The Hungry Brain: Stephan Guyenet on Navigating the Complex Relationship Between the Environment, our Habits, and Obesity

You can find Stephen at:
stephanguyenet.org
Twitter @sguyenet

Are you curious about the intricate ties between obesity, our brains, and evolution? This episode promises to satiate that curiosity and deliver insights you can't afford to miss. Our guest, neuroscientist Stephan Guyenet, unravels the complexities of body fatness and its relationship with our brain. Fascinated by the dissonance between our evolved traits and our modern environment, Stefan takes us through a journey of how our ancestors interacted with food and exercise, compared to our current practices.

We dissect the influence of diet and physical activity on body fatness, exploring the connections between calorie-dense, refined foods and increased body fatness. We also delve into how palatability and satiety play significant roles in weight regulation. Stephan enlightens us on the profound impact of our modern lifestyles on our circadian rhythms  and offers tips on how small changes can mitigate any adverse effects. He also shares valuable strategies on navigating food choices.

We touch on the role of non-conscious brain systems in eating and how understanding these systems can help us better navigate our food choices and temptations. Stefan also explains  how different energy substrates impact our satiety levels.

Perhaps our mst important topic, we agree to parter up for a new business venture, The Hadza Cafe! (Joking, maybe...)

Transcript

Jerry Teixeira: 0:00

In this episode, I speak with Stefan Guine. Stefan is a neuroscientist who studies obesity and he also wrote a book called the Hungry Brain. Now the book is a phenomenal deep dive into the neuro-biochemistry of obesity and what drives us to eat. And over the years, I've been involved in some threads on Twitter with Stefan and one of the things that stood out to me is he and I both take a similar view of the current obesity or poor health epidemic and that we both look at it as an evolutionary mismatch between the modern food environment and the environment which we evolve to thrive in. So we do dig into that in this conversation. We talk about Hunter Gather is quite a bit. We even talk about our new joint business venture, the Hodza Cafe, coming soon to a mall near you. So, without further ado, please enjoy my interview with Stefan Guine. All right, stefan, I'm happy to interview you.

Jerry Teixeira: 0:58

I actually read your book recently.

Jerry Teixeira: 0:59

I've followed you on Twitter for a while, been engaged in some online nutrition battles that you've been a part of in the past, and the reason that I was excited to have a chance to interview you is because I think that your work and what you study is probably as important as anything anybody studying in the world today, and that's going to be obesity and nutrition and the reason.

Jerry Teixeira: 1:29

I think people are very well aware we've got an obesity epidemic that is costing billions of life hours, so people's lives are being shortened because of this, but also huge economic hardships, hardships on families, and there's all of these different theories as to why we're in the situation that we're in. But I found your book very interesting and I think that it will help people understand why we've gotten where we've gotten, despite all the knowledge that people would need to combat what's going on. So, basically, I think that knowledge is great, but knowing something and then having a plan to actually institute something effectively are not the same thing. Having support is not the same thing, and I know you're well versed in those areas. So that's my reason for wanting to interview you, and I'm excited for you to be here. But if you could start with explaining how you got into science, what drew you to it initially and how, from there, you got into studying obesity and doing the work that you're doing currently, yeah, so first of all, thanks for having me.

Stephan Guyenet: 2:46

I'm glad to be here. I have been interested in science for as long as I can remember. Even as a young child I was interested in science. I used to read textbooks like for fun when I was a kid. I was a little bit of a weird kid and I decided at a pretty young age that I was particularly interested in neuroscience, and the reason is that it's one of the last remaining great scientific frontiers in biology. So if you look at a tissue like the liver, we still have things to learn about it. But we know a lot more about the liver than we do about the brain. There's just so much left to learn about the brain. It's, I would say, by far the most complex organ in the body and furthermore, it is what makes us who we are right, I mean the essence of being human. A lot of that most of it, I would say, is really about our brains, and so I was very interested in neuroscience and I got my.

Stephan Guyenet: 4:01

I got a degree, my BS, in biochemistry in college with the idea that I would use that as a foundation for neuroscience, and graduates in graduate studies went to the University of Washington and got my PhD there in neuroscience and at the time I didn't really know what I wanted to work on, but I was really interested in neurodegenerative disease and epilepsy. I ended up working on a rare neurodegenerative disease called SCA7 that I used to joke. There's more people studying it than there are who actually have the disease, which I don't think is literally true, but it's probably not that far off. And I mean the idea was to study something that was more broadly relevant to neurodegenerative diseases in general. And you know, I think that makes sense. But on the other hand, I wanted you know, I was kind of chomping on the at the bit to do something that's more directly impactful, and I've always been interested in health and nutrition and fitness, always been very physically active, and so I'm interested.

Stephan Guyenet: 5:12

I've always been interested in body fatness and what determines it, and I realized at a certain point, as I started to learn about neuroscience, that it had a lot to do with body fatness. And you know, the reasons may not be obvious, but if you start to think about it, I think they become obvious. The first reason is that the brain is the organ that generates all of our behavior, and so if you believe that, how much we eat or what we eat or how we move our body has anything to do with body fatness, then you have to believe that the brain is important. And the second thing that is less obvious is that the brain actually contains a regulatory system for body fatness, and we can talk about that more later, but I'll just leave it there for now.

Stephan Guyenet: 6:04

And you know, I started learning all this stuff and kind of was you know, one of the things that struck me about it first of all was that it was really informative. It really kind of helped explain what's going on with with body fatness. And the second part that really struck me was how little this stuff was getting translated to the public in any kind of intelligible way. And so that's what motivated me to write first my blog and then my book to try to bring some of these findings my own research was a small slice of it. Most of you know what I was writing about was other people's research and bring those to the public, and that culminated with my book, the Hungry Brain, and then some, you know, just publish public science communication that I've been doing since then.

Jerry Teixeira: 7:02

So when you first started directing your research into obesity or was it obesity or did you? I mean, what was it that you first? They got you away from studying the rare disorder.

Stephan Guyenet: 7:16

Yeah, sorry I left. I left a piece out of my story, I left a critical piece out. I did my post doc with Mike Schwartz at the University of Washington, studying the neuroscience of obesity. So we were using animal models primarily, with a little bit of work with human tissue as well, to try to figure out what's going wrong with the regulatory system that regulates body fatness.

Jerry Teixeira: 7:40

Yeah, but when you first got into it, I'm sure it intuitively it kind of makes sense because we know, here are our hormones, our testosterone levels, all this other stuff, these things have you have feedback loops, negative feedback loops within the brain. And so you know, like you said, and you're right, and I hadn't thought about it like this, but you are, what's in your brain, I mean, that's the housing, that's you, you know, so inextricably those things have to be linked. I mean intuitively I know you've got to prove it, but intuitively it makes sense Like it is the liver involved, but ultimately it would seem that the brain is, you know, the chief organ responsible.

Stephan Guyenet: 8:18

So yeah, absolutely, and you know there are a lot of things that are regulated by the brain, a lot of things that are regulated by the body in general, and a lot of you know most I'm going to say most. I would have to be certain about this, I'd have to think about it, but I think this is true that when you're talking about most like whole body regulatory processes, I think most of those the brain at least has a hand in, and so it's not surprising that whole body energy status, which is primarily represented by body fatness, would be regulated by the brain. Like the brain has a regulatory system for body temperature, for a really really good one for body temperature, for blood pressure, for all these different variables, and so it's actually really logical that it would have one for body fatness, given its really high level of importance. And actually as early as the 1950s, people already had a sketch of how this negative feedback system works, and we've only flushed it out since then.

Jerry Teixeira: 9:20

So you mentioned 1950, and it wasn't too too far after that where we start to see, well, a couple decades. But you start to see this shift in national, like you mentioned, body fatness. This shift happens which at first I don't think was identified as an epidemic, but in time it turned out that the acceleration continued quick and pace and ultimately spiraled into the obesity epidemic that we're left with today. So when you shifted your research to start studying obesity, initially in an animal model, like you mentioned, at that point had you already started to kind of look into what you thought had caused or what the causes for you and I know it's probably multifactorial. But at that point, when you start getting into this animal research, I'm sure you're thinking outside of that and thinking about humans. So at that point had you formed a hypothesis as to what you thought was responsible yet, or did that come later?

Stephan Guyenet: 10:24

Yeah, I mean I had been thinking about it, certainly thinking about it and writing about it. I think I've refined my ideas over time and I have a little more confidence in my ideas than I used to, not to say that I know exactly what happened that caused the obesity epidemic. We don't have 100 versions of US history that we can run in a randomized way to figure out exactly what caused what. So the best we can do is guess based on things that make the most sense, based on the research we do have. But yeah, I was thinking about it at the time, certainly. I mean, one obvious thing that stands out is that diet has a huge impact on body fatness. So we have these animal models of obesity and it's clear that the most effective way to make a mouse or rat fat is to feed them a fattening diet. There's nothing that you can do other than genetic manipulations. There's nothing in the environment that you can change that is more fattening than certain types of food are. Physical activity does impact it. So if you put a running wheel in their cage, typically they'll use it liberally and that will reduce the amount of fat that they would gain on a fattening diet. And actually, if you give them a healthy diet, they'll stay lean their entire lives, as opposed to slowly, very slowly, gaining weight if you give them a running wheel. So the exercise component does matter in that setting, but the diet is really the main one. Let's see what I was going to say. Lost my train of thought there, but anyway.

Stephan Guyenet: 12:27

Yeah, basically, if you feed them calorie-dense, refined food, they will get fat really fast. And especially, the most fattening thing you can give them is a variety of calorie-dense, tasty human foods. That is literally the most fattening thing you can give to a mouse or rat is calorie-dense, tasty human foods rich in carbohydrate and fat. And the interesting thing you give them one kind of food, like cookies, they'll get fatter. You give them a different kind of food, like salami, they'll get fatter. You give them both and they'll get even fatter. So the variety per se is part of the equation. Basically, if you give them a buffet of really delicious, refined, calorie-dense foods, you can even in the same cage, you can give them unlimited access to healthy, unrefined food. That would keep them relatively healthy and lean for their entire lives, and they will ignore it in favor of eating this buffet of delicious human junk foods. And so I mean to me that's a pretty general conclusion to come to that food has something to do with it, but I think that's an important first step.

