially equivalent risk to somebody who has the same phenotype but just with low LDL, that would be actually kind of groundbreaking evidence because it would [SPEAKER_00]: be in opposition to, you know, the vast majority of lipid data for the past century.

23:41 [SPEAKER_00]: So that's what I mean. [SPEAKER_00]: Big claim needs some big evidence and until that is lack and until we have that big evidence, you know, I'm not going to get to work up about it. [SPEAKER_00]: You can do what you want with your diet, your lifestyle. [SPEAKER_00]: Good luck. [SPEAKER_01]: Yeah, big if true.

23:54 [SPEAKER_01]: Yeah. [SPEAKER_01]: I definitely think you had predicted that a person which is isolated elevated LDL would be lower risk, but to say that it's no risk. [SPEAKER_01]: Exactly. [SPEAKER_01]: It's equivalent, it's saying like, look, a person with excess body fat and they're very fit and they're carrying a lot of muscle.

24:08 [SPEAKER_01]: They're at no increased risk of medical problems from excess body fat and you're like, well, that's not. [SPEAKER_01]: true. [SPEAKER_01]: They're a less risk. [SPEAKER_01]: You know, if they have less muscle mass, you know, for example, or less fitness, but it doesn't absolve them of the risk of this well-characterized risk factor, same thing with blood pressure.

24:25 [SPEAKER_01]: So you just keep going down the line. [SPEAKER_01]: You would prefer everything to be optimized. [SPEAKER_01]: If you were an optimizer. [SPEAKER_01]: And so I think to just tie this back in, it's like, [SPEAKER_01]: Should you limit red meat and saturated fat? [SPEAKER_01]: It really just depends on how much of it you're eating, how that is affecting all of your risk factors and your personal goals and risk sort of tolerance.

24:48 [SPEAKER_01]: I think both of us would say that we're both tolerant of some risk related to red meat because we enjoy it. [SPEAKER_01]: But if we were trying to maximize longevity, we would shift even further towards more plant a more plant-based dietary pattern. [SPEAKER_00]: Yeah, that's true, and I think that reflects even the trajectory of my own dietary pattern over the past like decade or so.

25:08 [SPEAKER_00]: It has been progressively less of that over time and much more heavily in the other direction at this point. [SPEAKER_00]: So yeah. [SPEAKER_01]: Okay, hopefully you found that as interesting as we did, let's move on to the next segment. [SPEAKER_01]: Now analyzing blood lipids can give us a snapshot of a current cardiovascular risk, but to understand the effects of body composition on long-term health, we've got to look at how the body regulates its own weight and energy stores over decades.

25:40 [SPEAKER_01]: That brings us to the dual intervention point model. [SPEAKER_01]: In this segment, which is admittedly my favorite, we break down the evolutionary biology of why the body defends certain levels of fat and weight, moving past the simplified view of energy balance and into the complex regulatory systems of the human body.

26:00 [SPEAKER_01]: In the dual intervention point model, does the body defend absolute scale weight or body fat percentage? [SPEAKER_01]: So if you're not familiar with this dual intervention point model, this was suggested via Dr. Speekman. [SPEAKER_01]: He's one of the pillars in the research community regarding obesity, energy expenditure, also now just recently did a study on GLP ones.

26:25 [SPEAKER_01]: Condersite sort of stimulation at the level of the joint space, but this particular model is basically suggesting that human body weight and body fatness. [SPEAKER_01]: He puts both of those things together. [SPEAKER_01]: Are regulated between two set points, one on the low end and one on the high end.

26:44 [SPEAKER_01]: On the low end, we're defending against sort of a frailty starvation, alt death. [SPEAKER_01]: Effectively, [SPEAKER_01]: someone lost too much weight, too much body fat, their fitness for reproducing would be compromised. [SPEAKER_01]: And on the high end, we're protecting against predation, being eaten by an animal.

27:05 [SPEAKER_01]: For example, because we can't move, can't avoid that. [SPEAKER_01]: Ultimately, again, reducing fitness to reproduce. [SPEAKER_01]: All right. [SPEAKER_01]: And he extends that theory with some speculation and admittedly, he caveats that appropriately is like, look, there's no more predation sort of pressure anymore.

27:23 [SPEAKER_01]: Now, again, this is mostly speculative, but in this model, if somebody were approaching the lower threshold, their body would push back and reduce energy expenditure and increase energy intake to defend against going any lower. [SPEAKER_01]: And at the upper end, the body would do the opposite.

27:42 [SPEAKER_01]: It would increase energy expenditure and lower energy intake to prevent the person from gaining any more weight and any more body fat. [SPEAKER_01]: Okay. [SPEAKER_01]: The idea is that over time, as our environment has changed, we've had a genetic drift upwards of both of these points.

27:55 [SPEAKER_01]: That's why we're getting fatter as a globally for the most part and that explains our response to the environment because it has changed to ultimately influence both of these set points. [SPEAKER_01]: still just a model, think most of the stuff genetically mediated, but yeah, that's his speculation.

