Metabolic Adaptation and Diet Dynamics with Dr. Eric Trexler

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This week on the podcast Mikki speaks to one of the OGs in the strength, fitness, diet and science space, Dr Eric Trexler. Eric was one of the first on the internet (it seems) to really dive into metabolic adaptation and what that means for anyone who embarks on a calorie restricted diet. Mikki and Eric discuss how this differs to the constrained energy expenditure model, the interplay of diet and exercise in both of these and strategies to help overcome for better overall health and performance. They also discuss how his understanding of metabolism has evolved over time.

Eric on Linked In https://www.linkedin.com/in/eric-trexler-19b8a9154/
Iron Culture https://podcasts.apple.com/nz/podcast/iron-culture/id1452114380
MASS Research Review https://massresearchreview.com/
Eric on IG https://www.instagram.com/trexlerfitness/?hl=en


Eric is cofounder of MASS research review and cohost on Iron Culture podcast. En route to an MA in Exercise and Sports Science and a PhD in Human Movement Science, he obtained extensive experience in research design, data collection, and advanced statistical analysis. To date, he has published 58 peer-reviewed papers pertaining to a wide range of health parameters in diverse participant populations.

Since graduate school, he has pursued multiple entrepreneurial endeavours related to health, wellness, and technology. He is currently a postdoctoral researcher at Duke University where he studies health behaviour, health disparities, and the intersections between physical activity, nutrition, energy expenditure, and cardiometabolic health.

Contact Mikki:
https://mikkiwilliden.com/
https://www.facebook.com/mikkiwillidennutrition
https://www.instagram.com/mikkiwilliden/
https://linktr.ee/mikkiwilliden

Creators & Guests

Host

Mikki Williden

What is Mikkipedia?

Mikkipedia is an exploration in all things health, well being, fitness, food and nutrition. I sit down with scientists, doctors, professors, practitioners and people who have a wealth of experience and have a conversation that takes a deep dive into their area of expertise. I love translating science into a language that people understand, so while some of the conversations will be pretty in-depth, you will come away with some practical tips that can be instigated into your everyday life. I hope you enjoy the show!

Transcribed using AI transciption; erros may occur. Contact Mikki for clarification.

00:01
Hey everyone, it's Mikki here. You're listening to Mikkipedia, and this week on the podcast, I speak to Dr. Eric Trexlar. Now, Eric is one of the OGs in the strength fitness diet and science space. He was one of the first on the internet to really dive into metabolic adaptation after his own experience as a pro bodybuilder, and really translate sort of what

00:30
that meant for anyone who embarks on a calorie restricted diet. And this is the topic of the conversation that Eric and I have today. We also discuss how metabolic adaptation differs to the constrained energy expenditure model. And you'll remember, I'm sure, that I have spoken to both Herman Ponzer and Andrew Best on the podcast about this, as Eric is now part of their research lab.

00:59
Eric and I also discussed the interplay of diet and exercise in both of these and importantly, strategies that help people overcome this metabolic adaptation for better health and performance overall. And I mean we talk about so much but something which I found super interesting was just you know how Eric's understanding of these this area these concepts has changed over time given his experience, his research and everything like that. So

01:27
This is a geeky conversation, but Eric is so good at translating science into language that anyone can understand. So Eric is the co-founder of the Mass Research Review and co-host of Iron Culture podcast, and you might already know that he sort of works alongside the other Eric, Dr Eric Helms, and others in these endeavours. En route to an MA in Exercise and Sports Science and a PhD in Human Movement Science,

01:56
Eric obtained extensive experience in research design, data collection, and advanced statistical analysis. To date, he has published over 58 peer-reviewed papers pertaining to a wide range of health parameters in diverse participant populations. Since graduate school, Eric has pursued multiple entrepreneurial endeavors related to health, wellness, and technology. He is currently a postdoctoral researcher at Duke University, where he studies health

02:25
health disparities in the intersections between physical activity, nutrition, energy expenditure and cardio metabolic health. In addition of course to Iron Culture, Mass Research Review as I already mentioned. And I've got links as to how to track Eric down in the show notes for this episode. Before we crack on into it though, I'd just like to remind you that the best way to support this podcast is to hit subscribe on your favourite podcast listening platform. Because that's

02:54
increases the visibility of Micopedia in amongst literally thousands of other podcasts that are out there. So more people get to learn from the experts that I have on this show, including Dr Eric Trexler. All right team, enjoy this conversation.

03:12
Um, Eric, thank you so much for taking time with me this morning. Really appreciate having this opportunity to pick your brain directly, as opposed to just delve into all of the work that you put out on the interweb for us to get amongst really with all of the stuff that you do. Yeah, yeah, I appreciate it. It's great to be here. Great to chat with you. And thanks for supporting Mass by the way. That's really nice of you. Oh, you guys put such great information out there. And...

03:41
I believe that mass started in maybe 2017, was it? Yeah. And I remember thinking, I think I'd learn a lot from this, even though I'm not bodybuilding specific at all, actually. I'm an endurance athlete, but I just really enjoy the science and I've learned so much over the years. Yeah, and you've probably noticed over the years we've kind of not intentionally pivoted, but as our interests have evolved as writers, you know, we've really branched out from being a very bodybuilding.

04:11
building focus thing and gotten into a lot more general fitness, which has been fun. Yeah, it would be. And I've often thought that bodybuilding was like the... it's an extreme endeavor. You learn a lot from that, that you can then translate to that sort of general population. And of course, I work a lot in fat loss and in helping people with their physique goals. And it's just a continuum, right? Like it's a spectrum of what people want to achieve. Yeah. Yeah, absolutely.

04:41
Yeah, Eric, before we delve into metabolic adaptation, which is what I'm super interested to talk to you about, can you give us, for those of you who are somehow not familiar with you, a little bit of your backstory and how you even sort of got interested in this area? And this can be as long or as short as you want. Sure. Yeah. So how I got interested in metabolic adaptation, you know, is mostly by...

05:09
experience. I kind of experienced it firsthand. And at the time, you know, the first time I got really, really lean to compete in a bodybuilding competition, you know, I was not really all that into the science yet. And so it was certainly an interesting eye opening experience, but I didn't really understand what was going on. Were you quite young at the time? Well, I my first

05:37
competition was in 2011. So I think I was like 21 ish around there. Did a couple other shows two years after that. So I actually did a competition, a series of competitions right before I started my master's degree. And that was the first time that I got really lean and kind of reached the weirder elements of metabolic adaptation and kind of

06:07
Had a really challenging post competition recovery process and was just like this physiology is clearly extreme, but I'd like to learn more about the mechanisms that are underlying some of these extreme outcomes. And, you know, I, the way I usually view it is if we can understand why something's happening, perhaps we can.

06:30
Unlock some ideas about how we might mitigate that how we might plan around it or at the bare minimum plan for it you know to understand how to. Navigate a challenging situation you first have to understand what the challenges so so that's how i got interested in metabolic adaptation and. I really don't write in so the first paper that i wrote in graduate school was a review paper.