Jerry Teixeira: 13:48

Yeah, the thing that's interesting to me when you said that is nutritionists and overall people, as they promote health, recommend eating a wide variety of foods, and obviously they're insinuating you eat a wide variety of quote-unquote healthy foods.

Jerry Teixeira: 14:02

I mean they're not saying, yeah, roll a bunch of junk food in there. But when you look at the research or at least when I've looked at the research on dietary variety, the more varied a diet becomes, the stronger there seems to be a correlation with weight gain, and so that seems to kind of go along with what you're saying. And the corollary of that is the more at least in my experience and with my own diet when you hone in on a group of meals or foods that you enjoy eating, that that support a healthy body weight, and you eat those things frequently, it tends to be easier to regulate your weight. So when I'm preparing food at home and we don't eat out very often, I'm leaner than when we eat out more frequently, and I think that's partly because you need good at restaurant. You got all this great stuff to choose from, so that intuitively, that makes sense. But also, like I mentioned, those data that I've seen where they show that great variety is linked to weight gain. That's actually really interesting.

Stephan Guyenet: 15:02

Yeah, and it's been very clearly demonstrated in animals and in humans. The limited evidence we have supports that as well. I mean, certainly there's no doubt that at a single meal, if you sit somebody down and offer them a wide variety of foods, they'll tend to eat more than if you just offer them a couple foods. And this is anecdotal. But one thing that I find kind of interesting is if you look at the bodybuilder guys, especially when they're going into a cut, they'll often just eat just a few really repetitive, really simple meals. It'll be like rice and chicken and broccoli or something like that, just over and over and over again.

Jerry Teixeira: 15:42

Yeah, totally White potatoes man. I don't know how they do it. That's supposed to be like white fish and potatoes are supposed to be. It's funny because you look, there's research on satiety right, different foods and individually or combined, and then you rate them on how they impact satiety or feelings of fullness, and white fish and potatoes, if I'm not mistaken, are either two of the highest or the highest foods.

Stephan Guyenet: 16:06

Yeah, that's correct.

Jerry Teixeira: 16:08

Right, but I mean, they're pretty boring. I don't know if it's because they are directly stimulating you to not want to eat more or if you're just like dude, I'm over this, I don't want to eat this.

Stephan Guyenet: 16:17

I think it's all part of the same thing. One of the things that we've learned about neuroscience is that everything is connected to everything. So, basically, when the brain is trying to figure out what behavior to generate how much you're going to eat, for example it's going to take a wide variety of things into account on that. It's going to take into account how much food you already have in your digestive tract. It's going to take into account your subjective, how much you enjoy those particular foods. It's going to take into account all this other stuff, like what's going on in your environment.

Stephan Guyenet: 16:58

So I think that, and in that context, what I'm coming around to is that one of the determinants of satiety or fullness that you experience with the food is how good it tastes. So palatability is one of the things that determines satiety, and so I think that is absolutely right. And if you look at these studies that and it's not the only thing, by the way, it's a factor just to clarify but if you look at these studies that feed people a variety of foods and measure how full they feel afterwards, you see a negative correlation with palatability. So, basically, foods that taste really good, your brain is willing to take the breaks off a little bit is kind of the way I think about it Because that food tasting good to you. What that means is that, on an intuitive level, your brain highly values those foods. And when your brain highly values a food, it will often be happy to find ways to allow you to eat more of it.

Jerry Teixeira: 18:03

Now this is kind of interesting because one of the things that I see brought up and I've researched myself and I do find very interesting is the idea of hunter-gatherer populations or pre-industrial populations, and they tend to exhibit robust metabolic health. But part of that is they tend to also have a simplified diet. They may eat a high carbohydrate diet, some are higher in animal foods and it varies across the spectrum depending on where they are, but I'm not aware of any of them where they have this wide variety of ingredients and foods available year-round, and so I wonder how much that plays into their ability to regulate energy homeostasis and their body fatness. I know physical activity they're very active and that plays a role as a protective mechanism, but I wonder how much of it or, if you want to speculate, how much of it do you think is not having access to all the variety that we have?

Stephan Guyenet: 19:05

I think it probably plays a role.

Stephan Guyenet: 19:08

I mean, our eating drive is determined by a lot of things and that's one of them.

Stephan Guyenet: 19:13

So you know, if you look at what hunter-gatherers actually eat and just to emphasize this point that we've left unsaid so far is that this is how humans lived for almost the entire time that humans have existed.

Stephan Guyenet: 19:29

So you could argue that this is more what we're adapted to than the modern world. If you look at what hunter-gatherers actually eat, it's somewhere between tolerable to disgusting to a modern person Like, I think, most people living in the modern world, where we expect basically our palate to be entertained with every meal, would have a really hard time living in this environment. So you know, you talk about the hodza. I think you mentioned the hodza. That's one of the best-studied hunter-gatherer groups. You look at what they eat. First of all, they don't have any salt, no added salt. The only salt they get is from the foods they eat. They don't have fat sitting around that they can add to things. They don't have sugar sitting around that they can add to things. They do eat honey, but they literally just straight up eat it. They don't like sprinkle it on things and make you know, toast with butter and honey, and so that's first of all. And second of all, you look at the foods they eat. Some of them are tasty, so like they eat some nuts that are described as tasting like almonds, like so you could think of unsalted roasted almonds. They have honey, they have certain types of fruits that are probably pretty tasty, but a lot of the other foods that they eat are not that tasty. So you talk about baobab fruit. That's one of their main, that's one of their main calorie sources. It's really fibrous, it's not very sweet, it's kind of tart.

Stephan Guyenet: 21:16

You talk about the tubers they eat. The tubers they eat are so fibrous that they cook these things. They look like long sweet potatoes, at least some of them, and they cook these things and then they chew them and they're so fibrous that they have to spit out this wad of fiber and just kind of like swallow the juice and those are described as not tasting very good. And then the meat they eat. I mean it's meat. I'm sure it tastes fine, but you know they're not eating wagyu beef. It's like super lean muscle tissue that's probably pretty gamey. And how do you cook it? You're not even putting salt on it, you're basically throwing it on the fire, or bearing it next to the fire with coals, scraping off the burn parts, hoping that there's not a lot of raw on the inside, and eating it.

Stephan Guyenet: 22:08

Or you know another example they will fight prides of lions for carcasses that the lions have been chewing on. They will eat meat that's been sitting around that to us would be like hopelessly rotten, like straight up rotten. They will eat, and so, like this is the kind of stuff that I'm talking about, like some of the stuff they eat would be stuff that we could eat and feel okay about, and some of it we would just be like utterly disgusted by, and most of it, I think we would find pretty bland. And that's how humans ate for almost our entire existence. So, yeah, I think that's one reason. I think also, though you know you mentioned the exercise, so there's like the physiological aspects of physical activity, which might help regulate our appetite, might to a small extent increase our metabolic rate, and then, but there's another aspect to it that I think is really important, and that's that the physical activity that they're doing is in service of trying to get food right. I mean, that's basically their full-time job is trying to get food, and so it creates this tremendous effort barrier to obtaining food.

Stephan Guyenet: 23:23

So you know, if you think about like what if the Hadza ate or had access to exact same foods that we do? So on this, you know savanna, there's like pizza, there's ice cream, there's, you know, white bread and bologna sandwiches, there's everything. But they still have to walk eight miles and climb trees and get stung by bees and whatever to get that food. I bet you they wouldn't. I bet you they would not be nearly as fat as most people in affluent countries, simply because there's that enormous effort barrier. So you're not going to casually drink a Pepsi, you're not going to casually reach over and grab, you know, a snack If you have to walk three miles and climb a tree for it. So I think that's part of it is. There's just much more of an effort barrier historically to eating. That has been almost completely removed in the modern world.

Jerry Teixeira: 24:20

Yeah, that makes a lot of sense in light of, you know, technological advances have happened in every aspect of our lives and that just keeps accelerating. And on the one hand we've lost basic, you know, day to day energy expenditure, and it's not not so much just calories burned. But I think people don't realize that movement plays a key role in keeping your body metabolically fit and healthy. Like we didn't evolve to be sedentary, right? So you know, walking your calves are contracting, helping recirculate blood, and in recent research they've even found that if you're sedentary all day but you exercise a 45 minutes, even if you go hard for that 45 minutes, you're probably more likely to get injured if you're sedentary the rest of the day. But from a longevity standpoint, or when I look at all cause mortality, it doesn't really help that much, if at all, depending on the research that you're looking at. And so it's important to recognize that the technological displacement of movement throughout our day, where cultures such as the Haas, other hunter gather societies, they are physically active, and that's one of the arguments I hear is like well, it's not like they go to the gym, they're not running sprints or whatever. No, they're not.

Jerry Teixeira: 25:35

And I think, and my thinking on this has evolved because when I was younger I was more, you know, strength training and some explosive cardio, no low intensity work. But humans have this incredible capacity for endurance and you know we evolve that way. And so when you look at these hunter gather tribes, it's a lot of walking, bending over, picking tubers, gathering food. The Chimani and Bolivia it's rowing boats, walking, you know, vast distances. So I don't think it's about doing all this high intensity exercise Well, that has a specific purpose and it's great. I definitely think that just the displacement of physical activity even if that's not the primary reason that we've gained the weight I think that plays a significant role in the decline of our metabolic health.

Stephan Guyenet: 26:21

Yeah, absolutely. I mean there's no question that physical activity plays a huge role in health and I think you know, I think it could have played a role in the rise in obesity over a long time scale. I think there's a fair amount of disagreement over how much physical activity has changed in the US in more recent years, like since 1980, when obesity rates really have soared. But I mean, if you look over a longer historical timeline, absolutely physical activities have declined a lot. I mean you think about just what it was like to live a normal life 100 years ago where there was no washing machine, there was no clothes dryer, you didn't have a motor vehicle. You know, if you were lucky, maybe you had a horse to ride around to get from place to place. So you know, and many, many, many more people were engaged in physical labor, farming or working in factories and whatever. And actually it's interesting you look at, yeah, something like 70% of people were engaged in physical occupations, like a century ago or something, if I'm remembering the numbers correctly. So there's been absolutely huge changes in occupational physical activity and just total physical activity if we look on it over a long time scale.

