How Food And Cold Exposure Can Raise Daily Calorie Burn

Thermogenesis is one of the most ignored levers in weight loss and metabolic health, and it changes the way we think about “calories out”. We talk through how your body generates heat all day long, why resting energy expenditure and basal metabolic rate are not fixed, and how small choices can compound into meaningful differences over months.

We start with diet-induced thermogenesis and the thermic effect of food, including why protein burns more energy during digestion and metabolism than carbs or fat. From there, we get practical about preserving lean body mass, because muscle is your primary metabolic machinery. We dig into protein targets, why leucine-rich options like whey protein can support muscle protein synthesis, and how higher-protein strategies may help with weight loss maintenance when the body tries to slow metabolism and ramp up hunger.

Then we zoom out to the environment: brown adipose tissue, cold exposure, and the surprising impact of simply living a little cooler. We also explore emerging ideas on circadian rhythm and blue light timing, including why morning light may support metabolic signalling while blue light at night can push insulin resistance in the wrong direction. Finally, we address a growing concern with GLP-1 medications: rapid weight loss paired with unwanted losses of muscle and bone.

If you care about fat loss without sacrificing strength, function, and health span, hit play. Subscribe, share this with a friend who is stuck on a plateau, and leave a review with your biggest takeaway.

For video and open source references: www.thehealthedgepodcast.com

Transcript

Welcome And Thermogenesis Basics

SPEAKER_01 0:00

Welcome to the Health Edge, translating the science of self-care. I am Mark Pettis with my friend and colleague, John Bagnulo. John, good morning, my friend.

SPEAKER_00 0:09

Hey, good morning, Mark. It's great to see you, buddy.

SPEAKER_01 0:12

Great to see you, as always. We have been talking of late about this interesting topic of thermogenesis, the extent to which our bodies each day will burn calories, generate heat as a consequence of that caloric burn. And so many aspects of our lives are known to affect this energy expenditure, including different degrees of macronutrient mix in the foods that we eat. And I think it's it's a topic that doesn't come up quite as routinely, John. And as as people are very locked into calories in, calories out, and what can I do to enhance the calories I burn beyond what for some is just prohibitive amounts of movement and exercise and intensity. But there are many other ways that we do burn uh calories each day. And understanding this can help someone maybe tailor their uh food, their macronutrient um selections and their activity in a way that can fully leverage this capacity. And so I'm glad so glad that you brought this to my attention, John.

SPEAKER_00 1:41

Well, I think it's just uh an awesome topic because of how it bridges so many different facets of our environment, you know, because we can we can talk about the study that was done at the University of Pennsylvania around 15 to 20 years ago with women. I think they were between the ages of 40 and 60. They turned down the thermostat in their homes from let's just say 72 to 65. And across the board, every every one of the women, I think it was around like an N of 50. So around 50 women, everybody, you know, in the study lost weight, and that was the only change they made.

unknown 2:18

Right?

SPEAKER_00 2:18

They kept everything else the same. So we could talk about the environmental influences on this topic of thermogenesis, which is fascinating, right? We're all, you know, we all have this adaptive mechanism that has over thousands of years has allowed our species to survive in some really hostile, cold, cold climates. So there's that environmental impact that we have really good, you know, more recent observations on how it affects metabolism. Then we have obviously the dietary influences of thermogenesis, which are you can be really profound. Uh, and there's, you know, we can we could break that down into two different ways we look at this, which is you know, how much heat is essentially lost as a part of metabolism, because not every macronutrient generates the same amount of heat for the body as a as a byproduct of just oxidation or producing ATP, right? And then there's the actual thermogenesis, the uncoupling reactions that take place in both muscle as well as brown adipose tissue. And everybody has some brown adipose tissue. Uh, you know, and that that might be new to our listeners, but it's a different type of fat. It's not uh white fat per se, it's this really metabolically active fat whose primary role over the course of human history has been to allow us to survive in these Arctic conditions at times. And there are different, there are different things that influence that type of fat and its activity. But at the end of the day, to your point, Mark, um yeah, calories, you know, calories in versus calories out, a lot of people don't understand how significant the calories out can be with respect to thermogenesis alone. Right? I mean, we have an incredible ability to generate heat depending on the environment that we subject ourselves to and how we eat. And obviously, muscle mass is a big part of that. You're gonna have much, much higher thermogenesis with more lean body mass. But if you put all these things together, it's a great uh introspection here onto human physiology. I I love it. I think it's fascinating because of all the different ways you can go with it and how you can really uh you can compare different ways of eating, different ways of living. And at the end of a month or the end of six months, if you start adding up all of that extra thermogenesis that someone can attain as part of their overall resting energy expenditure, REE, right? Or you know, what a lot of us learned as BMR, the basal metabolic rate, how much we can influence that is profound. So I I love the topic, and I think for people that you know think, well, it's just about how much how much energy or how many calories I can expend when I when I exercise, I think they can, you know, they can appreciate the fact that this at the end of the day, for many people, and I think our listeners will be surprised to hear this, can account for far greater amounts of calories than what you're ever gonna burn, per se, with a walk or a run.