28:14 [SPEAKER_01]: So in this model, the question asks, is this scale weight or body fat? [SPEAKER_01]: And in the model, as it's presented by Dr. Speekman, it says both, but the major regulator here, I would have to say, is probably body fat, but there are a couple other potential [SPEAKER_01]: influences here.

28:34 [SPEAKER_01]: One is just wheat, and that is known as the Gravitostat model. [SPEAKER_01]: I did a weird science monologue podcast on this. [SPEAKER_01]: So where this came out of this research group out of Sweden, they basically took rats, and they put the implanted weights in their bellies. [SPEAKER_01]: And they had him walk around, live their life, and they found the rats lost the same amount of weight that was [SPEAKER_01]: is this like the bones sensing additional weight that's signaling to the brain to eat less and move more so they lose the weight.

29:08 [SPEAKER_01]: And this ultimately spawned a bunch of studies where humans were wearing weighted vests for like eight hours, 12 hours, more hours per day. [SPEAKER_01]: didn't really pan out on weight loss, but there are changes related to the hormonal signaling out of the bony cells, the osteocytes that do seem to impact what's happening at the level of the brain with respect to hunger, so not nothing there, but not super strong.

29:31 [SPEAKER_01]: There's another sort of regulator what that has to do with muscle mass. [SPEAKER_01]: We call this the amino stat model and you can think about this like a thermostat but for protein. [SPEAKER_01]: So the body is really defending against loss of protein or gain of too much protein defending lean mass levels.

29:47 [SPEAKER_01]: There's less evidence for this and at the top end, like the body preventing, you can't gain any more muscle, but there's certainly some evidence about loss of lean mass. [SPEAKER_01]: And what we see here is that when people stop losing weight for example, and they start eating more calories, whether it's spontaneously or through a concerted effort, they are trying to we think that they're trying to restore the loss lean mass.

30:08 [SPEAKER_01]: That's the idea behind this protein leverage theory, this amino stats sort of model, but instead what they actually do is they restore a lot of fat mass, [SPEAKER_01]: which leads to the overwhelming influence on kind of body weight body fatness regulation. [SPEAKER_01]: We call this the likeostat model.

30:24 [SPEAKER_01]: This has the most evidence of any of these three sort of regulators where body fat is this active endocrine organ. [SPEAKER_01]: It's constantly sending signals to the brain to say, hey, look, we have a lot of energy on board or not enough. [SPEAKER_01]: And so the idea is that if someone's losing enough body fat, [SPEAKER_01]: that once they get close to this lower threshold, which again, it's genetically mediated varies amongst individuals, sends a signal to the brain say, hey, look, man, you got to stop moving as much and you got to start eating more.

30:53 [SPEAKER_01]: defending against further fat loss. [SPEAKER_01]: And then at the upper end, bodies full, energy stores are full. [SPEAKER_01]: You should reduce energy intake and move more, although we think that the environment may be overcomes that signal. [SPEAKER_01]: And that's effectively the root cause of obesity, if we had to reduce it down.

31:14 [SPEAKER_01]: I think to answer this, the weight and body fat are linked. [SPEAKER_01]: It's really difficult to lose weight or lose body fat without losing any weight. [SPEAKER_01]: That's challenging. [SPEAKER_01]: So I think they're both tied together, the big, the venn diagram, there's a lot of overlap in the middle.

31:28 [SPEAKER_01]: But I think that most of the set point and interventions that the body takes on as a result of getting closer to those thresholds or set points is mostly due to body fat versus straight up body weight. [SPEAKER_01]: But I think they're all involved. [SPEAKER_01]: Probably protein to the least amount, wait to the second least amount, and then the most is going to be body fat.

31:50 [SPEAKER_00]: Yeah, I do not have the amount of expertise with these kind of specific areas of research, but having listened to a lot of the general discourse around them in the scientific community over the years and then kind of your own deep dives into this. [SPEAKER_00]: I am unsurprisingly inclined to agree with many of your thoughts here.

32:11 [SPEAKER_00]: So it is a super interesting topic. [SPEAKER_00]: You're right that these things are super complex, interrelated. [SPEAKER_00]: In my, on my end, part of the reason why I think I have the approach that I do here is like I'm ultimately the vast majority of the time operating as a clinician here and so it's like when I'm thinking clinically it's like okay.

32:30 [SPEAKER_00]: Here's the patient in front of me. [SPEAKER_00]: What interventions or how can I help them? [SPEAKER_00]: What do I have available to me? [SPEAKER_00]: And these models while very interesting are not currently immediately applicable to like what I do with a patient. [SPEAKER_00]: They're like interesting in an explanatory way.

32:45 [SPEAKER_00]: But I'm not sitting patients down and suggesting that we implant like lead weights into their abdomen to facilitate weight loss as interesting as such an idea might be. [SPEAKER_01]: And I yet, and I will see, we'll see if that gravity model takes off. [SPEAKER_01]: Yeah. [SPEAKER_01]: We did best for everyone.

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