Stephan Guyenet: 27:45

And, interestingly, if you look at, you know hunter-gatherer groups like the HADZA. You mentioned that they walk a lot, for example, hadza males if I'm remembering correctly, hadza men they walk about eight miles a day on average and but actually their energy expenditure is lower, or sorry, not their energy expenditure, their physical activity level is lower than subsistence farmers. So if you look at farmers who are working the land to feed themselves and their families and are not doing it in a mechanized way but doing it how we would have done hundreds of years ago, those people work their butts off. I mean, they're working even harder. And that's what we're coming from in the United States as a society. As we went through industrialization, we went from that kind of an agricultural society where most people were growing crops, to one today when most people are not required to do physical activity and whatever physical activity they do is mostly elective. In other words, they do it just to stay fit.

Jerry Teixeira: 29:04

Yeah, my grandparents owned a dairy and so when I was in my younger years, growing up, my dad worked on it, my grandfather worked on it, and they would wake up in the morning, sometimes just coffee, or they'd eat and then go out and they were working for the vast majority of the daylight hours. You know so definitely, I think physical activity in that protective role, you know, even if you are eating hypercaloric, even if you are under that assault of excess energy, when you're also expending more energy, I think that there's probably a I think number one you have the energy balance portion of it. But then you look at it in athletes, right, when you are healthier and you have especially and I don't want to get too technical with it but you have metabolic flexibility in your body. Actually, your mitochondria work better when you're physically active.

Jerry Teixeira: 29:59

Things on a cellular level they just function better, regardless of how you eat, which is why physical activity and one of the things I try to preach on social media is physical activity correlates with improved health outcomes, no matter what your body composition is to a certain point, once you pass I can't remember off the top of my head, but there is a certain level of BMI, a certain level of obesity where, while physical activity still would show positive changes in labs and things like that, it doesn't reduce all cause mortality. So I think that's important and that is protective, but to a point. I mean, at some point you lose that protective ability. But before we move on from the Hodza, so I'm assuming right now you don't want to partner up with me in a Hodza Cafe.

Stephan Guyenet: 30:52

Is that like we make people eat scraped like charred parts off of animal chunks of animal meat that were thrown in the fire?

Jerry Teixeira: 30:59

Yeah, yeah, we can start in a food court somewhere and see how it goes.

Stephan Guyenet: 31:03

Baobab and burned slash raw meat sounds good.

Jerry Teixeira: 31:07

Can I get a side of honey? No, not on the meat. They don't put that on the meat.

Stephan Guyenet: 31:10

Yeah, you just have to drink it straight up. Yeah, just spoonfuls or handfuls rather.

Jerry Teixeira: 31:16

So one other, mentioning Hunter Gathers just as I think, maybe an example of how this plays out the Chamani in Bolivia. If I said that properly recently, I think about the last decade they've had mechanized boats where some of the tribesmen have gotten these mechanized boats and now they travel upstream to cities and the members of the tribe who are on these boats. Now they've gotten access to highly processed foods, the Chamani. For people who don't know or aren't familiar, they have, as far as I'm aware, the lowest atherosclerosis rates in the world and they up until recently where, as domestication or whatever the right term for it is, industrialization has hit members of the tribe. That has changed now. All of a sudden their cholesterol levels are going up and they're starting to have prediabetes in certain tribes members.

Jerry Teixeira: 32:15

And I think it's hard to tease if it's food versus the boat, because the people that this is happening to are the ones that no longer have to row the boats, they're no longer doing the physical activity. So it's almost like they went from this highly active, limited diet, hunter Gathers situation and almost overnight got stuck into something more akin to a Western style processed food or high availability of processed food and then lack of physical activity. So it's just really interesting to see these people. That not over generations, but it was like all of a sudden in a matter of a few years this was introduced for us in America.

Jerry Teixeira: 32:53

It was like this this was building for a while. It wasn't like I understand. You have the obesity epidemic, where it seems like all of a sudden it just took off, but the foundations, it seems, were being put in place with the advance of technology. So it's just, on the one hand, kind of sad to see it happen to these people, because they don't know, they don't understand, and then we bring them oh look, here's technology, here's all this great stuff, and it's like here's a heart attack as well.

Stephan Guyenet: 33:21

Yeah, it's tough. You look at the United States and we have, in some ways, our health is incredible compared to Hunter Gatherers. We've basically conquered this wide variety of infectious diseases. We, on average, we live way longer, we have way less infant mortality, our lives are safer in many ways, but, yeah, we have these new epidemics of cardiovascular disease and type 2 diabetes and certain types of cancers and, of course, obesity very widespread.

Stephan Guyenet: 33:56

As far as the Trimani data you mentioned, I haven't seen those specifically, but I mean, that's a story that has happened many times all around the world and this was one of the things that I was really passionate about when I first started getting into this is there are all of these studies of cultures all around the world, non-industrial cultures, documenting incredible metabolic and cardiovascular health and absence of obesity, so entire cultures where you can't identify a single person who has obesity, where you can't identify a single person who has elevated blood glucose levels. You can't identify, you know, people who have cardiovascular abnormalities that suggest that they had previous subclinical heart attacks, which those are very common in populations like Americans or Europeans, and there were actually these huge autopsy studies that were done in Africa and China and the US. So not China, sorry, korea and Japan and the US, where they looked at literally thousands of people's hearts and coronary arteries in different cultures in the 1960s I believe it was and what they show is that there are certain places, the least industrialized places, which were Uganda and Nigeria, if I remember correctly, rural Uganda and Nigeria these people, even at older ages, just simply did not have heart attacks, like there was no evidence that any of them had had a heart attack even at older ages, whereas in populations either you could look at white people or black people in the United States and you would find that like a third of them in the same age categories had either died of a heart attack and that was their cause of death, or they had evidence of a previous non-fatal heart attack that had kind of scarred over. So there's virtually none of that in these populations.

Stephan Guyenet: 36:12

And then if you look at cultures that were kind of that were industrialized but maybe to a lesser degree, like the Korean and Japanese populations, you see lower rates of heart attacks but they still have some. And then in the American populations you see just very, very high rates of heart attacks and they noted that. You know, in conjunction with this lack of heart attacks. These people had less atherosclerosis. They had less buildup of plaque inside their arteries. So, yeah, I think a lot of people aren't aware of how much actual evidence there is on this, that our current, like the way that we currently suffer from high rates of cardiovascular disease and obesity and type 2 diabetes is very, very, very atypical when you're thinking about it in terms of the historical norm, the long-term historical norm for human beings.

Jerry Teixeira: 37:18

Yeah, I think that's what led me initially or kind of helped shape my thinking looking at ancestral populations and not being dogmatic about it, because I think you have the naturalistic fallacy which, for people that are not aware, it's assuming everything's always better, that just because it's the way we've always done it. Obviously it's not necessarily the case, right, but I do think that when you think about it intuitively, you've got I mean billions or hundreds of millions if you go all the way back, but you've got millions of years of evolution and you've got this shaping. You know we evolve in response to our environment. So we've got this long-term subsistence and adaptations to an environment, and then all of a sudden that environment starts to radically change with the Industrial Revolution. And well, I mean you know domestication of light and things like that first, or fire probably, but that was still a very gradual advance. And then all of a sudden you have this, you know, drastic acceleration of the proliferation of technology and changing of our environment. I mean, even in the last, I don't know if it's 15 years or, but you know, people used to have ATV or maybe a few TVs or whatever in the house, but it's like now you've got and they weren't the behemoths. I mean, now you've got 65 inch, 75 inch screens, we've got screens in our pockets, we've got screens in our cars. So I know that the data are very preliminary as far as this goes.

Jerry Teixeira: 38:46

But I also think, you know you have to look at circadian biology, disruption of that stuff. You know, I think people try to make too concrete or, you know, too sweeping of recommendations with some of that stuff. But I do think it makes sense like hey, we're sleeping less than ever, and not just are we sleeping less than ever, we're staying up later than ever, or the cycles are disrupted, like these are conserved mechanisms for millions, many millions of years and all of a sudden we've vastly disrupted those things. So I think it's important for people to think about that, you know, and look at their current environment and hey, what little changes can I make? You know, some people are all red light bulbs in their house and like going super far into it, which is cool, that's what you want to do, but that's not realistic for most people.

Jerry Teixeira: 39:39

I don't do that, but I do think that a lot of this when you just look at it and you look at, even when you look at the longevity studies that they did on long-lived populations around the world, so-called blue zones, and everybody zeros in on diet. It's all I ever seen anybody talk about with blue zones like just plant-based people arguing with. You know, it's all based on what they eat. But when you look at the pillars or the things that are associated with longevity, it's like they live, they feel like they're more and more integrated into their society. You look at their circadian rhythms, they're living more in tune with those things. They walk everywhere. I mean, they hardly drive cars in most of those places.

Jerry Teixeira: 40:21

It's like, yeah, food's a part of it, for sure, and probably a super important part. I'm not downplaying it, I just think that it's what? When we really stop and think and kind of you and I've gone back to this technological advancement, it's like, okay, this is not in line with what we evolved for. How do we kind of I don't know what's like the 20% of the things that I can do to help me mitigate most of the negative impact of the world that we live in? You know, and to me I think that's what I try to help most people shoot toward doing those things because you know you get to the like hardcore biohacking and you're gonna lose almost everyone.

Stephan Guyenet: 41:00

Also probably a lot of it's not effective.

Jerry Teixeira: 41:02

Yeah, yeah, exactly, at a certain point and I think even if something is effective, there's always the point the law of diminishing returns applies.

Jerry Teixeira: 41:09

You know it's the same way with exercise. Like you could be exercising 12 hours a week and it's probably minimally more effective or potentially maybe even worse, or you know, depending on the data you look at. But you can get the lion's share of the benefits from a small amount of effort. In fact, if you go from sedentary to lightly physically active, there are, I think you net like 50% of the total reductions in all cause mortality. So just getting up and moving around without structured exercise is being lightly physically active as like massively important. So I think it's. You know, if you're somebody that's constantly stand up till one in the morning and sleep in five, six hours, if you just improve that a little bit and cut the lights off a little earlier, get an extra half an hour of sleep, doing it's a small things like that consistently, you're probably getting most of the benefits. Like I see people taping their mouth shut and all this elaborate sleep hygiene.