SPEAKER_01 5:32

Yeah, that's that's attention getting for sure. And um, why don't we um uh sort of divide this, John, into the um uh sort of diet-induced thermogenesis focus on sort of food, caloric intake. Um and then and then you you touched on so many incredible uh dimensions of this topic, and then we can focus on some of the non-dietary in a little more detail. And I think one of the things that I think most people are aware of, John, is uh just how universally challenging it is to uh both lose weight and then maintain that weight loss. And one of the reasons, or one of the many reasons that we know that it's so difficult to maintain weight loss is that when we lose weight, when we cut our, let's say we cut our caloric intake and we lose weight as a consequence of that, um our metabolic rate goes down, right? So the body, our design uh which you know evolved in the African savannah, uh and uh obviously there were there were there were predictable times of of deprivation, and uh the body needed a way to defend itself from ongoing weight loss that ultimately could could lead to their inability to survive, right? So uh as we start to lose weight, one way that our that our metabolism protects us is to lower its metabolic rate so that if we continue to struggle to get adequate energy intake, uh we can put the brakes a bit on just how much weight we're losing, because ultimately we start breaking down our muscle, and and that has negative effects. So we have these mechanisms that um can make it difficult for that reason. So why don't we start there, John, uh and and how different uh groups of macronutrients, fat, protein, carbs, have varying effects on this um uh thermogenic effects from metabolizing food, but also might impact significantly one's success with maintenance of weight loss after they've lost weight.

Why Protein Burns More Energy

SPEAKER_00 8:09

Yeah, no, that's I think that's a great place to start. Um, you know, I mentioned earlier that when we talk about the thermic effect of food, how how many calories are released from our body's conversion of food to energy? Now, we could look at that as a waste. Let's just well initially let's just label that wasted energy, right? Because we're not a we don't have a hundred percent efficiency with respect to that conversion. So our the ultimate goal when we metabolize food is to produce ATP. I mean, that's really what we're after. And you know, whether that happens in the, you know, in the cytoplasm via glycolysis of carbohydrates, or that happens in the mitochondria when we oxidize fatty acids or amino acids, because we're not 100% efficient, we're gonna lose some of this energy as heat, as opposed to converting it all to ATP. So, I mean, that's you know, that's I think an important starting point that we could call this initially waste, and I'll we can come back to that a little a little later and say why it's not waste per se. But that that thermogenesis is inadvertent to the metabolism of these macronutrients. And the macronutrient with the greatest amount of let's just call it waste is is protein. So when when amino acids enter, and and I don't want to make this too technical, but we call it the Krebs cycle, right? That's you know what we call oxidative metabolism. So we're oxidizing primarily fatty acids in the mitochondria, but we can oxidize amino acids there as well. And when amino acids get shuttled into the mitochondria and help us generate modest amounts of ATP, you know, less than half of what we'd get from a fatty acid per se. When those amino acids are oxidized, you know, about 40%, 30%, let's we could be conservative, somewhere between 30 and 40 percent of the energy that is generated from again, the conversion of amino acids to energy, 30 to 40% of that is given off as heat. That's the highest. And the benefits of that to the human body, this is why I don't think we should necessarily call it waste, because it, you know, it doesn't really capture its value, is that that spike or that rise in thermogenesis in the body, that thermic effect of food that we get from a high protein meal, that actually stimulates metabolism for the rest of the day. And that's really the you know, the kind of the long-term benefit of that. So high protein breakfasts will set a much higher level of metabolic activity for the remainder of the day. And second would be carbohydrates. Um, but they're, you know, again, they're you're way down. Now you're in the like around 10% of carbohydrate metabolism is given off in the form of heat. And fat actually is only around 5 to 10%. Um, so but again, that doesn't that doesn't give us the entire story, which we'll come back to in a moment. But but protein really gives us the benefits of that high thermic effective food. And of course, it doesn't raise our insulin levels as much as, let's say, a carbohydrate-based meal would, with lower thermic effective food. But the higher insulin response will block fatty acid oxidation later on in the day. So that's why that high protein meal, first meal of the day, achieves two things. I mean, actually, it achieves many more than this. I shouldn't be so reductionistic. It doesn't simply spike our metabolism for the rest of the day and at the same time keep our insulin levels lower. It also helps us maintain lean body mass. You know, the high protein meals typically are going to deliver a much greater amount of micronutrients, you know, depending on what that source of protein is. So it has so many upsides, but the thermic effect of food is by far the most pronounced with a high protein meal compared to a carbohydrate or fat-based meal. Um, but that again, that's just the kind of the start of the conversation here. You know, it's then when you start looking at some of the compounds that might be found in the fat or the fatty acids that could be combined with the high protein meal. Now we get into PAR agonists, right? There are different types of fats that really stimulate PAR activity, which are these peroxisome proliferation activation receptors. I know that's a that's a mouthful, but these are these little receptors on our nucleus. And when certain fatty acids dock in those receptors, it makes that cell, whether it's a muscle cell or it's brown adipose tissue or a brown fat cell, it makes those cells generate more heat, not as a waste or a byproduct of energy metabolism, like we just talked about with protein, but it makes that that cell generate heat as a physiological response to just help warm the body. So that's the difference here. And it's that's why, you know, again, talking about fatty acids, they don't necessarily generate large amounts of heat because of the thermic effect of food when we're converting them to energy. But many fatty acids do have the ability to turn up thermogenesis because of how they influence these P PARs on our the nucleus of all our muscle cells and in within brown adipose tissue. So that's just kind of like a high-level um look at the the different ways we can get thermogenesis, thermo, thermal effects of food. We don't have to call it the thermic effect of food. That TEE is part of a you know overall energy expenditure for any person. But we could just talk about the heat the body generates over the course of a day, and you've got both of those components. You've got you know, the physiological response of the body to certain foods that makes us warmer, make sets us up for more, you know, a better adaptation to a cold environment. And then we have this thermic effect of food, which is just how much heat is lost when we metabolize protein, like you know, as an example. So, but again, I they're very significant amounts of energy. Both of these have the ability to contribute to our energy expenditure at the end of the day. And I think they're really undervalued. And I think you said that at the beginning. I when you introduced this topic, I think you said that, you know, I don't I don't think people really fully appreciate that as much as they should. Uh, I couldn't agree more, Mark. I I think that when I hear people tell me, you know, they're cold all the time, uh, and you probably have heard this too from some of your patients over the years, and you know, you can start thinking about things like thyroid activity. There's a lot of iron status. There are a lot of different, you know, kind of like alarms that go off in a clinician's head when a person is sharing their symptoms with with you and they're telling you how cold they are and how they never adapt to a cold room. But I, you know, I'm at a point now where I often say, okay, well, you know, what do you eat over the course of a day before we do anything else? And what you typically find is that a lot of these individuals have tried these caloric restrictive approaches, and they're really low in protein, and there's probably no protein early in the day, and their body just the engine never starts, right? The engine never starts, it's cold. Um, and I think that a lot of people do so much better metabolically when they start out with that high protein, you know, moderate amount of fat in that first meal of the day.