06:58
for the JISSN for that journal, which was a big review paper about metabolic adaptation as we understood it. And I wrote the majority of that paper in 2013 and it was published in 2014. And that kind of set me on this trajectory to keep digging into it. At that time, there wasn't a lot of bodybuilding research going on. There wasn't the metabolic adaptation research

07:29
had been done, but was kind of entering a quiet period. There was some good stuff in the late 90s, early 2000s, give or take. And it seemed like around 2010, it was starting to kind of slow down a little bit. But then around 2013, 2014, there was kind of this new wave, this new push, with more bodybuilding research coming out in the last few years, more metabolic adaptation research. So.

07:58
It's been fun to be engaged in an area of the literature where there is still so much to learn. It can be really frustrating when you get into a research area that you think is cool and then you find out, oh, we've kind of like really covered a lot of it with the research already. So now you're trying to kind of carve out this little tiny element that you can kind of add to the picture. But with metabolic adaptation and it's kind of...

08:28
parallels and overlaps with things like exercise energy compensation and relative energy deficiency in sport It's a topic where there's still a lot of meat on the bone and a lot of questions to answer Yeah, that's really nice and am I correct in thinking that you've recently maybe over the last year or 18 months shifted your Professional work to be in Herman Ponce's lab like is that right Eric? So I was

08:57
Basically out of the academic world for about five years doing, uh, doing my own projects in the fitness industry. And I decided I wanted to get back into research and, uh, you know, Dr. Ponser is fantastic. He was doing my favorite research that was happening by far. And, uh, just got really fortunate that.

09:24
He had an opportunity available. He extended that opportunity and it's a pleasure working in Herman's lab. He is absolutely brilliant. And I love the lab environment. There's a really, there's like a palpable enthusiasm about kind of chasing down these fun, exciting questions. And there's this strong sense of optimism that we have the capability.

09:51
to chase these things down and really get some answers so it's a fantastic work environment a fantastic scientific environment in that lab and what's really interesting is you know Herman Ponser has been studying exercise energy compensation for quite some time. And I should clarify that when I talk about metabolic adaptation I'm usually talking about reductions kind of adaptive or compensatory reductions.

10:20
in energy expenditure in response to underfeeding. So, so being in a diet induced caloric deficit. Well, as I was kind of working on all that stuff, uh, you know, 2013 and beyond, Poncer's lap really started picking up steam, uh, with, with the paper that comes to mind for me as kind of really taking off on a, on a trajectory for them was, uh, in 2016.

10:47
There is a great paper that Herman and his colleagues published looking at exercise energy compensation, which is an adaptive or compensatory reduction in energy expenditure in response to very high levels of physical activity. And so to me, it was really fascinating to kind of say, okay, we may both be looking at different sides of the same coin here. You know, yeah, we're seeing this.

11:15
shortage of energy resources, these compensatory mechanisms to try to navigate that shortfall or to become more efficient, which is of course in our best interest for survival purposes. And what's really fun about being in Herman's lab is we get to look at this general problem statement of there's a shortfall of energy, whether it's coming from

11:42
you know, minimal dietary intake, excessive exercise loads. And we're actually housed in the department of evolutionary anthropology, which is a huge difference for me. I'm used to being in exercise science departments. So it's, I never get tired of, you know, going to the lab seminars or the department seminars on Fridays. And I have no idea what we're talking about. You know, it could be something very in line with what I do, or it could be something about.

12:12
you know, a primate species that hasn't existed for hundreds of thousands of years. I don't know what we're going to be getting into, but it's very fun and intellectually stimulating. I can imagine, actually. And being in an environment with a range of people with different zones of genius just allows you different, like you get a different perspective, then you can have the opportunity to think about something in a way that you might not have. Oh, yeah. Yeah.

12:42
The collaborations that i've really come to appreciate and cherish in terms of growth opportunities are the ones where i'm teaming up with people from completely different backgrounds where you're learning from the same textbooks you have the same blind spots you're basically of course

13:09
Every individual is a little different but but you're largely on the same track it's really fascinating to team up with someone who's gonna look at a problem from a completely different perspective and the. The process of reconciling those different perspectives is where i think. A lot of the creativity and innovation happens a lot of the growth and knowledge and so right now i'm kind of working on this project with with people from.

13:36
several different areas, you know, we got people who are evolutionary anthropology, people who are nutrition, people who focus on exercise, people who work with, you know, the best of the best Olympic level athletes. And we're putting our heads together on this project. And, and, uh, it's just really fun to get all these different perspectives together and say, well, we need to figure out some consensus. And, uh,

14:02
now we have to figure out what the heck everybody's talking about here. And usually, you know, you fill in each other's blind spots, fill in some gaps that we all have that are kind of specific to our field. And it ends up painting a really comprehensive picture. I can imagine. And I mean, I am intending to ask you what you're working on later on in the podcast, you know, but can I ask already? Like, are you able to share any details of that project before we dive into the...

14:31
the depths of metabolic adaptation? Yeah, I can say broadly what I'm working on falls in a few different bins. On one bin, I am doing some research related to cardiometabolic health. And it's a really cool project where we are looking at individuals who work in a pretty high stress occupation, pretty sedentary occupation.

15:00
and an occupation that tends to be distributed in rural communities where we see different health behaviors and different access to health care and different health related resources. So on one hand, I'm doing this very like clinically focused work about physical activity and nutrition and people who are busy, stressed and don't have a lot of access to...

15:27
easy access to gyms, healthy foods, time to cook those healthy foods, things like that. On the other end of the spectrum, we're doing some stuff with athletes. In Herman's lab, we're just fascinated in looking at the extremes of energy expenditure. So we've got some projects in that realm as well. I think a lot of people believe there's two ways to approach a theory that a lab investigates.

15:57
What are the concepts related to exercise energy compensation is that. There is probably a. Something of a ceiling in terms of kind of a maximum sustainable amount of energy that a person can burn for months and months on end. I am that over time if we try to exceed that will eventually kind of you know through compensatory mechanisms find our way to that ceiling and so.

16:23
Some people when they have a theory like that they want to try to find ways to prove it. We're trying to find ways to disprove it you know we're trying to seek out if someone were to exceed where we think the limit is who might be doing that. So we've got some cool research in that area and i'm also you know another kind of third bin is. Reconciling like i said you know with with exercise energy compensation and metabolic adaptation.

16:54
We're seeing essentially as a metaphor people. Are it's like putting your body on low battery mode like with your smartphone right where okay maybe we will refresh all those apps in the background will kind of cut down the non essential tasks just to save battery life in a similar way we're seeing these different applications where people who are under fueling or exercising to an excessive degree.

17:21
they are kinda going on low battery mode and conserving energy and we still have a lot to learn about. What the mechanisms are in terms of where exactly is that energy coming from. Who seems to be adapting more than others if there is significant variation among individuals and really figuring out you know one of the things that most interest me is. As we start to unravel those things with metabolic adaptation and.