Jerry Teixeira: 42:02

Yeah, I don't know if you've seen you probably seen that?

Stephan Guyenet: 42:05

No, I haven't seen that.

Jerry Teixeira: 42:06

No, yeah there's like the bio hackers that they start getting ready for bed an hour before they go to sleep. Oh, geez, and it's like mouth tape and like all this crazy stuff.

Stephan Guyenet: 42:16

So it seems psychologically unhealthy.

Jerry Teixeira: 42:19

Yeah.

Stephan Guyenet: 42:19

I'm just gonna say that the funny thing is stress.

Jerry Teixeira: 42:24

I see it with diet or with exercise. I haven't learned as I've gotten older to, you know, do the best you can within reason and then try not to let it consume you. You know some people and I'm super interested in what we can do to impact longevity. I've got kids and want to be around for them, so like I'm highly interested in all this stuff. But there's lots of, you know, recommendations I see floating around.

Jerry Teixeira: 42:48

I'm like I don't do a lot of that stuff just because I think that it's probably not making a big impact. But even on top of that, what's the opportunity cost? You know, if you're like spending three or four hours a day online just reading in circles about nutrition and about all this like it's cool if it's your hobby I mean health is a hobby is great. But it's like your kids are getting older, your wife is, you're getting like, at some point, how many hours did you invest in researching and and I know I get everyone puts time into hobbies, so I'm not knocking it, I'm just saying that and I was guilty this myself in the past At some point you're taking hours away from living to focus on living better and there's a trade-off. You have to do that.

Stephan Guyenet: 43:29

But at some point like Well, I think the other thing is at what point does it become psychologically unhealthy, like? At what point are you actually just obsessing over it and creating fear for yourself? I think that's another question, because I think this is something that is actually pretty common, especially with people around dieting and weight loss, like people will kind of become obsessed with it and it will consume their life and create a lot of kind of unhealthy thought patterns and behavior patterns for them and sometimes create roadblocks with relationships. So, yeah, I think there's that side of it too. Is that, if taken too far for and, by the way, I think it's totally healthy for people to think about nutrition and modify their diet for health I think that's totally psychologically healthy. I'm not saying that that is a bad thing to do. All I'm saying is that can be taken too far and particularly people who have a certain kind of obsessive or worrying personality I think can be susceptible to being psychologically harmed from it.

Jerry Teixeira: 44:43

Yeah, and the societies that are not obese and are healthy. They're not thinking about not being obese, they're not even thinking about being healthy, they just, interestingly, they're just existing in the environment around them and going through life and prospering. In America and a lot of countries in the West or countries that have had this technological advancements, post-industrialized countries we're just going through life the same way that these other populations are just going through life, yet were metabolically sick or overweight. So to me, that's the thing. In my younger years, coming out of the military, I was super lean. I ended up ultimately becoming obese myself and having to fight that.

Jerry Teixeira: 45:29

But during that transition period I thought, like a lot of people well, you just got to eat less, you just got to move more. You're just lazy, you know, to your fault, you're fat. Sorry, you know, I had this and that's kind of what my mentality was, which I'm ashamed to admit that now, which is probably why fate made me fat. But the reason I mentioned that is it's you know, people today like we're waking up, we're taking care of our families, we're doing our jobs, we're doing the same things that we did 50 years ago, like people weren't special back then, they weren't like getting off work and rolling over to the gym and going and running marathons and stuff. I mean, you know a few people.

Jerry Teixeira: 46:06

But I realized like no, it's not a moral failing that we're overweight, it's not, it's not. You know, in a way it's not a fault that we're obese as a population or that we're unhealthy as a population. It's like we're just a species existing in the environment, just like in your labs. When you give the mice an obesogenic environment. It's not their fault. They're just being mice, they're just trying to live and so you know, that's kind of where we're at.

Jerry Teixeira: 46:36

And so when people are overweight or they're not happy with their health or whatever the case is like to me it's I realized it's not really their fault. Yes, they're they. No one can take action for them, Like they've got to. They've got to figure out how to navigate this environment that we're stuck in, which can be, I mean, the biggest battle of some people's lives. So, with being a neuroscientist and with the research you've done and we've talked about how these populations who don't live in our environment, so now, with us being stuck in the environment that we're in, with all these you know traps around us, what are the like what, what, what are the mechanisms that we need to understand, like what drives us to to respond the way we do to this environment? And then, in your experience, what can we do to navigate this environment successfully?

Stephan Guyenet: 47:33

Yeah. So the first thing I want people to really understand is that a lot of the brain activity that underlies our eating behavior is not under our conscious control and is is not conscious in the sense that we can't even really observe what it's doing. So there's a lot of non-conscious brain activity that goes into influencing our eating behavior I won't say determining, because we do have conscious control, but strongly influencing our eating behavior. So if you think about to illustrate this If you think about when you feel hungry, did you decide that you wanted to feel hungry and then generate that feeling, or is it just something that arose from parts of your brain that are outside of your control? It's the latter, and there's a whole system that is there to decide whether you feel hungry or not, and you're not the one who turns it on. You're not the one who turns it off. It just turns on and turns off when it's received certain signals from the body and from the environment. Do you decide when you want to feel a craving? When you smell the smell of brownies wafting out of the oven, do you say, okay, I think I'll start having a craving now to eat those brownies? No, that is a conditioned reaction that your brain produces in response to that sensory cue the smell of the brownies and again, there's a whole brain system that regulates that process, and it's not under your conscious control, and the only part of it that you're consciously aware of is that final end product of all that computation, which is feeling the craving, and so there's a lot of things like this. That's just two examples of non-conscious brain systems that impact our eating behavior, and that's what my book is all about.

Stephan Guyenet: 49:34

Basically, the main thesis is that we have all these non-conscious systems in our brain that are guiding our eating behavior, and the book explains how they are, how they work and how we can work with them, and so I'll talk about a couple of these just really briefly to answer the second part of your question. One of them is the satiety system, which is found primarily in the brain stem, which is the oldest part of the brain that connects the brain to the brain stem, and that is a part of the brain. At least part of the brain stem is dedicated to receiving signals from your digestive tract that tell the brain how much and what kind of food you've been eating, and so you eat food. It goes into your mouth and your stomach and your small intestine, and there's all these signals coming up through your nerves and through hormones that are converging on the brain stem to tell it the nutritional composition of what you ate. And basically what happens is, as you continue to take bites of whatever you're eating at a meal, those signals going up to your brain they build up, and they build up and they build up until your brain stem says, hey, I think we've had enough here, and then you feel full.

Stephan Guyenet: 51:00

People tend to assume that the feeling of fullness is basically their stomach filling up, like there's no more room in my stomach. But in fact, your stomach can hold, usually like twice as much at least as what your typical meal would be. The human stomach is huge and so it's not literally filling up most of the time. Usually, what's happening is your brain has just decided well, that's all we needed. So I'm going to generate this feeling of fullness that makes your stomach feel full, it makes you lose interest in food, it makes you, you know, maybe get more interested in doing something else, pushing away from the table, and. But the interesting thing about this that we can exploit is that this feeling of fullness is not very well, it's not very tightly correlated to the number of calories that's in the food that you're eating. So certain types of food can trigger more or less of a feeling of fullness per unit calorie that they deliver, and so you see that foods with higher calorie density so in other words more calories per gram or per volume those foods are less filling per calorie. So if you think about, for example, the difference between crackers and a bowl of oatmeal, the oatmeal is mostly water and so that has a lower calorie density and it's going to fill up your stomach more per unit calorie. Or fresh meat versus jerky similar situation you're going to feel more full with the fresh meat than the jerky per calorie that you consume. So you have to eat more calories to feel the same fullness, and so higher fiber creates more fullness per calorie, higher protein creates more fullness per calorie and lower palatability creates more fullness per calorie.

Stephan Guyenet: 53:00

We talked about that a little bit in the context of the potatoes and the whitefish. So if so, I mean you add this all together and it's like what is a food? What do foods look like that are higher calorie density, lower in protein, low in fiber and highly palatable? That describes junk food basically like candy bars, pizza, ice cream, soda, like this is. It kind of makes sense when you add it all together and then you look at the opposite of that and you see the things that are high satiety per calorie and they're more unrefined, ancestral types of foods like fresh fruit, fish, meat, eggs, root vegetables, whole grains, things like that that most people would intuitively recognize as healthy. So I think it kind of adds up to something that makes sense, and so that's that system.

Stephan Guyenet: 54:00

And then another system is the reward system, which is the part of our brain that revolves around a part of the brain called the basal ganglia and that regulates our learning and motivation and pleasure around certain basic goals. So it's like you're kind of like gut feelings of craving things like food or sex or other kind of basic. You know human cravings and the pleasure that's associated with those, as well as the way that we can learn to be motivated by being exposed to certain things. And so that system basically it's kind of similar in that your gut sends a signal to your brain but instead of going to your brainstem and causing you to feel full, it causes dopamine to be released in your basal ganglia and that causes you, for certain types of foods that are high in fat, high in carbohydrate. Particularly the combination of carbs and fat together and certain other properties, causes you to become highly motivated to eat those foods and to crave them in the future, so that dopamine motivates you to go after those foods that your brain is wired to prefer, and it also causes you to learn sensory cues that are associated with that. So if you eat brownies, you know 10 times as a kid, your brain's going to stamp in the smell of those brownies and as soon as it smells that smell, it knows immediately that there's an opportunity to get this calorie dense food rich in carbohydrate and fat, and so it's going to get the dopamine spiking. It's going to generate that motivational state that we recognize as a craving, and at that point you might have a hard time controlling your eating behavior once that is activated. And so that's another system that I think is really relevant, and I think a key way to regulate that system is to control your food environment Because, as I described, the thing that activates it is food cues.