SPEAKER_01 15:47

Great, John. And we've we've talked so much uh in the past about the importance of minimizing with any weight loss strategy the reduction in muscle mass, lean body mass as a component of that total body weight loss and the importance of more protein beyond the thermogenic effect, you know, to stimulate protein muscle, uh muscle protein synthesis, and the extent to which metabolic health is so tightly connected to lean body mass. Uh the preservation of lean body mass with weight loss uh can kind of keep that engine right running at a at a little bit of a higher uh RPM, if you will. And in terms of insulin and glucose, uh these are very favorable metabolic conditions longer term. So the challenge of rebounding weight and incredible hunger that people experience as they, you know, the body will formidably uh compete with your best intentions. Uh, our biology just wired that way, as we alluded to. So there are just so many interesting attributes of protein as a macronutrient group to sort of offset or at least minimize the extent to which those those issues come up for people.

SPEAKER_00 17:33

Yeah, no, super important to preserve as much lean body mass uh at the end of the day as one can, or gain it ideally. I mean, that's our metabolic machinery, both with respect to this thermogenesis. I mean, yeah, brown adipose tissue is a significant part of it, but it's nothing compared to at the end of the day, the lean body mass that somebody carries. You know, everybody has a small amount of brown adipose tissue, and you know, everything, you know, everything you can do to turn its activity up is is is great, but it's never gonna, it's never gonna match the benefits of of carrying more muscle, greater lean body mass, because that, you know, as metabolic machinery as it goes, it's got that potential to help us with this this you know thermic effect. But then it also, to your point, it's a sponge for glucose, and it's uh it's gonna catabolize so much more energy at the end of the day. And so, what can you do to preserve this metabolic machinery? Um, I would say overall protein should be higher. Uh, you know, again, we you and I have talked about you know the different the different goals. I I usually go now two grams. This is gonna surprise people, but I'm at a point now where I'm you know recommending are like two grams per kilogram, which is almost a gram per pound of body weight for people that are, especially people that are engaged in any strength training, uh, people over the age of 50, you know, you really lose kind of that efficiency with which you can convert dietary protein to muscle and lean body mass. So it seems like every year I'm uh I'm increasing the amount that I recommend for my clients uh a little more than I than I did, and certainly much more than I did, you know, 15 or 20 years ago. And then there are certain types of proteins which are gonna serve someone in this kind of metabolic makeover, this weight loss effort, which is gonna be branched chain amino acids. I mean, I think you could you could you know almost have a mandate for whey protein and other rich sources of branch chain amino acids at least once a day as part of this higher protein approach because of how much better they are at preserving lean body mass, right? I mean, leucine especially the body responds so much, it's just such a much more powerful stimulant of muscle protein synthesis than any other amino acid. So finding ways to incorporate more leucine into the diet, and I think this is where a plant-based diet sometimes can be really challenged with respect to maintaining lean body mass with weight loss. If it's entirely plant-based, typically the leucine levels are much lower. So if someone who wants to be plant-based but is open to maybe adding, you know, this dairy product, whey protein, I think you can, you know, you can really benefit from getting five grams of, let's just say, five grams of leucine, which is a lot of leucine, but I think that's what you would need per meal to compensate for maybe the deficiency of leucine from the rest of those plant-based proteins. You know, 30 to 40 grams of whey protein once or twice a day can go a long ways on top of an otherwise plant-based diet. And then eggs are, of course, a pretty good source of leucine, but nothing is as good as whey protein. It's really the number one source. So, you know, that's an example of a food where you're gonna have greater thermic effect uh at the end of the day, just from the metabolism of that whey protein. Because again, not all, and I think this is important to go back to with our listeners, not all protein that we eat ultimately ends up contributing to our lean body mass. A significant percentage of the protein we eat is going to be oxidized. That's what we started talking about initially. So our bodies are gonna burn some of these, you know, some of these amino acids rather than use that to synthesize new tissue or build muscle. Some of the protein that we eat gets gets oxidized or is burned for energy. And that's where the thermic effect of this of that meal is gonna come from. So we don't, you know, the 30 or 40 grams of protein that I recommend per meal, you know, you might lose 10, you might lose even 15 grams of that to oxidation, which is where you're gonna generate energy. You're gonna get some heat from that, that's gonna help metabolism. So that's why I'm at a point now, Mark, where I'm you know recommending two grams of protein per kilogram of body weight. For most people, because I've started to look at the studies that show, yeah, high thermic effect of food, but it makes me think, wow, like that's how much of the protein is being oxidized for energy, which means that can't be used for synthesizing new muscle. So, you know, I think it's been underappreciated over the years, as have so many things about protein metabolism, which you just alluded to a moment ago. You know, protein metabolism, we have this notion, I think a lot of people do, that we eat protein and the majority of that protein ends up finding a place somewhere in the body as lean as lean body mass. But unfortunately, that's not the case. You know, I guess the silver lining to that inefficiency is that with oxidation, we get this thermic effect of food, which does boost metabolism. But at the same time, I think we need to eat much more protein than a lot of us thought, you know, 20 years ago.

Carbs Fats And Insulin Signals

SPEAKER_01 22:56

Yeah, for sure. I well, that seems a subject in the nutritional scientific community that is still widely debated. Uh, the pendulum has definitely swung considerably in the direction of looking at higher intakes of good quality bioavailable protein, particularly with respect to you mentioned leucine, Joe. We know that there are certain essential amino acids, leucine in particular, that is really the key to turning on that muscle protein synthesis. And some protein sources are simply better for that than others. And we've talked a lot, John, right, about this epidemic of sarcopenia, diminished muscle mass. And it's quite clear as as uh some people get older, uh they become more resistant to uh the anabolic effects of protein. So you generally need a bit more to turn on the protein, the muscle protein synthesis, and of course, uh resistance exercise becomes a critical adjunct to that to allow the muscle to then uh uptake and utilize uh that protein, those amino acids, to uh to fully exert their metabolic effects. How would you guide, let's say, the the carbohydrate uh and the fat principles in in what we're talking about here, John? How would that come into play?

