Podcast Transcription: The New Science Of Fat Loss with Dr. Stephan Guyenet

Ted Ryce: Welcome to the Legendary Life podcast. Tune in with millions of listeners around the globe as celebrity fitness trainer Ted Ryce interviews world-renowned experts on the topics of health, fitness, nutrition, longevity, personal development, and more. It’s a fun and enlightening way to learn, and the insights you get here will help you upgrade your health, transform your body and live your best life ever! 

And one of the things I love to do with this show is to bring on people with completely different perspectives and paradigms than what you hear out there in the mainstream media, what you hear from many of the popular podcasters and bloggers and YouTubers, and that’s who I have on today.

His name is Dr. Stephan Guyenet. He is a neurobiologist, an obesity researcher and a health writer whose work ties together the fields of neuroscience, biology, chemistry and nutrition to offer explanations and solutions for our global weight problem. He is also the author of the recently released book, The Hungry Brain: Outsmarting the Instincts that Make us Overeat.

And what I’m calling this episode is “The New Science of Weight Loss”. Now, why am I doing that? Well, think about it like this, if we have more information than ever before in the entire history of the human race, on how to get healthier, how to lose weight, how to beat Type II Diabetes, how to get in shape, but at the same time, we have an obesity epidemic that seems to be getting worse, not better, what is going on there?

And we’re going to get into the wiring of the human brain and why overeating is kind of a natural thing. We’re also going to get into where this wiring comes from and why we’re wired this way. And most importantly, we’re going to get into solutions that you can put into your life to start getting results, because at the end of the day, information is just not enough.

In fact, as I stated earlier, where we’re inundated with information, but we’re not acting on it. And you’re going to start to understand yourself better, your habits and tendencies with food better, and we’re going to finish it up with some solid solutions that you can implement into your life to start taking advantage of all the research that Stephan has done for us.

So that’s all I’ve got to say. This is going to be a game-changer interview, a paradigm-shifting interview. So without further ado, let’s get to The New Science Of Weight Loss with Dr. Stephan Guyenet. Welcome to the Legendary Life podcast.

Stephan Guyenet: Thanks, good to be here, Ted.

Ted Ryce: I feel like this is one of the most important interviews that I will ever do, because you are a neurobiologist but you study obesity. And for someone who is not up on the latest research and may not understand the connection there, can you talk a little bit about what you do and why a neurobiologist would be studying why people get fat?

Stephan Guyenet: Yeah. So I think this is a really great question to start with. And the reason is that I think it’s often not intuitive to people why we would be interested in the neurobiology of eating behavior or obesity. And the more I think about it, the more that strikes me as really surprising that it wouldn’t be kind of the first and most obvious place to look, and for the simple reason that the brain is the organ that generates all of human behavior.

And we know that behavior is the primary contributor to eating. I mean, eating behavior is a behavior so the brain obviously generates that. We know that’s highly related to body fatness, we know that physical activity is a behavior generated by the brain as well.

And we also know—and this is something that’s maybe less commonly known, but it’s known in the research community and research on this is really expanding. But the brain also regulates a lot of physiology. And physiology, just to define that term, that just means the normal functioning of the human body. So pretty much everything that’s happening in your body over the course of normal functioning, we would call physiology.

So the way that your liver is regulating blood glucose, the way that your gut’s regulating satiety, your metabolic rate, how much fat is being released from your fat cells, the levels of glucose and fat in your blood. I mean, all of those things are influenced by the brain and it’s not that hard to imagine why that might be. The brain is the information processing organ of the body.

And so it takes in all of the information from inside your body and from outside your body, and uses that to guide your behavior, which is how your body interacts with the outside world as well as your physiology, which is what’s going on inside your body. So when you think about it in that way, it’s pretty obvious that the brain would play a central role in food intake and body fatness. And so that’s what led to my interest in the neurobiology of obesity.

And my research in that area comes from work at the University of Washington that I did as a postdoc with Mike Schwartz. And so we were using animal models to study the brain circuits that regulate eating behavior and obesity—or excuse me, eating behavior and body fatness, because the brain actually regulates body fatness, which is something we can get into later, if you want, and how those processes change with obesity.