Stephan Guyenet: 56:21

So the smell of things, the sight of things, the, even a location, a scenario that has been associated with certain types of food repeatedly in the past. Those are all things that will start getting your dopamine spiking and will get a craving going. So you know, just an example, like if you always have an alcoholic drink in a certain situation, like a certain friend you know an old friend or a certain like holiday party or something your brain remembers that and when you go into that situation you might develop a craving to have alcohol in that situation. So the same kind of idea. So if you can control your food environment so that food cues are not, you're not interacting with food cues throughout the day, you're not providing the trigger that activates those systems and activates the craving that then could be that then you might have to wrestle with and so making sure that your food environment, to the extent that you can, at home and at work, doesn't have food cues, except at times where you want to eat, like mealtimes.

Jerry Teixeira: 57:35

And that actually, I think is really important because, like we talked about, we're just responding to the environment around us, and so I've had people where I've advised them. You know, hey look, you work in an office. The break room is an absolute disaster for most people that work in office. I've worked in finance. At one point I've worked in construction management and, like you, go in there to get water because there's like the water cooler and there's just all this crap from Costco and doughnuts and all kinds of stuff.

Jerry Teixeira: 58:05

Pizza, yeah, yeah you're like well, I'm not even hungry, but those muffins, you know. So I definitely agree, and the hard part, I think, for a lot of people is that, for better for worse, humans are social creatures, right, and I think that that probably played a very important role in our evolution food sharing and making sure that members of our tribe didn't go without.

Stephan Guyenet: 58:27

Yeah, and it's a way for people to show that they care about others. So it's yeah, it's a tough situation.

Jerry Teixeira: 58:34

Yeah, I often advise people if you frequent certain restaurants. So, like you know, I mean I, this is what I do myself. So my wife, she actually eats well. I mean she's not, but she's, her family is genetically thin Like they. Even when they didn't eat well, or, you know, in her past she still wasn't overweight, so she got lucky in that regard. But and I did not have those genes, so we started dating, ultimately got serious and, you know, we started having a family. But when I started eating like her, I started getting, you know, gaining weight and it happened pretty quickly and so I realized, like you know, 50 pounds later, oh, I guess I can't eat like her, you know there is a difference in in you know what the assault one person can withstand versus another.

Jerry Teixeira: 59:25

So what I do now is, you know, like most people, we go to a handful of restaurants or a handful of places, and so I just know when I go somewhere, okay, this is what I, either this or this. When I go to this place, I order a or B, and when I go to that place, I order a or B, and so I just kind of have this and and I'm you know, I when I go to a restaurant, I'm going to spend a lot of money to eat out. I don't want to go order bland, boring food, right, and then pay a ton of money for it. I want to enjoy what I eat. I think you don't.

Jerry Teixeira: 59:56

You don't have to necessarily eat nothing but boring food to to be successful, and you know, stay lean or lose weight. But to your point, I think you do need to have some kind of a plan. And when you're going to avoid temptation, avoid scenarios where temptation is high, to the best of your ability. And if you do get into a situation, a social situation, something like that, if you go into it with a plan, we all, we all fail. But I think if you have, you know these things identified in advance, it makes it a little bit easier. What have you found to be successful? I mean personally, like with you, how do you navigate that, that type of stuff? I'm sure at home you have a certain way that you eat. You kind of feel like, okay, I've got my, I've got my stuff in order. But when you, when you go out with colleagues, when you have things like that come up like what, how do you generally approach that stuff?

Stephan Guyenet: 1:00:50

Yeah. So let me say first of all that I'm not very I don't seem to be very susceptible to obesity. So I've always eaten a pretty healthy diet and especially in the last like since I've been an adult, I've I have tried to eat very healthy and I've been physically active. So I don't know what I would look like if I wasn't doing any of those things, but I think it's pretty clear that I'm not highly susceptible to obesity, like I've never gained a lot of fat, so it's not something that I'm like hyper optimizing for in my own life is just the point I'm trying to make. But I do. I do optimize it to some, to some degree, because I don't I don't think I'm immune. If I look at my family, I'm probably not totally immune, and so I'll just tell you a few things that I do, not just for myself but for my family as well.

Stephan Guyenet: 1:01:46

I control my food environment very rigorously. So the things I was telling you about not having food cues hanging around, I do that. That's one of my main strategies. There's usually there's not a lot that you can just grab and eat in my house at all Like, and if there is something, it's usually something that's got a little effort barrier associated with it. So if you're really hungry, you can peel and eat an orange. If you're really hungry, you can, you know, crack some pistachios. But there's not things that you can just like reach in and grab a handful and stuff in your mouth and anything. Any food that is available is going to require usually some amount of effort. And yeah, like people are kind of like shocked at how little is in my fridge. There's really just like a few staple things, most of which you would have to prepare if you wanted to eat them. I cook all my food, almost all of it from scratch, and I just don't keep things in the house that I'm that I can't control my eating behavior around.

Stephan Guyenet: 1:02:54

And there are things so you know, I you put me in front of pizza and I can just really go crazy ice cream Like. There are things where, like, ice cream is almost drug like for me Like how amazing it tastes, so, but those are just things that I don't keep around the house. But for that reason, and most of the time, most of the time.

Stephan Guyenet: 1:03:17

So you know. Another thing I want to emphasize is that I'm flexible about the way I eat. So I don't I don't really have rigid rules. I know rigid rules can work well for some people. I'm not saying that is not effective or that it doesn't have its place, but that's not how I structure my diet. So for me, like sometimes I do eat foods that I would consider unhealthy, like I'll have. I love to eat pizza, I love to eat ice cream. You know, if it's something that I really enjoy, I'll make exceptions sometimes and and I'll enjoy them.

Stephan Guyenet: 1:03:59

One of my goals for myself is to allow myself and to be able to actually fully enjoy eating foods that I know are unhealthy sometimes. To me, that's a healthy part of my own eating pattern. For me and again, I think there are some people where just complete abstinence from certain foods is the right path. For me, that is the path that is best. Yeah, so those are just some general principles and also so that's the food environment aspect. But the food itself. Usually what I'm cooking is based on unrefined or minimally refined ingredients cooked from scratch. Ie, yeah, a wide variety of things. Omnivorous, it's like omnivorous, whole food based diet. For the most part, I try to keep the calorie density on the lower side. So not a lot of add-fats, not a lot of refined carbs and sweeteners.

Jerry Teixeira: 1:05:12

So that's a general picture.

Jerry Teixeira: 1:05:14

So when you mentioned not having packages to eat, really accessible foods, where they would trigger you or set off a queue, it made me think about, for better or for worse, our society is basically money makes everything go forward. So we're a capitalist country, and so there's a big financial incentive or a big financial reward for food companies that produce food to get you to eat as much food as possible. And so it's almost like because you've got researchers like yourself or other people who are scientists, who are, on the one hand, studying obesity and trying to elucidate why this epidemic's happened, what we can do to protect ourselves against the environment, but then, on the opposite side, you've got literal scientists formulating food to be as uncontrollably edible as possible.

Jerry Teixeira: 1:06:19

So it's almost like on the one hand you've got the good Jedi or whatever. On the other side.

Stephan Guyenet: 1:06:25

You've got the Sith.

Jerry Teixeira: 1:06:28

Like seriously, could you imagine being one? Like, what do you do for a living? Oh, I formulate, for an abyssal. My job is to keep the obesity epidemic going. But I mean, you know your office looks like Mordor. But I think most people don't realize that I didn't think about that, you know, until I got fat myself and had to lose weight and started researching and went down the rabbit hole and started really getting into nutrition and diet and all these things. So when I left the superficial when I was younger, I was like working out to look good, right, I mean, I was in my early 20s and as I got older you start realizing it becomes more about health and taking care of yourself. But when I realized that there's literally teams of scientists who neuroscientists, whatever, who study like how can we formulate this chip to literally be irresistible, like once somebody?

Stephan Guyenet: 1:07:20

eats one.

Jerry Teixeira: 1:07:20

we want them to destroy the entire bag Like they do this. So it kind of. That's the kind of something I realized. I'm like dude, regular Joe, who like, went to the office all day, doesn't stand a chance against a team of scientists that are literally like using your brain against you. So yeah, I think that kind of to your point. You have a set of rules, a set of guidelines that works for you and I've come to realize from early on, thinking like, oh, the problem's carbs, it's all these carbs. And then realizing, well, carbs mostly taste like crap, don't get me wrong gummy bears, whatever, but fruit is, but most carbs.

Stephan Guyenet: 1:07:58

I like how gummy bears are what you're citing as the pinnacle of carb foods.

Jerry Teixeira: 1:08:03

You know what I mean. Like a carb is by itself. I mean it's soda's evil.

Stephan Guyenet: 1:08:07

At least he didn't say candy corn.

Jerry Teixeira: 1:08:09

Oh, the candy corn's terrible, that's not even funny.

Stephan Guyenet: 1:08:11

Anyway, go ahead.

Jerry Teixeira: 1:08:13

I had an argument with my seven-year-old because he was like oh, dad, I like those and I'm like you like these. I'm like how are you my kids? Things are disgusting, you know, you're not my son.

Jerry Teixeira: 1:08:25

But I mean, when you think about I think that's why soda is so bad, or high sugar drinks like that, because I'm partial and thirsty. I would normally drink water, but no, I'm going to drink this. You know, sweet tea or you know which? I would consider sweet tea probably nutritionally a little bit better than a soda, but still not drastically different. You know, they're still both going to be if the sugar content's similar. But outside of drinks, I mean, I was obese. I ate gummy bears. I ate that. I got Skittles. They're good, but I'm not going to eat the king-size bag of Skittles. At some point your teeth start to hurt just too much, you know. But then you, like you mentioned, you take that and you flip it to ice cream. So now we've got a lot of sugar, a lot of carbs, but we've also got a lot of fat and you put those two things together and it's like man, this is like serendipitous. You know this is amazing yeah.

Jerry Teixeira: 1:09:11

So I think you've got to like know yourself, and it takes trial and error, because when I first started out I did the from being, you know, 50 something pounds overweight, just bordering on obesity by BMI scale. I wasn't super muscly at the time, so it was mostly fat. But I started out with a bodybuilding style diet, so it was like chicken and rice, oatmeal, egg whites, and it worked. For a time I lost like 20 something pounds. The problem was the food was so bland it was not sustainable. Like I could not have eaten, like that for the rest of my life.