SPEAKER_00 24:38

Yeah, no, it's great. I, you know, there's a different levels of carbohydrate restriction, I think, that can work really well. Um, but I don't think you know someone has to be overly restrictive with the with the quantity. I think if if someone's diet is between 20 and 30 percent carbohydrates, and those carbohydrates are coming from, let's say, resistant starch-rich foods that are slow in terms of their metabolism, they don't spike blood sugar levels. Because again, you know, insulin is the enemy, you know, for so much of what we talk about, but it definitely is when it comes to protein metabolism in this effort to synthesize new proteins. Muscle protein synthesis is a function of different facets of our endocrine system. But insulin, as you know, Mark, it it quickly degrades nitric oxide. You know, that's one of the big problems with this anabolic block that you just mentioned that a lot of older people experience. It comes down to like circulatory issues in essence, right? And if someone is eating carbohydrates that are higher glycemic, refined, you know, spike blood sugar levels rapidly, all of that is very detrimental to endothelial nitric oxide syntase. And so when our nitric oxide levels are being degraded quickly by different facets of our carbohydrates in our diet, then our ability to synthesize muscle protein is compromised significantly. So you really want, you know, again, we talk about the quality of carbohydrates as being so important. You, you know, if you get your carbohydrates from starchy root vegetables and from berries and from things like that, I think that can work out really well if 30 to you know, 35% of calories are coming from those types of foods. Um, I think protein should be a similar amount, like 25% or so, or 30% of calories. So that leaves us with anywhere from 40 to 50% of calories coming from fat. Um, and I think, you know, fat is a, you know, it's a huge part of this conversation, thermogenesis, because while I meant, you know, I mentioned this earlier, we don't generate large amounts of heat from the metabolism of fatty acids. You know, when fatty acids are run through the mitochondria, they don't really generate that much heat compared to protein. But the one thing that fatty acids can do is act as agonists to these pea receptors, and that can really stimulate thermogenesis. And we know that you know fat has so many other qualities that can really facilitate or help someone transition to better health. And you know, olive oil is obviously rich in oleic acid. The body can make this really interesting molecule known as OEA. Um, it's oleanol ethemide, which is uh it's a fatty acid derivative that when it docs in these pea's, it has really potent effects on thermogenesis in muscle and brown adipose tissues. Then there's uh tarostilbean, which is another interesting molecule found in berries. You know, so I'm speaking, I'm just really trying to speak to like some of these qualities, right? We can get from both fat-rich meals as well as from the carbohydrates that might be at me at certain meals. So things like cranberries and blueberries are very rich in this tarot still bean, and that's also a really potent pea par agonist. So that would, you know, again, that would show that there's there are upsides to eating some of these, you know, certain fruits that are low in fructose and are high in some of these pea par agonists. They have the right types of fiber. You know, the obviously the polyphenols are good for gut bacteria. So I always say, like, with carbohydrates, it's not as though everyone has to follow an overly restrictive carbohydrate uh content of their diet, but I think it should be somewhere around 25 to 30 percent of calories from those types of foods, foods that are going to give you some really good kind of broad health-promoting effects, as opposed to you know, your grains and your cereals. They don't really deliver any of that. And they tend to spike blood sugar levels, then you get higher insulin levels, then you have this kind of block you're setting up with muscle protein synthesis. And with fatty acids, I think, you know, whether it's omega-3s from oily fish, those are also omega-3 fatty acids. Your fully elongated, highly polyunsaturated omega-3s are really potent uh peapar agonists as well. So they generate more thermogenesis uh outside of the thermic effect of food. So I think