And so one of the things that I felt was really cool was kind of coming to the realization during that work that I was—really, I felt that I was looking in the right place, the brain was really the right organ to be focusing on to understand these things that really have a lot of relevance to human performance and human wellbeing.

Ted Ryce: Absolutely, and 10 years ago, this, I don’t even think would have been a conversation, meaning that people just didn’t think about the brain in that way. And Stephan, we talked briefly before we hopped on, I wanted to study neuroscience, I wanted to go in that route when I was 18. And I remember also taking a biotechnology course in the instructor the course he’s like, “Nah, don’t worry about that neuroscience stuff, that’s  go away. It’s all about genes, gene editing, all the things you were talking about.”

And now it’s like, genes, epigenetics, proteomics, all this stuff, there’s some cool stuff happening. But there is all this other very important and very relevant stuff happening with the brain and how it affects our behavior like you think. And I want to just paint the picture a little bit. Most people think they’re completely autonomous, completely logical.

Can you talk a little bit about most people’s—or the misconceptions that you hear from people versus what’s really going on?

Stephan Guyenet: Yeah, sure. So I think some of this confusion that happens comes from a very simple principle, and that is that we’re only aware of the things that we’re aware of, you know? And so the things that are happening outside of our conscious awareness in the brain, the non-conscious processes are things that we’re not aware of, and so we don’t think they’re affecting us. We don’t realize they’re affecting us in many cases.

It’s really not hard to demonstrate that these things are important. Well, first of all, I’ll just say that neuroscience and psychology research is converging on the fact that most of the processing in the human brain—and I’m talking about the vast majority—is below the level of conscious awareness.

When people hear that sometimes they think of this like Freudian idea that we have all these other personalities and demons and whatever that are kind of lurking down in the unconscious. And that’s why I don’t even use the term unconscious. I use the term “non-conscious” to kind of differentiate it from all that. But I mean, there’s a lot of processing that happens and it’s very easy to demonstrate in a way that people can understand.

I mean, think about your heart rate, that’s something that is influenced by the brain, but you don’t consciously control your heart rate. You don’t have to think about controlling your heart rate. And most of the time, you don’t have to think about controlling your breathing either. You can control your breathing, but most of the time it’s on autopilot, including while you’re sleeping.

There’s so many physiological processes happening in the gut and other parts of the body that are being coordinated at the second to second level by parts of your brain, and you have no conscious awareness of that. And it goes even further too because, you know, if you think about what a craving is, what is the craving, and what is hunger? Those are things that you’re consciously aware of, but you don’t really know where that comes from. I mean, you didn’t cause that to happen, right? That’s just a feeling that arose in your mind that motivated you in a certain way?

Ted Ryce: Absolutely. Why is sugar sweet, right? Why does it taste good? Who made that as a rule, right?

Stephan Guyenet: Exactly. And you can choose to not act on those impulses, but you can’t control those impulses. And you’re not the one that generated those impulses, your conscious mind is not the one that generated those impulses. And so those are just some examples to kind of get people in the right frame of mind about thinking about this, because I think when you make examples like that, it becomes pretty intuitively obvious that, yeah, okay. I guess there is a lot going on that we’re not in direct control of.

And so yeah, the concept that you laid out is exactly right. And that’s the drum I’ve been banging lately is that these non-conscious impulses, these are things that are deeply wired into the human brain, and they’re things that have a very important impact on our behavior. And so understanding what those are and trying to influence them in a way that aligns them with our positive rational conscious goals, like having a healthy diet, having a healthy physical activity pattern, staying lean and healthy. Those, I think, are some pretty productive ways to think about how we can improve our lives.

Ted Ryce: Yeah, absolutely. And you’ve done that beautifully, as far as I’ve read in your new book, The Hungry Brain: Outsmarting the Instincts That Make Us Overeat. It’s such an important, important perspective that is missing out there. In the intro, you talk about a couple different things that I think are—I just think people don’t get this. And I’d love for you to go into it.