17:50
exercise energy compensation, the question to me is, are we looking at two related things that are complementary? Or are we looking at two manifestations of the same underlying effect? And I don't know if we necessarily have a clear answer to that yet. But I'm really intrigued to see if we can find that. How do you test that?

18:20
energy compensation model and someone exercising to the extreme, I guess that's a behavior that then, I guess by definition, they're not putting in the amount of energy they require for that. Yeah. Or is it just a difference in sort of how an individual behaves or yeah, how would you test it? It's really difficult to test. And the reason is, you know, especially if you want to start parsing out.

18:47
Inter individual variation right so this person. Adapt more than that person if you want to do that the best way to do that is with we actually just published a paper with. Zach robinson and a bunch of colleagues james steel mike zordos eric helms some others we published a review paper because a lot of people in the strength and conditioning world talk about. Inter individual variation this.

19:17
athlete responds better to high volume, this athlete responds better to high intensity, and so on and so forth. It's actually from a statistical perspective really hard to make that determination. In order to do it, the ideal scenario is to do a crossover trial where you repeat at least one condition. For example, if you want to figure out if an athlete responds better to high volume or low volume, you'd have that same athlete do a high volume.

19:45
phase of the study. Then a low volume phase of the study and then they would repeat either a higher low volume phase of that study so that you can actually look at how they respond to the same intervention twice and kind of it helps you kind of parse out all these different sources of variation. The challenge with exercise energy compensation, the thing that makes it very hard to study is that this is a long term adaptive response, right? So

20:13
We often, for now, it seems like the maximum sustainable energy expenditure that people can really keep up in the long term is about 2.5 times their basal metabolic rate. So 250% of their BMR. But if you ask me today, can I burn five times my BMR? Of course you can. Sure. There are people who today will do that on this planet.

20:41
If you ask me, can I do it for the next three weeks daily? I would say, sure, probably so. It's not gonna be your favorite three weeks, but you can do it. What we see is that there's this really steep drop-off when we look at the relationship between maximal metabolic capacity or metabolic scope, multiples of BMR, and duration of activity on the x-axis. So for a very short period of time, you can basically burn as many calories as you wish, if we're talking about over the course of

21:11
hours or a few days but overtime when we look over the span of six seven eight nine months we see that people really do tend to fall back down to that that. Apparent ceiling of about two point five times bmr now the tricky thing there is good luck doing a crossover trial where you are gonna get someone to. Even try to elevate you have someone who's untrained at rest.

21:36
You get them to elevate their metabolic scope to many multiples of BMR. You watch that process unfold over nine months. Then you do a washout period. Then you do it again. Then you do another washout period and you do it again. You know, you start to see that there's so many practical challenges in trying to observe this response from start to finish in an experimentally induced manner. Um, however, you know, there are ways to.

22:04
kind of get little glimpses at it here and there and to kind of directly answer your question of how would we even begin to parse out differences or confirm similarities between metabolic adaptation and exercise energy compensation. I think it comes down to if we can identify some key mechanisms involved with what actually where's the energy coming from? And that's a surprisingly hard thing to measure.

22:33
in some cases. But I think if we could do a study where we induce a substantial or find people who have a substantial degree of exercise energy compensation, if we could tie that to a reduction in the hormone leptin and if we could correlate that change in leptin to a reduction in...

23:02
where i should frame it differently if we can tie that reduction in left into an increase in the efficiency of skeletal muscle during very low intensity activities. I think that would be a recipe where you could make a pretty strong case that in metabolic adaptation and exercise energy compensation. If that mechanism holds an exercise energy compensation we might be looking at.

23:30
two different manifestations of just a simple energy shortfall. And we'd say when there's a shortfall of energy, either through insufficient intake or excessive output of energy, leptin drops. That drop in leptin appears to have an effect, at least in the case of metabolic adaptation on skeletal muscle efficiency during low intensity activities. And that seems to have a disproportionate impact not on resting metabolic rate.

23:59
but on non-exercise activity thermogenesis, the calories we burn during activities of daily living. And I would say to zoom out a little bit and provide some clarity, that is one of the most challenging things about studying both metabolic adaptation and exercise energy compensation, is that it's very easy to estimate someone's resting metabolic rate via measurement. And it's,

24:29
expensive but easy to measure someone's total daily energy expenditure. Like doubly labeled water? Is that what... Yeah, doubly labeled water is our preferred method. It's the gold standard. Like I said, very expensive. For a while there, you could only really afford to do it on small rodents. But now we've gotten to the point where Herman, before I joined the lab, they did a study with doubly labeled water on elephants actually. Oh, goodness.

24:56
Yeah, the dose actually is scaled to body mass. So we worked our way all the way up from mice to elephants. Yeah. So we can do humans, no problem. But yeah, so the challenge is we can measure resting metabolic rate with indirect calorimetry. We can measure total daily energy expenditure with doubly labeled water. But the everything in between is what's really hard to measure in a reliable way if we want to capture all of it, right? So...

25:25
We can put someone through a standardized exercise test and see how much they burned, how many calories they burned during that exercise test, but are we actually gonna be getting just the exercise component of their day-to-day normal training? It's really hard to kind of suss that out. And then with non-exercise activity thermogenesis, it's infinitely harder. I mean, we just, it's really difficult to, in a free living individual, get these little pieces.

25:54
Some people would say, well, okay, no big deal. We'll have them stay in a metabolic chamber where we can actually look at, you know, specific compartments or components of energy expenditure. But the problem there is we're taking them out of their normal environment and we are dramatically modifying their behavior. You know, what you are in this tiny little room that's kind of capturing all the gases, that all the air that you're breathing out

26:24
We can get a good estimate of your energy expenditure when you're at rest when you're sitting when you're doing different activities in there. What they're not they're not really what you do on a day to day basis you know we're not getting you walking down your mailbox we're not getting you walking from your car to your desk at work. So we're really not getting a valid picture of what your expended energy expenditure looks like on a normal day. We're getting a picture of what it looks like when.

26:50
you basically are living in a large cage for 23 and a half hours. So yeah, it's a fascinating area of research and it is, I really like it because despite how challenging it is to study, there is so much potential for application and there's so much utility and it's so interesting to feel like the way we utilize energy is this

27:20
aspect of how the human body works you know it almost feels like there's in the human body instruction manual there's just this giant section missing and it's like. A foundational section that we should understand but there's still just so much to learn and it's almost surprising. That we've we've made it this far in science but but still have so much to learn about this very basic element of how our body functions.

27:49
Yeah, so interesting, Eric. And I think from a practical perspective, I'm trying to think through where this is relevant to sort of people listening. And obviously it is, well, from a metabolic adaptation perspective, the underfeeding, that would be someone who is in a fat loss phase or has been in an extended fat loss phase. And then with the energy compensation model, I'm thinking of athletes like...