Jerry Teixeira: 1:09:48

That led me into realizing, like I started gaining weight back, I couldn't handle those meals all the time anymore and that kind of led me into experimentation with, I found, intermittent fasting and ketogenic diet. It's ultimately transition over to more low carb, but I think figuring out the foods for you that help you when you do eat, so when you do sit down to eat a meal, eating a meal that doesn't do satiety so you are full, you know, these days if I eat breakfast I could be too in the afternoon I'm still not very hungry. It's like, oh, I'm vaguely hungry, I should probably eat lunch. You know, I think it's important to find the foods that keep you full for a long enough period to get you through to the next meal and avoid snacking. I know I this is just my personal preference. I understand that there are snacks you can have and at the end of the day, as long as you don't overeat total energy, total calories you're okay, but to me at least, I've found that if I have a snack, I'm just hungry. I don't want a snack, I want a meal. Right, like I kind of look at it like dude, I'm a grown man, like I'm eating, I want to actually eat and I want to feel satiety. So to me snacking does not work. It's a disaster. But again, I know that's not for everybody so I don't want to extrapolate that.

Jerry Teixeira: 1:11:04

But the things that work for me is if I eat a meal it's high protein, or I don't eat it. It's not excessive protein. I mean, I know some people are eating these, you know, two pounds of steak at a time or whatever. So I try to target like 40 to 50 grams of protein three times a day and that's pretty much it. There are times I'll skip the midday meal just because I'm not really that hungry and I'm busy. But I've found that if I stick to three meals a day, if I focus on protein with each of those meals and kind of to your point, I cook all my food. If I'm busy I'll do Greek yogurt with berries and maybe a small amount of nuts or some cacao nibs on it and I'll just you know, literally takes less than one minute to prepare that and it gets the job done. It tastes good.

Jerry Teixeira: 1:11:46

So the thing for me that I think helped me find a sustainable avenue was learning to prepare foods I actually truly enjoy. Like I never eat a meal I don't like. If I don't like it, I might eat it. So if you're and that's what caused me to fail the first time where I did lose the weight and started to come back on is is never. I could kind of white-knuckle it for a time, but getting to a point where I no longer enjoyed eating, it ultimately backfired because I wasn't just going to keep eating the non-enjoyable food forever. It backfired and where I was just like, okay, I can't do this anymore and I went back to almost a sad diet not entirely but and I realized, okay, this is going to get bad quick and so that's just kind of my system, like you said.

Jerry Teixeira: 1:12:30

Similarly, I have young kids and there is some food in my house. That's probably not ideal. I mean, my kids are metabolically healthy, they're active. My daughter was an athlete for 13 years, not anymore. So there are some pitfalls in my house and I do. I've gone to a point now where I can avoid them. Before I would not have been able to. But but yeah, I think that knowing yourself and figuring out how to set your environment up and then how to find meals that for you are not not just eat to satiety, because I challenge anyone to just eat tilapia and and white potatoes right.

Jerry Teixeira: 1:13:07

It's not going to work, you're going to go crazy, so so that's kind of what worked for me. The question I wanted to ask was in a laboratory setting, there seem to be any time they take two diets and they compare them with three diets or whatever the case is, as long as they equate the dietary energy, so the calories in the diet are the same, then what ends up happening is, over the study period, the weight loss is the same. Now, this is this is an in clinic or in the metabolic ward or in a controlled environment. So they know there's nothing else sneaking in. People aren't self reporting to eating food given to them. The weight loss is the same.

Jerry Teixeira: 1:13:45

So I guess, actually in some there's been a few, one I can think of, but there's been some low carb diets or maybe there's a slight metabolic advantage. I don't know how much that even matters or if you, if you know, get your thoughts on that. But but what I'm more wanting to know is in a controlled environment, it doesn't seem like altering macronutrients really matters If the calories are what determines the success when it comes to weight loss. Now, in diets that are not in a controlled setting, higher protein diets oftentimes show an advantage. So in the real world, not in a laboratory setting, what are their general guidelines that you've seen or you believe to be successful when it comes to meal composition? So I don't care if they're plant based or animal based or whatever you know, but when looking at more macronutrient composition, do you, do you think outside of a clinical setting? That makes a big difference?

Stephan Guyenet: 1:14:44

Yeah, I do so if you, so we can start with animal models and then we'll go, we'll move it into humans is if you look at animal models where you can really tightly control the diet. That's the advantage of animal models. You can do really tightly controlled experiments that last a substantial portion of that animals lifespan. What you see is that the most fattening macronutrient composition is lots of fat, lots of carbs and a moderate amount of protein, not high protein, not very low protein. Those both lead to a leaner or phenotype moderate protein and abundant fat and carbohydrate in a calorie dense package. So that's really so. If you look at one study that was done the most comprehensive study that was done on fat versus carb and body fat, and what you see is if you start on a high carb, very high carb, very low fat diet, the mice tend to be pretty lean. You start increasing the fat at the expense of carbs. They get fatter, fatter, fatter, fatter, fatter, until you get up to about 70%, 60%, maybe with 60% fat and you're really starting to slim down that carbohydrate and then they start getting leaner again and so it's basically in the middle part where you've got lots of fat and lots of carbohydrate, where the animals are the fattest, and you see this in human randomized controlled trials too, right? So if you look in the general US public, if you look at average macronutrient intake right now in the US, it's pretty balanced. If you subtract the protein out, the remainder is pretty balanced between carbohydrate and fat. I think probably a little more carbs than fat, but it's pretty close to 50-50. It's in the ballpark of half and half. And then if you look at the studies that have been done where they put people on diets that restrict one or the other, either way you do it, people lose weight. So you can restrict the fat, people will lose weight. You can restrict the carbs, people will lose weight. And so again, I think that's consistent with the idea that in humans too, being in the middle is really the fat, is the most fattening place. So you can either increase protein, just like it works in mice, or you can decrease the carbohydrate, or you can decrease the fat, and those are all scenarios that in the average person will cause weight loss.

Stephan Guyenet: 1:17:32

And it's interesting in mice, you know, I've heard people argue that mice are not good models for human obesity, but there's a lot of things in mice and rats that really parallel humans a lot. Like I said before, if you feed them junk food, they get real fat real fast. If you put them on a ketogenic diet when they have obesity, they will lose weight and they'll get healthier. If you put them on a low-fat diet, they will lose weight, and if you feed them a diet that's a mix of fat and carbs, that's like the fattiest, the most obesity-producing diet. So I think all of that is actually quite consistent with what we see in humans, at least broadly speaking. So, yeah, that's it for macronutrients, and macronutrients is that's one lever. Of course, there are other levers that you can pull to impact body fatness. Macronutrients is one of them. So, yeah, the most fattening place to be is lots of fat plus carbs, moderate protein and I think I was just going to add there's this like eternal debate of does low-carb work better or low-fat work better?

Stephan Guyenet: 1:18:53

And you look at the studies and you know there's been lots of studies done on this and it seems like low-carb causes more weight loss in the like three to six month range. And then you look at it a year and the weight losses are pretty similar after people have started to rebound, and I think you could make the argument that like if you could get people to adhere perfectly, maybe you would actually see better long-term weight loss on low-carb diet. I think that's at least plausible. But the problem is like living in the real world. People just have a hard time sticking to these things in the long run, at least the average person. And again it's like you're saying it's not any cause for blame, it's just the human brain kind of in our environment throwing up roadblocks for us.

Jerry Teixeira: 1:19:51

Yeah, I always tell people that I mean I have been on the lower end of the carbohydrate spectrum. It's like going on 13 years now and that's been from zero-carb experiment to ketogenic, which is, you know, 50 grams of carbs a day, roughly or less up to 125 grams of carbs. I feel good along that whole spectrum. But what I find not difficult to adhere to may be very difficult for someone else to adhere to. So the thing I tell people is a low-carb diet is easy to adhere to for the people for who it's easy to adhere to, right Like a counting calories.

Jerry Teixeira: 1:20:29

Like I know, people get really passionate about counting calories. It's just information, if you like counting calories and that data are meaningful to you and it helps you make better decisions, it's a great thing. So what I always say is counting calories works really well for the person for who it works really well for. If you've got that mindset and you're analytical and you like data awesome there's no reason not to do it right. So the thing that's frustrating on online with nutrition is like people feel very passionate about it, and I totally get it, because we're not healthy. It's impacting society, so we find the thing that works for us and then we get. It's kind of like religion. Maybe you had, you know life wasn't going well for you and then you got saved by whatever religion and it made a big impact in a positive way for you and so you're really passionate about it. So you go like trying to convert everybody and you lose nuance with people and I see that a lot in nutrition where it's like, hey, this is the way, like this is what people should do, and it's true for some people that probably is a great way, but for every person that a specific diet is the way for there's probably five that tried and failed, and so that's where I think like letting people know there's going to be an experimentation period. You're going to need to try different things and figure out what works for you, with an eye on sustainability, because that, to me, that's the biggest thing, like with whatever you try. And to me, the really interesting thing and actually since you're a neuroscientist, I'll bring this up In recent years there's been some studies on ketogenic diets and on beta hydroxybutyrate, which is a ketone body, showing that it reduces appetite.

Jerry Teixeira: 1:22:09

They've done exogenous ketone experiments with it and in my own experience, if I do get into a state of like a pretty deep ketosis, if I'm doing a very low carbohydrate diet, I'm almost I'm not never. I mean, I eat, but I'm rarely hungry Like I have to tell myself oh, it's lunch, I got to make sure I eat something. Or it's dinner, because I also. For some people it's probably fine to skip the meal, but I do also consider my body composition and athletic pursuits and things like that. So I don't want to skip a lot of meals, but in my experience I can focus on eating like a large sweet potato and a big lean piece of steak, or, you know, I can eat higher carb and higher protein and lower fat and I satiated pretty well, like I can do that. I just I have strong cravings for fatty foods. I'm not a sweets person necessarily. I mean I love ice cream, but for most sweets I don't have a deal for me.

Stephan Guyenet: 1:23:04

Got to make an exception for ice cream.