it's good to have whether it's an avocado, whether it's wild salmon, whether it's butter, whether it's extra virgin olive oil, a really good source of fat at every meal that can help also keep this metabolic rate going in the right direction at the end of the day. And I think these really low-fat, high carb diets, to your point, had so many deleterious effects on metabolism. I think the high carb, low protein approach, and I would say, you know, again, they don't have to be, you know, they don't always have to occur like that, but most high carb, low-fat diets are also low in protein, typically when you look at all the studies, right? They're 10% of calories coming from protein. Um, those undermine that metabolic machinery that you spoke of, right? You don't you're not gonna have as much lean body mass after four to six months of a high carb, low-fat diet. Most of those people they might lose weight, but they also lose lean body mass. And so at the end of the day, they're they end up with a much lower metabolic rate. And then they can also end up with issues with insulin levels and things like that. But if you keep the fat present at you know 40, let's just say 40% of calories, maybe 50% of calories, you've got protein at 25% of calories, and then carbohydrates somewhere in that you know, 20 to 30 percent range, you end up with that good mix as long as the qualities of each are there. You know, leucine-rich proteins, um high resistant starch carbohydrates, and then minimally processed uh low omega-6 fats. That tends to equate to the best overall net metabolic effect for a person.

Why Macros Affect Metabolic Slowdown

SPEAKER_01 31:07

That's great, Sean. And we we were looking at a study. I'm gonna just pull this up real quickly.

SPEAKER_00 31:14

Um that's a good one.

GLP-1 Weight Loss And Muscle Risk

SPEAKER_01 31:16

It's the only uh uh slide that um uh we wanted to share. But to the points that that you were just making, John, this was a study done by um uh David Ludwig at the Brigham and Women's Hospital. Uh anyone in the nutrition science uh community knows Dr. Ludwig's work. He's a pediatric endocrinologist uh at the Brigham and uh uh really uh uh develop this uh carb insulin sort of hypothesis of obesity. And uh and again, there the emphasis is more on the hormonal effect of the macronutrient than the sort of caloric content. And um he did a study with young adults, these were adolescent, sort of high school-aged young adults that were all put on a caloric restricted diet. And after losing weight, uh they looked at the body's energy expenditure. So this was just sort of resting energy expenditure, how much are they uh are they burning, if you will, at rest, and then total energy expenditure, which is how much energy the body essentially produces over the course of the day from all things, diet activity, et cetera, and compared those with a low-fat diet to kind of an intermediate uh fat with lower glycemic carbs, and then a very low carbohydrate diet, which tended to be, by default, higher in protein and higher in fat. These were all isocaloric, so the the caloric intake was the same. And as we talked about, when we lose weight, our metabolic rate goes down, right? It's our body's way of protecting itself from excessive loss. And uh so what you see is a pretty substantial drop in total energy expenditure in those on the low-fat, higher carb diet. Uh you know, 420 calories on average per day reduction in their energy expenditure compared to before they lost weight in this clinical trial. When you compare that to a lower carb, higher protein, higher fat macronutrient mix, you really got minimal reduction in uh total energy expenditure. Uh and that these are not trivial differences. This is almost 400 calories a day difference. And so um this is a uh a good example of as you sort of move beyond calorie in, calorie out, uh the macronutrient composition, the quality of the food that you're eating becomes really important in your longer-term metabolic success, uh, all other things being equal as far as the amount of calories that that you're consuming. And that's, I think, uh really important in today's sort of um uh public health messaging, uh, particularly when you look at the uh frustration of successful weight loss maintenance. Uh you see a lot of people on the GLP1s that are losing a lot of weight, but boy, they don't really look healthy.