28:14
particularly endurance athletes. And I've talked to Drew Best actually on the podcast of his work in Herman's lab. That was maybe a year ago and he was sharing details of his study at that time. So with the energy compensation model, if I'm a cyclist and I've got a power meter on my bike,

28:38
and it tells me I've burnt X number of calories because I've been writing at 240 watts for three hours. And it's got all of my data in terms of my body weight, my fitness level, VO2 max, et cetera. Is that a reliable indicator of actual energy burnt in that situation? Or like how much trust can we put in that? Cause I guess I'm asking this because these are questions that I get as a nutritionist. And then in the back of my mind, I'm like,

29:07
because it relates to therefore how many calories do I need to then eat in order to maintain my weight, lose my weight, et cetera. These are the practical questions that I get asked. Can you answer that? I will give you two different layers of an unsatisfactory or unsatisfying answer. So the first question is, does that give you a reliable estimate of energy burned in the moment?

29:34
It gives you a number that for an individual ought to correlate with energy burned, but in terms of giving you an actual, you know, here's how many calories were burned. Unfortunately, we can't really get that. The reason being that muscular efficiency is not this like completely uniform thing. So for example, you know, you could take a person who's relatively untrained.

30:02
have them do a training program and their efficiency doing that same exercise could change to a meaningful degree so even if they're doing the same exact workout with that power meter and everything's the same. There could be a change in the amount of energy burned to get that task done and then if we add in elements like under feeding or really excessive workloads again we can see some of these adaptations and energy expenditure that may impact that number.

30:30
But like I said, that's just when we're looking at it in terms of in the moment. What's really important for the application of that. So, you know, people ask this all the time. They say, how many calories do I burn when I run this distance or, you know, or something like that? And the answer is it kind of doesn't matter because what we're really asking is what we're acting upon from that question.

31:00
is not how many calories did you burn during that one and a half mile run. It's on a day where I ran one and a half miles, how much did my total daily energy expenditure change? Right? So even if we can figure out exactly how many calories were burned during that exercise

31:21
Not necessarily with wearables, it's almost better to just kind of take it all the way back to the, uh, the textbooks of, you know, like the ACSM manual and you plug in all the values. So we can get an, an okay estimate. It's not going to be perfect. Um, but what's. Dramatically harder to estimate is on a day where you did that exercise. Did you have reductions in other components of energy expenditure that attenuate some percentage of that caloric expenditure beyond the resting value?

31:51
And that's where we start to say, yeah, you probably burn more than if you hadn't done anything that day. But when we start to get down to really granular estimates, it gets extremely, extremely difficult to do that. Yeah, because I have had conversations with triathletes. And if they look at their garments over the course of like a Saturday where they do a brick session and they're doing a swim and a bike and a run and they're like, I've burnt

32:19
like four and a half thousand calories, like, and their coach is saying to them, you need to replace those calories. So you need to get in that four and a half thousand calories in addition to your, or over the course of that day, including your just general energy expenditure. So that value isn't necessarily correct because is it?

32:41
by someone who just said. No, no. That number's really, I mean, the wearables, they just don't do nearly a good enough job. And even the things built into exercise devices, they just don't do a good enough job to act upon it in terms of an actual caloric prescription resulting from that. I will say this, it's good to be mindful. So even if your fitness tracker is not giving you a number that is valid.

33:09
It's good to be mindful of, for example, if you know that it normally tells you, you burn 2,800 calories a day, you made some changes to your lifestyle. Now it's telling you that you're burning 3,800 calories per day. You can probably infer that you're moving more than you used to and burning more calories than you used to. Uh, so you can make these pretty basic inferences like that, but in terms of, you know, down to the calorie, um, replacing this with that, um,

33:36
You know i burn this many so i need to eat back that many i would not use wearables or you know accessories built into different exercise equipment in order to inform those types of decisions. Usually it's you know we see this in two different applications right so we got endurance athletes who will say well my things that i burn four thousand calories i need to eat your place those well. You might as well.

34:03
Right? So endurance athletes, usually the issue is under fueling, not over fueling. And if you're over fueling, you'll figure that out pretty quick. If you're monitoring your body weight, you'll start to see it moving up and you say, Oh wow, it looks like I'm, I'm over fueling, so I'll remove this, remove that, and we're good to go, right? No harm, no foul. If you're keeping an eye on body weight, you can rectify that very, very easily. Another application where we see this, this type of thing being done is with weight loss and people will say, you know,

34:32
Okay, well, I burned this many calories on my treadmill walk, and then I did this many calories in the gym. So I put that all together and I guess I can justify having a little bit more food because I burned a little more. I never encourage people to start using wearables or other calculations, calculating devices to start making those types of trade-offs because usually like it's the inverse of the endurance athlete. With an endurance athlete, the issue is.

35:00
almost always under fueling not over fueling for people who are trying to do these kind of trade offs in the context of a weight loss phase. It's usually it usually starts to feed into a pretty problematic view of the relationship between exercise your body and your dietary habits. It can feed into some of these binging and restricting cycles and

35:27
It'll often just lead you astray in terms of the actual mathematics of it. Usually you'll overestimate how much your exercise impacted total daily energy expenditure through that kind of compromise system, you'll kind of infer that you can add more calories than you actually ought to. Your weight loss progress will likely stall and ultimately it'll just kind of undermine your efforts and lead to some frustration.

35:54
No, that's really great actually. And I like how you've separated the two out, which makes, because I often think endurance athletes do make that mistake of under-fuelling or realizing they could actually, they could eat a lot more and their weight would stay stable, but there's that fear that they'll gain weight because of that, you know, because that's the type of sport they're in where, you know, the power to weight ratio is quite important. So I often see that under-fuelling aspect.

36:24
I guess it's just a trust thing, right? You've just got to trust, like actually, I've just got to eat more and evidence builds confidence. They'll see that they're able to eat more and not necessarily have that weight to change their theory. Yeah. And, you know, there are strategies to help build that confidence. You know, it doesn't have to be a blind leap of faith. You can say, hey, you know, if you're really concerned about it, why don't we implement some form of food tracking or food journaling and some form of weight tracking?

36:53
they're comfortable with it. For certain people, that might be contraindicated by a history of body image concerns or disordered eating habits, but if there are no contraindications, sometimes those things can instill some additional confidence. People will think, oh, if I touch that extra 100, that extra 80 grams of carbohydrate a day, I think I'm just gonna pack on a bunch of fat mass and get slower. Sometimes it's easier to just show them. So, well, I tell you what.

37:23
once the scale hits this number, you win and we'll back off. And the scale, you know, it's not going to hit that number anytime soon, right? So you can kind of say, I don't need you to take a leap of faith. Let's just trust the numbers and go with it. You know, it's interesting because often people think that tracking itself will bring about these disordered behaviors and these sort of obsessive thoughts. But actually, for a lot of people, it does exactly what you've said. They've catastrophized in the head what the problem will be.

37:52
and you've just provided them the evidence that in fact is actually going to be okay. Yeah, and there have been, there was recently a fairly sizable randomized controlled trial where they tried to figure out, you know, because there's all this literature on diet tracking. And of course, obviously diet tracking is correlated with disordered eating habits and body image concerns because people who have disordered eating habits or

38:19
no excessive kind of pathological body image concerns they track their food because they're trying to you know that their body size and body image so that you know it's. Certainly very intuitive that those things would correlate but the question is is there a causative relation there a causal relationship where.