Jerry Teixeira: 1:23:06

Yeah, but I'm dude, like when I was obese, it really wasn't for eating sweets I would lasagna. I will dust the whole tray Like I would just eat and eat. It was crazy how my appetite was voracious. I would amaze my wife even stayed with me. You know, like we would go to dinner. We would go to dinner and we'd order an appetizer and I would eat most of the appetizer, my entire plate. She would eat like half her plate. Pick at the appetizer. I would clean her plate. I would eat so much food. Wow, and it wasn't until later. Going back, I'm like, oh, now I understand. Right, everybody's brain is different, but I kind of get it.

Jerry Teixeira: 1:23:39

I'm like all those foods were like professionally made with the highest possible palatability.

Stephan Guyenet: 1:23:45

And your brain is wired a little different than hers, probably from you know partially genetics and whatever else.

Jerry Teixeira: 1:23:53

So with, but with beta hydroxybutyrate? Have you researched that much with its role in regulating appetite? Like, do you find? I mean, when we're fasting we're like super hungry for a day and a half or so, two days. Then all of a sudden like, oh, I'm not hungry anymore. Yeah, the. Hb levels are vastly elevated.

Stephan Guyenet: 1:24:10

So no, I haven't really looked into this very much. I think it's, I'll tell you. I'll tell you one of the reasons why is because you know exogenous ketones, that you're you're ingesting energy right, and any kind of energy you ingest is going to create some level of satiety. But I think it's hard. You know whether you're you're ingesting fat or protein or glucose or ketones, you're going to get some kind of satiety response. So I think, or whether you're injecting it into the brain. Those are other things that have been done where in, like mice, they'll inject ketones into the brain and show that they eat less. Well, you can do that with glucose too, and you'll see the same thing. So I think it's my question there is is this something unique that's happening with ketones, that's not happening with other energy substrates? And I don't know the answer to that. I'm not saying it's not unique, I just I'm just saying I don't know the answer to that. But I do think.

Stephan Guyenet: 1:25:17

You know, I've eaten a low carbohydrate diet before and it was interesting. I did find it interesting that my eating drive was not as tied to specific meal times so, like when I was low carb, I could skip a meal and it wasn't a big deal I could even. I was fasting more often too. I was fasting once a week for 24 hours and it was not a big deal, right, and when I started eating a high carb diet, again it became a big deal. Skipping a meal I can still skip a meal and I'm okay, but I'll feel it Whereas when I was on a low carb diet it was like no big deal, and fasting for 24 hours, I'm like wrecked now that I'm eating a higher carb diet, so that actually has become a much more big deal.

Stephan Guyenet: 1:26:08

It's funny because physically, my energy level is totally fine. I can work out, I can do whatever I mean. I'm sure if I pushed it hard I would, I would hit a wall, but just normal exercising strength training, totally fine, but I get really bad brain fog is what happens, and so I can't. I can't do it on a work day, I would just be totally ineffective, and so I don't know exactly why. That is physiologically, but the way I think about it this is just me speculating, but the way I think about it is you know, when you're, when you're on a low carb diet, your body's running on fat and so you're withdrawing and depositing into the bank account.

Stephan Guyenet: 1:26:50

That is your body fat. When you eat the meal you're depositing, and then between meals you're withdrawing, and almost all of your energy is just deposits and withdrawal from your, your adipose tissue, your fat tissue. And your fat tissue is huge, right. I mean, even if you're lean, there's a lot of energy in there. You could eat nothing for an entire month and survive even as a lean person. There's so much energy in your fat tissue.

Jerry Teixeira: 1:27:17

Well, there was one guy that fasted. They medically supervised, they fasted him for a year. It's a 600 pound guy, Did you see?

Stephan Guyenet: 1:27:22

Oh yeah, yeah, yeah, it was like a year long fast it's crazy.

Jerry Teixeira: 1:27:25

They gave him essential nutrients, like you know minerals and vitamins and things like that but yeah, no food for a year and the guy lost all the weight.

Stephan Guyenet: 1:27:32

That's crazy. And then, but if you're eating a high carbohydrate diet, a high carb, low fat diet, you're, the bank account that you're depositing and withdrawing from is predominantly glycogen. So you're, you're burning, your body is using glycogen predominantly and when you eat a meal it's replenishing that glycogen, and so you are withdrawing and depositing from body fat, but to a much lesser extent. Your primary withdrawals and deposits are from muscle and liver glycogen, which, by the way sorry for anyone who isn't familiar with that term, that's a. That's your body's carbohydrate store in your muscles and liver, and your glycogen stores are much smaller than your fat stores in terms of their energy content. So you're, you have about two days worth of glycogen in your, in your muscles and liver, whereas you have like 30 days worth of fat and in your adipose.

Stephan Guyenet: 1:28:32

And so you're like, if your body is accustomed to running on carb, you're burning through a lot of that, even just between your meals and while you're sleeping at night. And you're like getting to the point where you you know if you don't eat a meal, you you're going to be digging pretty deep into your body's primary energy reserve. So my way of thinking about it is your body just says hey, our primary energy reserve is is being depleted. I don't want this to happen, so I'm going to motivate you to eat your meal at your you know normal eating time, whereas when you're on a low carb diet, your body's like eh, you know, our total bank account just decreased by 1%. You know who cares, it's not a big deal. You don't have to eat right now, we'll just catch up later. That's kind of how I think about it.

Jerry Teixeira: 1:29:23

Yeah, the trick I think there and I've ran into this with people is if you're going to embark on a ketogenic diet and you think, okay, I'm going to do this, it's really it's important that you maintain those ratios, because you get into a position assuming you stay in ketogenic ratios for multiple days, you get into a point where now you are switched over to burning. You know more of an oxidative metabolism, so you're relying primarily on oxidizing fatty acids at a higher rate than you normally would. So you get into this situation where, like to your point, you maybe have this reduced, maybe you do have a reduced appetite, or whatever the case is, and so, as long as you maintain those ratios, that state continues. So if you're someone who feels great on a low carb diet and you maintain that diet, then you're going to be in that physiological state is going to continue. The problem is, if you're a person who strays a lot, so you're like, cool, I'm keto ratios for two days, but now I'm going to go have this regular meal, it's not that that's necessarily bad. The problem is, whatever the beneficial effect you were getting from that being in that state is going to be disrupted for a certain time period.

Jerry Teixeira: 1:30:40

So the reason I bring this up is if you're eating a high-fat, ketogenic diet and now what I see most often is people that are eating a high-fat, ketogenic diet when they do have, they stray off the. You know, we don't have to call it a cheat meal or whatever it's, just when they eat something that contains carbohydrate, it's usually not like well, I'm on a ketogenic diet, but I just ate a chicken breast and a sweet potato with no butter, right, because we're on a high-fat diet? It's no, I just had my rib eye or whatever, which is fine, but I also had a sweet potato with two tablespoons of butter. So now you had this very high-fat and high-carbohydrate, high-energy meal. So the majority of the times and I'm not the reason I want to be careful with this you don't have to necessarily never mix fat and carbohydrate. I don't want people to be paranoid about, you know, mixing macronutrients.

Jerry Teixeira: 1:31:26

But when the majority of your meals are very low-carbohydrate, high-fat, then all of a sudden you start mixing in some higher-carbohydrate meals. If those meals are higher-carbohydrate and higher-fat, then your dietary energy is going to go up significantly versus that other baseline you're maintaining, and then, whatever the benefits were that you were getting from maintaining a ketogenic state. You're disrupting that and maybe it varies a lot person to person. In my case, maybe due to activity level and I'm not that active, but I mean I do work out daily and you know, maintaining higher muscle mass.

Jerry Teixeira: 1:32:00

I can actually and I've tested with ketone strips, blood ketone strips I can eat 100 grams of carbs in a day and I'll wake up right back in ketosis if I eat them around dinner time. So, like I said, it's all of our physiology a little bit different. What works for us is going to be a little bit different. So I didn't want to scare anybody away from mixing macronutrients, but that's just something to consider. Like in your case, you experience this phenomenon on a low-carbohydrate diet, but that may only apply as long as you maintain the low-carbohydrate diet.

Stephan Guyenet: 1:32:31

Yeah, it's definitely easier to eat a mix of carbs and fat. It's kind of funny the way the brain works. Like you know, I'll look at it from the other side of the spectrum. Something that would be more typical of a meal that I might have. I'll have, you know, on my plate I have some kind of protein and then I have potatoes like just microwave or baked, just plain. I don't usually put anything on them Sometimes. You know, whatever meal I made might have some sauce and I'll put that on the potatoes, but I don't like put butter or cheese or stuff. But if I do, on the occasions every now and then, when I do put butter on the potatoes, not only you know you would think your brain would be like, okay, this calorie-dense substance got added, let's eat less of this, right. But it works the opposite way. Your brain is like let's eat even more, even more than we would have before in terms of volume of, you know, potato plus butter. So your brain is just like this is Awesome, I'm going to crush this.

Jerry Teixeira: 1:33:35

Oh, butter Butter's funny because I mean I do eat it. I'm not just for anybody listening. Like my, my lipids, my blood work is always good, so I don't worry about it. I have kids. I understand that there's different schools of thought toward LDL cholesterol and how much it impacts heart disease. I'm open to wherever the science may happen to lead.

Jerry Teixeira: 1:34:00

I do care what my personally, what my LDL is, and if it were to start to move upward, I would actually make dietary changes, even though there are people that feel very strongly that's not warranted, being that I'm metabolically healthy and all these things. Just because I take a little bit more of a precautionary principle, like yeah, maybe they're right but maybe they're wrong, you know. And if they are wrong and I enjoy my diet anyways, it's not like I'm missing out on anything, so I'm so I just wanted to preface that with you know that's that's just my take on on on, because butter, butter does consistently, across studies, raise LDL. So you know, if you're eating lots of it, that's a side effect you're probably going to run to.

Jerry Teixeira: 1:34:41

But you can add butter to almost any food and it completely transforms the experience, I mean like yeah take a steak and do a butter bath I mean like seared and literally a bath of butter than poor butter. You can't stop eating it. It's ridiculous. You know, I mean assuming you eat steak, but you know, add it to add it to a baked potato, to a sweet potato. Butter and salt on almost anything is like. I mean, I can't even like put into words how delicious food becomes when you, when you start swiping butter.