SPEAKER_00 35:14

Oh, they're losing so much lean body mass.

SPEAKER_01 35:16

And they're you know, they they don't even look like they're stable on their feet when they're walking. There's there's almost a um, for me, it's it's a uh the the the clinical term is caquexia. It's the sort of weight loss that generally you see with with cancer, with things like that. So weight loss is hugely important, but there are consequences of not paying attention to how that weight is being lost and ultimately how you're eating. Because on a GLP1, you can, you know, you don't really have to pay close attention to what you're eating because your appetite is so suppressed. And that's the you know, for the consumer, that's the beauty of these. You could continue to kind of eat what you want, you you just don't eat as much of it. And there's some value there, surely, but um, if you're not paying attention, uh your metabolic health could could deteriorate in a in a very sort of paradoxical way. And as your lean body mass is lost, it can be really hard to reclaim that um over time. And and so uh there are so many shades of gray here, right, John, with the story of messaging, uh and with with what is still ongoing sort of condemnation of fat and protein protein, right? Red meat in particular. So if your if your fear of red meat, fear of fat, beyond what might be your moral ethical concerns about production and how animals, you know, that that's that's another topic. Um but if fear of protein, fear of red meat, fear of fat can be a very dangerous proposition in terms of long-term health, quality of life, health span, and maybe even longevity. Um we've all had a paper, not to dive in too much, but but you know, soon we're gonna revisit an interesting paper that would suggest that fear of sunlight is a very dangerous proposition. Um and I, you know, a lot of people that I am close with fear the sun. And um uh uh so I so I do think there is this, all that we're talking about does require a certain deconstruction of what you've learned, what what you hear, an ability to discern uh in a more sort of prudent way, and a willingness to challenge some of those conventional memes so that you can not only benefit from maybe a drug that you're taking or the strategy that you're adopting, but but have greater longer-term success. It's so much of our lives, it seems, John, and certainly the uh medical research establishment generally tends to focus on shorter-term outcomes and and um which are not often very good surrogates for long-term outcomes. And and I I think that's just an important sort of message, and and uh and a challenge for for all of us that navigating these complex ecosystems, you really uh uh you have to assume that a great deal of what you think is true is not true. Uh and that is not an easy place to go as you want to recalibrate the ways in which you choose uh in a in a modern society which there are so many choices, many of which uh don't serve us as well as we could be served.

SPEAKER_00 38:55

Yeah, there are a lot of barriers to you know people adopting a uh higher protein, higher fat way of life. And I I can't explain the fear around, and not just red meat, the the fear around you know, a gram of protein per pound of body weight for many people that associate that with kidney disease, with osteoporosis. There's just so much misinformation has been put forth around higher protein levels in the diet that I think a lot of people have a certain amount of skepticism that it's going to, you know, that it's it well, I shouldn't say skepticism, fear, I guess, to your point. They have fear around higher levels of dietary protein when, and you know, I know you could speak to this uh better than I. There there isn't there isn't a one published paper that shows protein at that level, you know, two grams, you could go higher than this, uh, you know, causes whether it's kidney disease, bone loss, you name it, right? It's by and large, higher protein levels are shown to be protective, if anything, if there is a statistical difference between the higher protein level and the standard American diet. So I, you know, again, I'm always at a loss for where some of this, you know, where the fear comes for. And again, I'm not I'm not talking about just red meat. I'm just talking about overall protein level, where whether it's coming from meat, dairy, plant proteins, I you know, I think most people are going to benefit from a higher level than what they eat now. But there's psychologically, there's this resistance to go there because of either what they've been taught or what they've heard over the years, much like the case with fat. You know, so that's that's a big barrier, right, Mark? I mean, that's a big barrier, right?

SPEAKER_01 40:58

And uh yeah, we're not we try not to be dogmatic, and there are many paths from A to B. Um, but from a uh, at least from my perspective, clinically and and public health, um our current demographic is not a uh this is not an 1800 demographic uh where you know there were you know uh uh what we see now is just epidemics of of poor metabolic health. So if that's where you're at, um to be sort of tiptoe around these issues, I think is um causes more harm than good.

SPEAKER_00 41:39

Yeah, absolutely.

SPEAKER_01 41:40

So I do think people need to rethink. Um we didn't we didn't get here by accident. Uh this uh and and and so um being um uh the last place you want to be is at the American uh mean um or the status quo.