38:48
When you start tracking you develop disordered eating patterns and body image excessive body image concerns and the best evidence to date would suggest that's not the case that we will when you. Do a randomized controlled trial where people are randomly assigned to track their food using a phone application or not track their food using a phone application you know as long as you do you know in this particular study i'm thinking of they did a.

39:15
fairly simple screening process, just from an ethical perspective to make sure that people as they were entering the study weren't already really high on the list, very high risk of disordered eating. But yeah, for people who were not very high risk entering that study, there was really no causal relationship to be spoken of there. And so that's a good thing. But the thing that can be a little bit unfortunate is not...

39:44
everyone knows if they're going to be relatively high risk for forming disordered eating patterns or body image concerns. So it is the type of thing where for someone who's never really given it much thought, it's worthwhile if they're just tracking their nutrition for the first time. The evidence I don't think is strong enough to suggest that we should assume that it is a dangerous intervention. I think the opposite is true. I do not believe.

40:11
that it's a dangerous intervene intervention for the vast majority of people. But it is good to keep your eyes open for any red flags. And if you start to see like, Hey, once we started tracking food, things got really uncomfortable. There was a lot of body checking and talk about weight and body image and things got a little bit off the rails. Just keep your eyes open for it. And, and, you know, it should become pretty apparent if you're communicating well with your client, your athlete. And at that point you say, okay, now we know that.

40:40
that quantitative diet tracking is not for you and will kind of pivot to a different strategy of which there are many. Yeah, yeah. No, that's awesome, Eric. And I've completely gone off track with what I was hoping to chat to you about. That's such a tangent. Yeah, no worries. But what I would like to bring it back to actually, when you were discussing the energy compensation model and metabolic adaptation, and you mentioned there could be this one thing with LEC.

41:09
in, like maybe, and you would just, I don't know whether it was probably just a, like a smart hypothesis, like an informed hypothesis, but in either of these models, is body weight a factor, like with metabolic adaptation or with energy compensation, not body weight, sorry, body fat levels, like how does that play into it?

41:36
the first literature that really started nailing into that concept. I guess if we want to go all the way back, it kind of goes back to the Minnesota starvation experiment where conscientious objectors who were not entering combat roles in world war two were semi-voluntarily entered into this study. They were, it's called the semi-starvation experiment because they were semi-starved.

42:05
and they got very, very lean. And their body fat got as low as a person would ever want it for any fitness or athletic application. Can you remind us how long that was, Eric? Oh, the thing about that study is that it was published as a two-volume book that I think is a total of like 600 pages. So every time you want to go back and check a quick thing, you have to like dig into this giant.

42:34
PDF that's like a thousand pages long. But it was months, right? It was months, yeah. It was not your typical like little 12 week study. I think it was, I think, and the other thing that's tricky with it is that there were many phases. There's kind of a dieting baseline phase, dieting phase, refeeding phase, controlled refeeding, and then ad libitum refeeding. So there's all these numbers of weeks and months that get jumbled up. But if I had to guess, I'd say the weight loss phase, I believe was in the five to six month range, roughly.

43:04
And am I right in thinking they did the baseline phase and their caloric intake was around the 3,000 or 3,200 calories or something and then the weight loss phase was like almost half of the usual intake? Is that right? That's quite impressive. Yeah. The weight loss phase, they were around that like 1,600 calorie a day range and these were all adult men. And they were doing...

43:34
They had a prescribed amount of physical activity to do every day as well. Um, so yeah, I mean, they, they were on a, not a shockingly low cal, you know, you'll see, uh, male physique competitors who are eating, uh, diets in that range. Um, and doing similar amounts of physical activity. So it's not unheard of. It's just a level of forced compliance that, um,

44:00
You know if you eat that little you move that much for that period of time you will end up getting lean whether you like it or not. And so these individuals got very very lean. And it was kind of the first study where they said hey for these individuals like they are experiencing a reduction in energy expenditure that is really pronounced. What is a degree that far exceeds the actual tissue loss that they experienced. And so.

44:31
You flash forward to the 1990s, early 2000s, Rosenbaum and Liebel did a series of really, really good studies. They usually would do studies where they would take an overweight or obese sample of individuals, people with overweight or obesity. They would have them lose at least 10% of their body mass, and then they would kind of remeasure their variables.

44:59
and very conclusively is that when people lose fat mass, fat cells, they don't go away, but they shrink and they have less energy in them. And when that occurs, they produce less leptin. So circulating leptin levels go down. The amount of leptin interacting with receptors in the hypothalamus of the brain goes down. And this seems to be a key mediator of metabolic adaptation.

45:29
And probably the best evidence for supporting that is the fact that Rosenbaum and Liebel found if you just inject people with a bunch of leptin, what do you know? You cured metabolic adaptation. Pretty much everything reverses very, very rapidly despite the fact that these individuals are still at a weight reduced body composition. So yeah, absolutely fat mass plays a big role.

45:58
It is worth noting that leptin can change in response to other things as well. So being in a caloric deficit, having an energy shortfall in the immediate time frame also can cause pretty precipitous drops in leptin. If you just began a fasting phase today and we measured you in 24, 36 hours, your leptin levels would be considerably lower. So there's these kind of dueling.

46:26
factors that modify leptin levels. There's adiposity in the longer term scale and then the acute energy deficit in the short term scale. So that's where leptin comes into play. And leptin, like I said, it feeds into these receptors in the hypothalamus. And the reason that matters is because the hypothalamus is a remarkably consequential structure in the brain. Most of your brain is pretty consequential. You need that.

46:56
But the hypothalamus is so critical in managing a variety of different outcomes in the body. And when you think about all these different, for example, hormone cascades, testosterone, estrogen, thyroid hormone, all of these hormone cascades ultimately work their way up to the hypothalamus. It's the original kind of starting point for, you know, the hypothalamus releases this, which releases that, which releases that.

47:26
testosterone estrogen thyroid hormone. So there are these very wide ranging multifaceted physiological effects when something is impacting the hypothalamus. Hypothalamus is involved in temperature regulation even. And what's really fascinating about the hypothalamus is there have been these ablation studies in rodent models where they will do an ablation.

47:55
of certain clusters of neurons in the hypothalamus. And if they do it one way, you know, at one particular region of the hypothalamus, they will induce a level of hyperphasia or excessive hunger that is so severe that laboratory rodents will literally have such a ravenous appetite that they eat to the point of accidental suffocation. Oh, geez.

48:21
they will be eating that ravenously that they will choke on their food and die in some cases. And yet, you can, by doing a different type of ablation to a different area of the hypothalamus, knock out appetite to an extent that the rodents almost voluntarily starve to death because they just have absolutely no appetite. So the hypothalamus coordinates our energy intake and our energy expenditure.

48:51
For example, bring it full circle as a bodybuilder. When I did the first competition that weren't the first one where I got really lean, it wasn't just like I looked at my numbers and said, Oh, wow, this is an interesting discrepancy. I believe my energy expenditure is low. It's it's a full body experience, right? I mean, testosterone was well below the reference range. Thyroid hormone was well below the reference range.