And the first thing that stood out was that in 1890, 70% of people in the US had manual labor jobs, and they ate less calories. And another thing that she pointed out is that we often blame the institutions, in this case, like the government, for putting out bad dietary guidelines, but the statistics say that we’re not even following that stuff.

So could you paint the picture of what life was like, in 1890 for US and how it’s changed and why that’s important to being overweight, then maybe we’ll knock down some of those myths, that people keep pointing fingers at institutions and dietary guidelines, but it’s really us, it’s our behavior that we need to be accountable for.

Stephan Guyenet: Yeah, that’s exactly right. So prior to the turn of the 20th Century, this country was a profoundly different place in terms of our diet and lifestyle habits. And I think it’s sometimes difficult for people to appreciate really how much things have changed, because we tend to have a view that’s very focused on our own lives and how they are right now.

And especially those of us who are younger, I’m 36 years old, I was born in 1980. And I mean, most of my life, I don’t feel like our diet and lifestyle has radically shifted since the time that I was a teenager, maybe people who are older feel differently about that. But if you look at the numbers, back in the 1890s, things really were radically different.

And as you said, most jobs were manual labor, and we’re talking about hard manual labor, for to a large extent, you know, working in a factory on an assembly line, putting things together. Actually, I don’t know about assembly lines, specifically. But working in a factory, putting things together, working on farms—farm labor was huge.

If you think about all the labor-saving devices we have today, like dishwashers and clothes washing machines and dryers, and many other things like that. They didn’t have those things, kitchen mixers, I mean, you had to do all that stuff by hand. And so built into the fabric of daily life was a relatively high level of physical activity for most people, unless you were wealthy, then you had help.

And then you were almost just as likely to be overweight that as people are today, but the diet was also profoundly different. And so one of the things you see is that at that point in history, almost all of the food that people ate was food that was prepared at home. So they would go to the grocery store, they would buy single ingredients, typically, and then they would come home and cook it.

And I’m talking about even simple things like bread; some people bought their bread, I think that’s been happening for a long time. But a lot of people were actually making their bread in the United States, at least, the statistics bear that out. And that changed radically, I mean, really, quite gradually. And I think this is why people maybe have a hard time conceptualizing this, as the change was very gradual.

But it ended up being really quite radical to the point where today, we spend about half of our disposable income on food eaten at home, and half eaten away from home. Whereas we used to only spend about 7% of our disposable income eating away from home back in the late 1800s.

And I think that those numbers really don’t even quite convey the magnitude of the change. Because a lot of the food that we eat at home today is actually commercially prepared food, things like frozen pizzas, or fries in a bag, and not necessarily all unhealthy food—I’m giving unhealthy examples, but it’s not necessarily all unhealthy.

But the point is that it’s commercially prepared food, not food that’s been prepared in the home, and a lot of it is unhealthy. But one little asterisk I want to put on this is, in the context of these discussions, we tend to have this vision of our former diet as this, you know, idyllic thing that was more ancestral and more natural. But in the late 1800s, that wasn’t necessarily the case, there was a lot less obesity but people were eating a lot of white flour.

I mean, that was around the peak of white flour consumption in this country. It’s gone down a lot since then. But basically what happened was, we had all these technological innovations throughout the 1800s, where agriculture and transportation and storage had these huge advances that made it much easier to produce white flour and make it available. Whereas that used to be an expensive commodity that only wealthy people could afford.

And so basically, there was still that concept that this white flour is this affluent, delicious food. And so the common person, once it became cheap, started eating huge amounts of it. And it became...

Ted Ryce: I want to be a wealthy person, right?

Stephan Guyenet: Yeah, exactly. And it became one of the cheapest sources of calories too. And so by the late 1800s, especially in communities that didn’t have a lot of money, you had very high consumption of white flour. And that was before they knew about vitamins. And so you had a lot of deficiency diseases, as before they knew about vitamins, before fortification, there were a lot of problems, but obesity was not one of the problems.