Stephan Guyenet: 1:35:12

Somebody brought cookies over to my house the other day and I looked at them and I was like these don't look tempting at all. They're like no chocolate chips First of all. They're like the kind of like Christmas cookies with sprinkles and stuff on them. I was like, yeah, this, I'm not even. This doesn't even look worth it. And then and then one day I was like okay, I'm going to take a bite. And I took a bite and it tasted like butter and I ate the rest of the cookie and it was really good. So yeah, it'll do a lot. Butter will do a lot.

Jerry Teixeira: 1:35:46

Yeah, I think dairy like I love dairy man. I'm not mine a lot, you know I eat it regularly. Interestingly, I don't think we have enough data to like clearly tease this all the way out, but I do eat full fat dairy. I don't go crazy, but I'm going to put a little cream in my espresso every day. I melt cheddar on my eggs often and I'm a little. I eat Greek yogurt every day.

Stephan Guyenet: 1:36:13

I'm a little whole dairy doesn't affect your lipids as much as butter.

Jerry Teixeira: 1:36:18

Exactly there's. There's something unique with butter where it does have a different effect, so I do, because of that, use butter a little more sparingly, even when I want. When I'm low carb for anybody that cares when I am low carbohydrate, very low carbohydrate, and I need more dietary energy just because I'm physically active, instead of just throwing more butter on there for fat calories, I'll tend to either go more avocado or I'll use like C8 and CT oil just because it's it's a ketogenic and CT oil and it. I do notice a little mental energy with it, so I'll do that. But yeah, when I was overweight, a baked potato or a sweet potato with butter and salt I literally cannot stop eating like I'm going to eat it until it's gone.

Jerry Teixeira: 1:36:59

So if I bake a big one, I'm toast, you got to bake a small one purpose because you got to go into it knowing okay, I'm not going to stop eating this thing.

Stephan Guyenet: 1:37:08

Yeah, I mean, you could even use cream as an alternative to butter, and it's it's counterintuitive, but from the studies that have been done, it appears that cream does not affect LDL in the same way as butter. Cream is, though, in terms of the flavor, for me is also like crack. I love the taste of cream, so I don't have it very often, but I mean, the other thing to keep in mind is you can just monitor your blood lipids. So if your diet is raising your blood lipids, then it's raising your blood lipids, and if it's not, then you don't have to worry about it. If it is, you can adjust or see a doctor. If it's not, it's not a problem. So you have guys that supposedly, sean Baker's LDL cholesterol is within the healthy range.

Jerry Teixeira: 1:38:02

Yeah, he's posted his blood work before. I mean, unless somebody did an elaborate Photoshop job, it was you know.

Stephan Guyenet: 1:38:08

His blood lipids look pretty good right.

Jerry Teixeira: 1:38:10

Yeah, so I think that's his diet is basically steak and egg.

Stephan Guyenet: 1:38:13

So, yeah, it's like just see what it's like, see what your lipids are like, and if there's no problem, there's no problem. If there is, then you can adjust.

Jerry Teixeira: 1:38:23

Yeah, I think that goes back to, like you mentioned, you've got to experiment and find the strategies for navigating the food environment that work for you, setting your environment up for success. It's to me it's similar with exercise, and the reason that I think a lot of people gravitated toward some of my content is for the last eight years now, I've just worked out at home and I applied, you know, the tried and true basic principles of strength training to calisthenics and you can get great results. It doesn't matter if you lift a weight or if you know barbell, dumbbell, kettlebell, exercise bands or your body. It's all providing tension. Hypertrophy and strength adaptations happen the same way. So for a lot of people and I've ran polls just with my followers or you know something like 60% of people say, oh, I prefer working out at home, but they get this messaging in their head that well, that's not effective. I have people that are like, well, when I really want to get results, I got to start going to the gym.

Stephan Guyenet: 1:39:17

It's like no, you can really get results at home.

Jerry Teixeira: 1:39:19

If you prefer the gym, by all means go like. Find the, find the thing that's sustainable for you. If you're the person that needs to get out of the house and go out of your home environment to work out consistently, then by all means go do that. It's amazing, but for the busy mom or the or you know the guy that's got three kids and the only time you can get it into five in the morning, not having the commute time back and forth can be a lifesaver. So I think it's the same way with diet. It's that there's there's lots of things you can do, and it's going to take an experimentation period to figure out what is sustainable for you. And what works for you may not work for the next person, and too often we we get made to feel like the thing that works for us is wrong.

Jerry Teixeira: 1:40:00

I get people that give me a hard time because they're like oh, I'll post a meal once a month. Say, hey, rate my meal, I'm interested to see what people think, you know. So I'm like hey, go ahead, rate my meal, I can take it, you know. And they're like oh, my God, there's so many oxalates in that. And I'm like I don't eat this every day, Like you know. But there's always a criticism of some type. And I think to your point, like if you're, if your objective health markers are good, on whatever the heck it is, you're eating and you're and you're, you're, your waist and your, your body fat levels are staying in a healthy range, Like if you're healthy and your blood work tells you you're healthy, and I get the argument.

Jerry Teixeira: 1:40:36

There's an argument that well, our population in general is less healthy today. Therefore, the averages in blood work are not ideal, you know which. I understand that because in blood work they're taking like what's normal across at a population level. But what I'm getting at is, for me, my LDL has always been in the 80s. My highest ever reading was 91. It's been in the 70s. I'm comfortable with that, I don't care if it's lower personally. So it's like why, why would I take out foods I enjoy, Dairy, things like that, when I'm uncomfortable to where my blood works at and nobody can make that determination for you. That's something you've got to decide with your doctor.

Jerry Teixeira: 1:41:15

But I think we conflate, like population level recommendations where we think, okay, this is what's probably ideal to recommend at large. We forget that people are individuals. Responses to food are individualized and so the diet that's acceptable for you, based on risk. I mean, you have to try to make that, those types of determinations, but it's going to vary person to person and so you know, if you go on social media and you just start posting what you're eating and what you're doing, you're going to get heat all over the place based on population level recommendations which, by and large, may be good, but those things may not apply to you. So, yeah, I think that's a good point, you good, Okay? So, before we wrap up, because I know your time is valuable, you also are, are you? Did you start Red Pin Reviews?

Stephan Guyenet: 1:42:08

Yeah, yeah, I mean, I started it with the help of other people, but I was the kind of central motivating force. Let's put it that way. I call myself the founder and director.

Jerry Teixeira: 1:42:19

Okay, so what Red Pin Reviews is? It's a website where you can read a review of health diet related books and, you know, hopefully it gets support so that these reviews can happen more frequently. But what you're what you're essentially getting is a review by someone who has a science background of a certain level, who is actually qualified to interpret the data in the book and give you their opinion on it. So do you want to kind of expand on that a little bit so people know what the point of the website is and also if they want to support it? Last I checked, you guys were taking donations and that type of thing, so I definitely want to.

Stephan Guyenet: 1:42:57

Yeah, thanks. So Red Pin Reviews publishes the most informative, consistent and unbiased reviews of popular nutrition books available, and the way we operate is we have a structured expert review method that we apply the same method to each book and it yields numerical scores for scientific accuracy, reference accuracy and healthfulness, and then, if you go visit one of our review pages, at the top of the page you see score bars for those three things as well as an overall score. That's just the average, and so in like five seconds, you can get a really good sense of the information quality of a book. Underneath those score bars you can find our summary of how we scored the book and then underneath that, you can find the full review where we explain exactly how we gave the scores we gave. We have page numbers, quotes, citations to scientific literature. So we're really trying to empower consumers as well as create incentives for authors in the publishing industry to produce higher quality books.

Jerry Teixeira: 1:44:14

And your book is called the Hungry Brain, right? Yeah, so you know I thought it was a great book on audiobook, but people can get that it's available pretty much everywhere, correct?

Stephan Guyenet: 1:44:29

Yeah.

Jerry Teixeira: 1:44:30

And then your website is.

Stephan Guyenet: 1:44:32

My website is stephenginaorg, that's S-T-E-P-H-A-N-G-U-Y-E-N-E-T. I haven't been publishing there much lately, so I'm most active on Twitter and my handle is s-gina, or at s-gina.

Jerry Teixeira: 1:44:52

Yeah, I highly recommend, if people are interested in health, following and you know, I find that following people such as yourself or researchers in the field it's a great way because you will give your opinion and your thoughts on various things, which is awesome. But you tend to get exposed to a lot of new research as it comes out that maybe there's so many publications. Right For a layperson I mean, I consider myself a layperson I love health and fitness nutrition, but I'm certainly not a scientist. There's no way to follow it all. There's no aggregation service. There's nothing that I'm aware of without subscribing to all these different journals.

Jerry Teixeira: 1:45:29

So one of the things I've found very useful is following people like you so that when you guys do share some research in your field, oftentimes you get shared. But the thing that's cool is you guys will share, or you will share maybe, a study and you'll also talk about, hey, a new study on X or Y. I noticed this weakness or there was a flaw. I would have questions about X or Y. So I've learned to kind of what to look for in studies. And again, I'm a layperson, not a scientist. I'm not qualified to, you know, like I'm openly admit, hey, I'm not an expert in this field, but over the years of reading, research and seeing, you know either you or someone like yourself, offer a constructive criticism or question something in a study.

Jerry Teixeira: 1:46:08

it's helped me realize now, when I see a study, I'm like, oh, what about this, what about that? And so I think for people that are interested in getting better at you know, just at a high level understanding when studies come out, where they might have shortfalls following you, following people like yourself, even if they're not necessarily in your diet camp, right, like I follow I actually follow quite a few, even vegan researchers, because I still care what they have to say, even if I'm an omnivore, and I feel that, unless you're going to go through some very elaborate steps dietarily, like most people should be omnivores, right, and I think that's a good question. But I do think following you has helped me learn. So I do appreciate when you do post, when you do give your opinion on things, when you do add color, commentary and things like that or analysis to things that you put out. So I definitely appreciate it. I think people that follow you will find you definitely a worthy follow. I think they'll love the book. Yeah, I'm happy that you were on the podcast, thank you.

Stephan Guyenet: 1:47:08

Yeah, thanks for having me. Well, I follow you on Twitter and I also enjoy your Twitter feed.

Jerry Teixeira: 1:47:14

Oh, I appreciate that.