49:19
You're lethargic, you're freezing cold all the time. You're, you know, you have no libido. You can feel that your hormones are completely out of whack. Your appetite is not high. It's like at a different level that you didn't really know was possible. Right. Uh, and even just weird things, your hair grows slower. Your fingernails grow slower. It's so fascinating to watch how the hypothalamus integrates this information of an energy shortfall.

49:47
and has these just robust, wide ranging down, this massive effect of down regulating all these non-essential tasks. And so one of the things I'd really like to look into, like I said, I don't think we quite have the data yet, but I'd be really intrigued to see how really, really high levels of physical activity impact leptin independent of body composition.

50:15
Right. So obviously endurance athletes who are racking up a ton of training volume, they're going to be pretty lean. Leptin will be pretty low, but I'd love to see if we can get a kind of in a longitudinal sense, an idea of when you really ramp up your training volume from high to extremely high, even if your body composition doesn't change, what happens with those leptin levels, uh, and. More pertinent.

50:44
to the question, how might that impact things like your resting energy expenditure or your non-exercise activity thermogenesis? What about like long distance swimmers? Would they be a good population to look at? Their endurance, their generally their body fat levels are going to be higher. So you'd imagine that even though, but they do hours and hours of swimming each week. Could that be a good population? A small population. It could be.

51:14
And I don't think that other endurance athletes are too lean for us to look at this. Like, I think they're still, if leptin is playing a role in the way that I suspect it might be, I think we should still be able to discern that even among leaner populations. But I do agree with you that if we were going to look at it in a longitudinal sense and try to really identify the isolated impact of

51:44
kind of transient changes in training volume, then it would be a lot easier to do that with a population that had higher body fat levels at baseline. So that would be probably a really ideal population to do it in. Yeah, yeah. Interesting, Eric. And then of course, we're talking, you mentioned your own experience and not just you, but in the sport that you're in, or you were in, like physique sort of sports.

52:12
this is something that happens or could be an issue for just people in the general population, doing a fat loss type approach. So at what point does it become, I guess, an issue for that general population? Is it the person that has plateaued, like a legitimate plateau? It's not just the effort that's plateaued, it's their actual, you know, they're doing everything after three or four weeks, nothing's changed. Is that metabolic adaptation? Is that...

52:41
Is that the explanation there? Well, the thing about metabolic adaptation in terms of practical application is that for now, the best that we can do is understand that it exists and plan for it. So metabolic adaptation is not going to single-handedly put up a brick wall that makes it such that you are now unable to lose additional weight.

53:11
What metabolic adaptation seems to do in the literature is apply a little bit of extra friction. So there have been a series of really great studies by Martens and colleagues in the last few years. And they've looked at this a number of different ways. And I love the way that they framed it in multiple different ways, because it makes it very tangible, very accessible and very practical. So for example, there was one study where they found, yes, there was a correlation here.

53:40
people who experience greater metabolic adaptation lost less weight. But in the vast majority of folks, what that ended up looking like was losing over the course of the study, perhaps you lost 11 kilograms instead of 13 kilograms, right? But you lost 11 kilograms. That is a substantial and a clinically relevant degree of weight loss. It's not like you lost two pounds, hit a brick wall because you got metabolic adaptation and that was that, right?

54:10
Another way that they framed it, which I think is really helpful is, um, it was a study where instead of saying, Hey, we're going to do a weight loss thing for like 16 weeks, they said, you're going to keep on doing this weight loss program until you get to a target weight. And the question is not how much weight do you lose? It's how long does it take you to get to the target weight loss? And what they found again was a correlation where they said, Oh yeah, the people with more metabolic adaptation.

54:40
It took them a longer time to get to their target weight, but they did get there. And the difference was a matter of just like a couple extra weeks. Right. So I think that's probably the best way to talk about metabolic adaptation as it pertains to weight loss is not, um, the idea that it causes plateaus, but the idea that it'll most likely be there for most people, for some people, it might be a larger effect for others.

55:10
It might be a smaller effects but it'll probably be there in some. Magnitude and so the question is you know. How do we navigate that situation so that we overcome the friction that is ultimately being applied there so i like to really focus on not will we be able to overcome a plateau or will we be able to.

55:37
When this wrestling match against our metabolism cuz that's really not what's going on the question is really you know. If you know it's coming and you have your eyes open and you're kind of making adjustments as you go

56:06
You know, the folks who took an extra couple of weeks to get to their target body weight, if they were working with a coach in an individualized manner, rather than being in kind of a big cohort of a study, I would venture to guess that a coach with a good eye, um, who is really skilled and had an eye out for metabolic adaptation, probably could have gotten right back on a trajectory that matched anybody else in that study. Um, so, so it's about, um, knowing.

56:35
that this exists and knowing how to account for it or accommodate it and it's it's very simple just by making additional incremental changes you know so you may indeed reach a plateau at some point. All that tells you is that you probably do need to make another incremental adjustment to what you're doing so that you're reestablishing a larger energy deficit. I like to always remind people that metabolic adaptation is not a rule.

57:03
It's not of a limitless magnitude. It's not like your body has decided, hey, this is your body fat, and if you keep lowering calories, I'm gonna keep just reducing your energy expenditure all the way down, right? A great example of that is the Minnesota starvation experiment, right? There weren't any people in that cohort who just didn't lose weight. You know, it's not like they said, wow, you plateaued two weeks into it, and I guess you're not gonna get lean this time. Everybody got lean, right, without exception.

57:33
And so, in a way, it's kind of encouraging to see that type of confirmation that if you are able to, you know, what they did was certainly difficult, but we've seen worse, right? I mean, if you look at a lot of the clinical weight loss literature, you're going to have studies where people say, hey, here's your two protein shakes for the day. You don't eat any food. You just drink these two beverages for the day or maybe three.

58:03
and your total diet is maybe 900 calories, and you're gonna do that for the next however many weeks it takes, right? So we've seen far lower than the 15, 1600 that were being consumed in that study. And that study probably wouldn't have been so bad if it had just been shorter. The problem was it was long for a weight loss study, and when you are that low for that long with caloric intake, you start to get really, really lean.

58:32
And so the unfavorable symptoms that we saw in those study participants, especially the psychological ones, you know, it was really compounded by the fact that once your body fat starting to get very low things, the wheels really fall off. Like at that point, you're not just feeling deprived relative to your baseline, but you're actually starting to.

58:58
reach thresholds of low energy storage that are threatening to your viability. Right? Like you are getting to near starvation levels and it should be of no surprise from an evolutionary perspective that that's where the signals start to really get amplified. When you are at critically low body fat levels, it gets very uncomfortable very quickly, hunger through the roof. You become more irritable, extremely lethargic. You don't sleep well.

59:28
which is really unfortunate. Um, so yeah, I think for, but for the average weight loss, um, application it's worth keeping in mind, you know, a very simple heuristic Minnesota starvation experiment, there were no non-responders not by a long shot. Right. Um, and so sometimes it can be reassuring and kind of boost confidence to lean back on that and say, okay, so if we feel like we're plateaued and we're at a dead end or we're at a brick wall.