SPEAKER_00 42:02

Let's briefly, John, um and Mark, can I just add one thing though? You're just one thing that I've that I've witnessed just in these last couple of years where GLP1 has really taken off to just kind of add to what you mentioned. You know, I I can understand people get to this place of urgency with respect to weight loss, but you know what I fear and what I I feel we're going to see in 10, 15 years from now are the unintended consequences with GLP1 use, which is going to be sarcopenia at unbelievable levels. And you know what the clients, the people that I work with that are using a GLP1 drug and want to try to have a higher level of nourishment while they're using it, what I found is that they can't eat the amount of protein they at least they tell me, look, I just can't eat the amount of protein that they need to preserve the current lean body mass that they have. Yeah. So they end up, without exception, they end up losing significant amounts of muscle mass while they're also losing, you know, body fat. And I think, again, that just speaks to you know the importance of long-term solutions that will support people on every level of their health and that will provide what you and I often talk about as healthy life extension. Not life extension, not weight loss, but healthy life extension. Because the goal at the end of the day is to have a quality of life that, you know, whether it's at age 70 or age 80, it's the quality of life that you can experience as opposed to having sarcopenia and not having functional muscle, enough functional muscle mass, right? To do the things in life you want to do. And at the same time, when you're losing muscle mass, you know, with a GLP one drug, you're gonna be losing bone mass. Those two go hand in hand. So it, you know, again, it I can see. Where someone uses it short term, but we have to really question the long-term consequences of this. And if you can't eat enough protein to preserve lean body mass, then I mean in my opinion, that's a huge red flag with long-term GLP1 use. Yeah. Sorry, sorry to interrupt.

Brown Fat Training With Cold

SPEAKER_01 44:15

I just thank you for that. Um so as we bring this home, John, let's just maybe spend the last few minutes on non food uh induced thermogenesis. Uh you talked about uh cold exposure and the effect on uh brown fat. Um we have we have a lot of we probably have most of our brown fat uh as infants, right? Uh when the environment's cold, an infant can't shiver, brown fat creates that heat as a as a life-sustaining adaptive effect. And um there's been a lot of interest, and as we get older and lose some of those brown fat cells, how can we uh leverage what we know about environmental factors that can induce brown fat and and how we can leverage that uh in our metabolic health, John?

SPEAKER_00 45:13

What how is that? Yeah, it's really it's it's really cool. This this fat isn't where we store energy. This is this is a type of fat, and there's three types of fat you know in the human body. There's brown adipose tissue, which is super metabolically active. All it does is burn energy, right? And then obviously there's white adipose tissue, which is where we store. There is some cool research though that's showing that you can like we call it the browning of white adipose tissue. You can make, you can actually make some of your white fat, which is, you know, again, predominantly where we store energy, but you can make it a little bit more metabolically active. I that's more of a recent discovery in the last decade or so. Because of the PARs that are there, those that's the you know, that's the that's really the communication highway, is these these little receptors on the nucleus of any cell and how they interpret what you're eating with respect to what that cell should do. So there's this browning that's potential. And again, I we there's a lot we don't know about that, but and then there's visceral fat, which is where we you know we store fat. That's probably the most damaging when you store it on organs. But the brown adipose tissue, all these uncoupling, that's all it does is you know, the mitochondria there are just uncoupling and to to generate heat as opposed to to produce ATP, they're just trying to produce heat. And yeah, you're to your point, we know that when any human is born, they might have uh, you know, they might have like whether it's two to three percent of their fat in their body, and it would primarily be like on the forehead, on the shoulders, areas that would be over the course of human history exposed to the cold the most, right? Um, and then for whatever reason, lack of exposure to cold, some of it may be, you know, outside of the environmental stimulus, some of that brown adipose tissue might be lost because it just gets dissipated as as someone grows and they just don't they don't produce anymore. So there's some loss that way as a as a percentage of a person's overall body fat or physiology. But we know that with exposure to cold at any given age, whatever brown adipose tissue we have, it gets more active and it can be in essence trained by this favorable stress, which cold exposure is. Exercise is so supportive of health because of all the adaptive responses to that stress. Exercise is a stress that we give to the body, and all those adaptations, whether it's strength training and building lean body mass, or it's the cardiovascular adaptations to you know to aerobic exercise, it's a favorable stress, and that's what cold exposure can be as well. It can be a favorable stress that makes the body and makes brown adipose tissue more active and keeps more of that engaged on a day-to-day basis. And you know, we uh probably a lot of our listeners have heard about the benefits of cold plunges, which a lot of that's circulatory and anti-inflammatory, but also some of that is just metabolically, it just makes someone more active the rest of the day. Uh, you know, and it so it doesn't have to be a cold plunge. Someone, like I mentioned, the U Penn study where, again, these these women, middle-aged women, just turn the thermostat in their homes down and they had higher metabolic activity, largely because of the way the brown adipose tissue is being just challenged a little bit more on a day-to-day basis. Um, yeah, there's so there's a lot of different ways we can get cold exposure. Um, and it doesn't have to be for you know long, long periods of time, three to five minutes in a in a cold, in a cold tub um or in a cold shower. There's you know there's different different ways you can achieve that. But at the end of the day, it's one more tool that we all have to just kind of make ourselves a little more challenged, place a low level of stress on the body that would, in a way, let's say, replicate what our ancestors 10,000 years ago, right? At that last ice age, that shaped human physiology. And so we have that connection that goes back to that, where brown adipose tissue probably meant, you know, a much higher percentage of humans survived that last ice age.

Morning Blue Light And Fat Cells

SPEAKER_01 49:26

Yeah, that's that's beautiful, John. And uh one last thing that that I've been looking at, um, we talk a lot about the effect of sunlight, so many different uh aspects of human biology, circadian biology. Um there there not too long ago, I saw a paper, and this is something I'll I'll dive in a little bit more deeply, maybe on a future discussion, uh, where fat cells, uh white fat cells have receptors that are very sensitive to uh blue light. By blue light I mean you know frequencies of light that are blue. These are typically 480 nanometers, which is uh a sky blue. Uh we talk a lot about the importance of blue light in the early part of the day that um uh turns on a lot of our um uh biologic clocks and uh enhances metabolic activity. Um it it's it's an adaptation to sort of get us ready for the energy that we'll need for the day ahead, the hunting and gathering and and all that comes with that. Uh and so what some of this research is showing is that blue light in the morning in particular activates these these fat cells to um actually break down. They'll release essential fatty acids into the circulation, which actually stimulate brown fat activity, this thermogenic effect. It it's an attempt to not only enhance beta oxidation of fat as a as a um source of energy, uh ATP, but uh to stimulate brown fat uh it for this thermic effect. And um uh it's another example, an environmental example, how in a modern contemporary context we get so little of that natural 480 nanometer light uh in the morning hours when we would most benefit. So, right, we're not getting that stimulus. Um we're uh flooding our environments with 480 nanometer light after sunset. Uh and so um we we uh we have flipped the uh environmental signaling uh and that effect on fat metabolism and thermogenesis on its head. And so I, you know, I don't I don't know that anyone has been able to yet quantify how large that effect is, but we know that blue light at night, for example, uh will prompt insulin resistance. Your a late a late-day meal will lead to greater excursions of insulin and glucose compared to a comparable meal earlier in the day, and how much of that is being influenced by um muscle activity, thermogenesis, um insulin signaling, I think you know, is still being worked out. But um uh it's like we always come back to at the end of the day, John. We we are in doubt, we come into this existence with the software we need. Um it's all there. Um uh the the challenge now in our modern environments is that most of the software designed to keep us alive and uh to extend our health span is now just completely disrupted. And um we all have our strategies for how to compensate for that, but at the end of the day, if you're really not adapting the environment and all that the environment consists of, right, from the food quality to the light quality to everything else, it it you you start to just see these ongoing uh uh disruptions. And um so uh it's it's a fascinating story uh because it always lends itself to just so many opportunities that if we rethink who we are and how we function in relationship to the environments that we're in, we we it's it's it's easy to look around, right, John, and say, wow, man, you know, most modern humans just don't really have a chance. You come out the other end of our food supply and non-native lighting and conflict and just all of the chaos and mayhem. It's really hard to come out the other end fully leveraging the software that you came into the world with. Um so uh it's easy to forget how powerful and amazing and perfect we all are. Uh uh it it and then once your mindset is I inherited all this stuff, uh uh nothing I can do about it, uh I'm just gonna focus on what I enjoy and call it a day. I mean, that that that's one mindset, and and the consequences of that are you know are out there for all of us to sort of look at and learn from. And so uh while it's not easy, uh that's very different than saying there's no opportunity at all. Uh so yeah, that I just wanted to bring that up.

SPEAKER_00 55:03

It's awesome. It's great. It's a yeah, it's a great summary to put our biology in this in this context. Very foreign landscape for the amazing ability that we have to adapt, but we just are in the wrong environment.

Resources Next Topic And Farewell

SPEAKER_01 55:19

Definitely. Well, great discussion, John. I I always enjoy um uh just sharing uh the passion for these topics and discussions. And I learn a lot every week, and hopefully some of this we can impart on Health Edge listeners who we love and uh are grateful for. Uh I'll I'll make sure that um we have a few papers that I'll put up on our website, some overviews of thermogenesis and um uh as well as um um you know the the recordings will be up there as well. So check out our website, the healthedgepodcast.com. Please check out John's Substack. Uh he in recent weeks he he touched on this topic of thermogenesis. There was some great content there as always, and some great um um recipes for some morning whey protein shakes, some good great ways to start the day with quality protein. Um and uh next week, John, we'll we'll address this uh philosophical question of does fear of sunlight um uh make your mortality more likely? Uh and and uh we'll build on so much of what we talked about in terms of that topic. With a with a paper that's about to be published, a paper that we've reviewed recently, that um better than any, I think that has been published to date quantifies the magnitude of sun deprivation uh relative to getting more sun and uh and choosing between a risk of skin cancer that will rarely affect one's mortality or quality of life, versus premature death from virtually all-cause mortality with worsened health span and definitely worsened metabolic health. So uh we'll look at that trade off in a bit more of a scientific way, uh, particularly as the sun season um approaches, and it can't get here soon enough, right?

SPEAKER_00 57:29

That's for sure.

SPEAKER_01 57:31

John, pleasure as always, my friend. Hey, same here. I love you, man. Love you too, and we will see you next week.

SPEAKER_00 57:39

Take care.