59:56
We have to remind ourselves that we just need to make some incremental adjustments and we can always get that ball rolling again. Um, the only time it gets really tricky, um, from a planning or logistical perspective is that very rare application where you've got someone who is small stature, large degree of metabolic adaptation relative to the population average.

01:00:22
And they're doing a physique competition where they are in a competitive category, where they are trying to get as lean as a human can get. In those scenarios, sometimes you do end up in situations where you're like, I really don't feel comfortable telling you to eat less than this, right? You know, you start getting to the point where you're like, I can't tell a person your size to eat less than 1400 calories a day and feel good about it because we got to get nutrients in, right? Um, so, so.

01:00:51
But for the vast majority of, overwhelming majority of weight loss applications, you never get to those uncomfortable trade-offs. It really just comes down to making those incremental adjustments and looking for strategies to facilitate a high level of compliance and adherence to the plan. Yeah. And I think that's the key because it feels like there will be people listening to this and they'll be like...

01:01:19
Come on Eric, I've been on 1200 calories for six months and it doesn't matter what I do, it doesn't matter how much exercise I do or how rigorous and adherent I am to my program, I'm not losing weight. So I'm clearly in this category of metabolic adaptation well beyond what would be expected. Do you ever come across those legitimate cases? Because a lot of people talk like they are that person.

01:01:47
You know, we've never really seen that in the literature, to be completely honest. There's never been like a reliably measured instance of, you know, like just dramatically unusual resistance to weight loss. What we do tend to find in the literature is there's one study that kind of intentionally recruited people who kind of self-reported that they were quite resistant to weight loss and what they found was that they were...

01:02:16
they really dramatically underestimated their caloric intake and they really dramatically overestimated their energy expenditure their physical activity level. And i know that that's a very unsatisfying answer and it starts to feel like people are. Pointing fingers are pushing blame onto the people who are really struggling and i want to clarify that you know that's that's not the intention the intention is always too.

01:02:44
You know before we look for solutions we have to really fully understand the problem that we're trying to address and it. In most cases when someone says why been eating twelve hundred calories for this many months and having lost a pound. You know i mean we can look at the literature and see the. The concert herman published a paper in two thousand twenty one showing total daily energy expenditure in a sample of thousands and thousands of people ranging from newborns to people in their.

01:03:14
late nineties right so we have this understanding of what human energy expenditure looks like. Can we know that you know if you're eating less than your energy expenditure you know you will be in a deficit and that energy is coming from somewhere and it's gonna be coming from store tissues so we can kind of look at the at the math and the documented literature and say it's probably not a metabolism thing here. But what's really tricky is first of all accurately tracking calories is quite difficult.

01:03:43
It is a skill that needs to be built up, no question. And one thing that I can really empathize with is the fact that people seem to differ very considerably in terms of how their appetite is regulated. And specifically, if we look at kind of the neurophysiological elements of appetite regulation, and I think look no further than, you know...

01:04:12
Instances of people who, for example, have maintained at a certain weight, on and without any intention, very comfortably for a long time. Then they go on a medication that impacts some neurotransmitter systems, you know, perhaps like an SSRI or, or some other type of medication. We often see that people will have a change in their dietary habits and a change in their, their appetite regulation and ultimately their body composition when they.

01:04:40
when they go on these new medications that impact their neurophysiological responses to a variety of stimuli. And so I think when we look at folks who really struggle with weight loss, I think the answer is really neurophysiological. And I don't think that people should internalize any of the negative stigma that we attach with high body fat or challenges with losing body fat. And I think the new

01:05:08
class of these newer weight loss drugs that have come along these GLP-1 agonists, I think that they very strongly reinforce that perspective. I think what we see with this new class of drugs is that their impact on the brain is very profound. The neurophysiological regulation of appetite appears to be a massive central mechanism for how they work.

01:05:35
And a lot of people who take these drugs report that for the first time ever they're just not super preoccupied with food all day and they're not hungry all the time. And they don't have these massive reward responses when they have a palatable meal so i always like to address that you as much as people think. That variation in metabolism is underlying their weight loss struggles. In the vast vast majority of instances.

01:06:04
There is, they are struggling with it more than their peers and that's not their fault. Uh, but usually rather than attributing that to differences in metabolism, uh, you know, like metabolic rate or energy expenditure in the vast majority of cases, it's a mixture of needing more proficiency in skills, like physical activity tracking and, uh, energy intake tracking. Combined with. Um,

01:06:33
You know, for some people, those neurophysiological elements, which were they're out of our control for some people, it's just a much bigger uphill battle, um, and I'm very encouraged at seeing what some of these new medications are doing in terms of, um, you know, helping people who have really drawn a difficult hand when it comes to, you know, the neurophysiology of how their appetite is regulated and wired. So, so it's really important to recognize that.

01:07:03
There is a great deal of variation in how two different individuals perceive a weight loss effort. Some people find it way easier to maintain a low body fat than others some people find it way easier to lose ten pounds than others. We shouldn't internalize that or blame ourselves if we're on the end of the spectrum where we gravitate toward a higher body fat level or have. Particularly.

01:07:31
large struggles or challenges when trying to intentionally lose weight. But generally speaking, those challenges have quite little to do with metabolic rate and much more to do with these other kind of factors. And I think people should be encouraged by that actually because if they feel like they've reached the end of the road and they've got nowhere to go, then potentially...

01:07:58
if you're in that boat, seeking the help of a professional that can help you understand better the skill of tracking food, activity, and making sure all of these things are, the boxes are ticked. And also you mentioned the neurophysiology, I think that's what you called it, aspect. But there are dietary things that you can do as you talk about all of the time that helps support that appetite regulation.

01:08:28
You're right, we do have tools. There are tools outside of just diet and exercise that can help support people's efforts, which could absolutely be explored. And I agree that's super interesting, the new GLP-1 agonists in these roles. Yeah, and like you said, I think it can be really encouraging when you sit down with someone. I've had, back when I did a lot more one-on-one coaching, I would do sometimes what I call an energy audit. And I would, you know,

01:08:55
the way that you would do it like with your house if you're trying to test the energy efficiency of your house. But we would really meticulously sit down, I'd say block out 90 minutes, we're going to get on a call and go through the whole day and figure out is it possible that we're less active than we thought or that we're eating more than we thought. And a lot of times it's the usual suspects will find some calories that were hiding from us, you know, things like condiments, sauces.

01:09:22
The big one, honestly, is eating your kids' leftovers, if you're a parent. Like a lot of people, they're like, well, I'm not gonna throw out two and a half chicken nuggets, but where are those chicken nuggets going, right? And if that's happening, you know, two meals a day, six days a week, then now we're talking about real calories. So we'll do the energy audit, and then we'll cross-reference with some of the literature describing, you know, percentiles for, how many calories do humans burn?

01:09:47
like when we measure in massive representative populations what is the actual true. Range that we really see in this data and usually we can work toward a very reassuring conclusion that okay we've been eating more than we thought. We've been burning less than we thought and we're probably within the fairly typical human range of energy expenditure so then what. And that's where we start to talk about various nutrition.

01:10:15
strategies that we can apply that can make things a little bit easier and i just wanna be really clear that the answer is never. I mean i have never given the answer be tougher and do better. That's not what it's about it's not just a simple matter of willpower it's. I like to always put the blame on myself as a coach if i was you know coaching someone. Clearly we have not gone through.

01:10:43
the full list of viable strategies and found the right ones that are most suitable to your preferences. And that is where you really hit the sweet spot is not by hacking someone's been tabloid you know it's nothing like that it's usually figuring out of all the different dietary strategies we could implement to help you. Eat fewer calories on a regular basis in a reasonably enjoyable manner you know.

01:11:12
we need to find the strategy that lines up well with your schedule, your preferences. And once we find that set of strategies, then we are more likely to be on a pretty smooth trajectory. A hundred percent. So basically you're saying it's not just that you're one cold plunge away from your ideal weight. Keep doing what you're doing. Just start the cold plunging. Yeah. And actually, you're going to regret bringing that up because I used to do some, I did a little bit of cold exposure research.

01:11:42
Yeah, so during my PhD, we did a study with brown adipose tissue where we were imaging it. And so to do that, you inject, they call it FDG, fluorodioxide glucose, and you basically apply a cold stimulus. And we were doing some, some PET CT imaging, some MRI imaging. But it was really cool, you know, we'd inject the tracer, we'd basically get people really cold but not cold.

01:12:09
quite to the point of shivering and then see where all these little depots of brown adipose tissue would light up. We did find that obviously energy expenditure would increase during this cold exposure, but we also found two things. First of all, people were miserable. It was so not worth it if you're interested in fat loss. Another thing that you find when you peruse the other literature is that...

01:12:34
When people use cold exposure to induce an increase in energy expenditure, people or animals, we tend to actually compensate, if not overcompensate in terms of later appetite. And that's something that's really unique because that level of compensation or overcompensation does not seem to occur with heat stress. So heat stress actually is probably slightly better.

01:13:02
for actually having a meaningful impact on facilitating an energy deficit than cold exposure. But I wouldn't really recommend either as a meaningfully useful strategy. But yeah, the cold plunge stuff is kind of, it feels terrible when you're doing it. It's not fun. And the literature would suggest it really doesn't pan out for anything related to weight loss. Well, that's interesting. And actually, you've probably just made a bunch of people extremely happy who cannot stand the cold.

01:13:31
Yeah, bloody love this sauna. So that's me. I love my, you know, the reason that I don't like recommend it broadly is just because I feel really uncomfortable about recommending things that even have the potential to be dangerous sauna. I get a little bit nervous about telling people, yeah, lock yourself in a box. That's 180 degrees and come out when you're ready. That makes me really nervous, but I will say I, when I do sauna.

01:13:59
for voluntary high heat exposure, I do notice that it reduces my appetite for a few hours after that exposure. I don't seem to really compensate later in the day. That does seem to be in line with the literature that's available so far. I don't think it really matters, but as someone who enjoys sauna, I consider that to be just a little fringe benefit. Yeah, the ice bath stuff.

01:14:28
Definitely not. I certainly want to consider it to be a viable fat loss strategy. This is great intel, Eric. And what I will end with is, I will say that I love how gracious you were to all the people that you've worked with, that you were looking for opportunities to help them with their weight loss journey better. And it's absolutely not their fault because I get emails from people and...

01:14:55
One in particular springs to mind of a lady who's very cross with me because she did not lose any weight despite following my plan to the letter, to which I then asked her to write down everything she ate and send it through to me. And she responded with, well, I suppose I'm following in the spirit of your weight loss plan. I'm not actually following your weight loss plan. So there is a little bit of human error.

01:15:22
intention or delusion, I think that goes, that occurs with some people. But I like that you didn't even mention that. Yeah. I mean, it's, um, again, you know, like, like I mentioned, I remember this one client who we got to that point where his weight was pretty stubborn and I really didn't feel comfortable telling him to eat less than what he was already prescribed. And I was like, listen, like I, not that I'm, uh, completely

01:15:50
wrapped up in my own ego, but I have to protect my reputation. I was like, I cannot have people out there saying that Eric Trexler told a grown man to eat this many calories. I just can't, I'm, we're at that point for me where we got to, we got to figure out what's going on. And the more we dug into it, it's not that it was his fault. It's just, we, you know, we find out that there's some sauces, some condiments that aren't getting tracked. He usually finishes his son's dinner cause he's a picky eater and had a little kid at home.

01:16:19
And so, you know, we're able to piece it together and figure it out. And I think the signal of a really healthy coach-client relationship is that no one cares about blame. You know, it's not about who did what, point and fingers, all this stuff. It's we both have somewhere that we wanna get together. And if anything, it'd be great if I noticed a mistake I made cause that means I can correct it, right? So we wanna find areas where we can actually intervene and correct things.

01:16:49
It's not about pointing the fingers, it's about saying, fantastic, we just figured out, you know, where we have to focus our efforts. Yeah, no, I love that Eric. And, and thank you so much. Like, I've really enjoyed this conversation, which went absolutely not where I thought it would go. Because I sent you through a whole list of questions and asked one. But hey, that's that absolutely the type of conversation I enjoy I'm having. For people who may not be familiar with

01:17:18
Mass or Iron Culture or anything, can you please just let them know how to find out more from you? Yeah, every week I'm on the Iron Culture podcast. Iron Culture is on all your favorite podcast platforms. That's with Omar Esaf and Dr. Eric Helms. Of course, I'm also a contributor for the Mass Research Review. Every single month we put out a bunch of content related to health, fitness, exercise science, all the good stuff. You can learn more about that at mass

01:17:48
me, Dr. Mike Zordos, Dr. Eric Helms, Dr. Lauren Colenso, Semple, making written content, audio content, video content, like I said, every single month. And then if you want to just stay in touch with me personally, the best way to do that is on Instagram. My handle is at Trexler Fix. Amazing. And of course, I will put links to all of those things in our show notes. Eric, thanks so much for your time this afternoon. Really appreciate it. Yeah, thank you. I really enjoyed it.

01:18:27
Righty, hopefully you enjoyed that as much as I enjoyed chatting to Eric. He's such a wealth of information and I could have been there for hours. So, absolutely check him out on the other podcast, Iron Culture, and also the Mass Research Review, and their journal club actually, which you'll find on YouTube every Thursday, New Zealand time. And it's just a super geeky, engaging opportunity to learn more in the strength, conditioning, and diet space.

01:18:57
I always really love it. Next week on the podcast though I speak to Dr. Terry Boyle on cancer and exercise epidemiology. Until then though you can catch me over on threads, Twitter and Instagram @mikkiwilliden, Facebook @mikkiwillidennutrition or head to my website mikkiwilliden.com and book a one-on-one call with me. Alright team have the best week, see you later.