And I think that relates to the fact that they were making simple foods at home, and they had high levels of physical activity and their food environment was just very different than ours is now. But another point I want to make from this is that, you know, there are all these claims that refined carbohydrate is the cause of obesity.

And I think, looking back at history—and I’m not saying refined carbohydrate doesn’t contribute to obesity, I think it does. But looking back at history, we can see times when refined carbohydrate was even more prevalent than today and it wasn’t causing obesity epidemic in that context. So at the very minimum, I think what that suggests is that it’s a little more complicated than that.

Ted Ryce: Yeah. And I’ve followed you for a while and I know you—at least on Twitter, you put out you share a lot of studies, talking about ancestral lifestyles, and what our ancestors may have been doing and how it’s different from what we do now. But in your book, you give some more recent examples, and the gold standard of this whole, or at least for me, when I started learning about this whole idea of like, oh, people used to do things way different before in these indigenous cultures.

And now we do things, just, we’re incredibly different from—we live our lives in a very different way. And that was Weston Price’s, Nutrition and Physical Degeneration. And you have shared some other information in your book, The Hungry Brain, looking at the Yanomami Indians, looking at someone from New Guinea. Can you talk a little bit about those comparisons that you make between those more traditional cultures and what happened when they adopted a more modernized lifestyle?

Stephan Guyenet: Yeah, absolutely. So there’s kind of an overarching principle here that I like to emphasize, because I think it’s really kind of a good way of organizing your thinking on this.

Ted Ryce: Sure.

Stephan Guyenet: That is that traditional cultures are limited in technology and they’re limited in affluence. And so they’re limited in their ability to satisfy their own innate food and lifestyle preferences. Whereas today, we have a lot more technology, we have a lot more affluence. And basically, we can cater to our hardwired preferences for food and for lifestyle and for sedentary behavior, to an extent that we’ve never been able to do before in history.

And so when you look at these hunter gatherer cultures, I mean, eating too much over long periods of time is really not a concern that they have, the concern that they have is eating enough. And this is true in any non-industrial culture, almost any non-industrial culture you look at. And it’s not that they’re necessarily on the brink of starvation, most of them are not on the brink of starvation.

But that doesn’t mean that calories aren’t important, because calories are very important for both immunity and reproduction. And I’m talking about not just enough calories to keep your metabolic functions happening, but I’m talking about enough calories to ramp things up and expend more calories than you would typically expend, so to have some reserve capacity.

So the immune system is a huge energy hog. And if you look at what kills people in the “wild” really traditionally living societies, infection is one of the probably the number one cause of death. So if your immune systems not quite functioning, as well as it could be, you will die of some kind of infection, and especially as children, because that’s even more of a problem for children, as their immune systems develop, if they don’t have enough energy, they’re going to succumb...

You see this still in lower income communities in Africa and other parts of the world, if you don’t get enough calories, you’re going to get some kind of diarrheal disease or something like that, and you’re going to have a high risk of dying. And furthermore, we know that having kids requires a lot of calories, right? I mean, as a woman, particularly, you have to make a baby, you have to make breast milk. And as a man too, in most cultures, the man is partially responsible for providing calories to his family.

So you have to have that capacity to bring in enough calories to do all those energy-intensive things. And if you don’t, then you’re going to pass along fewer of your genes and natural selection is going to select against you. So that’s kind of the basic principle for thinking about why our brains are so focused on energy.

For literally millions of years, energy was one of the primary determinants of the natural selection process that gave rise to what our brains are today. And so you have these cultures, these hunter-gatherer cultures that, I mean, really, the way that their brains work is perfect for their environment, like the Hadza. But it’s the same in any hunter-gatherer culture, but I’m   use the Hadza as an example, they’re a hunter-gatherer culture in Africa.

And they’re one of the very few, maybe the only true hunter-gatherers left on this planet. And what they do is they’re hunting and gathering strategy is focused on getting the highest possible calorie return rate. So calories gained minus calories expended, when you model their behaviour, that’s the primary determinant of what resources they’re going to go after.

And so they’re going to go after the things that deliver the most calories like…  honey is a big one, tubers are not super calorie dense, but they’re really easy to get. And when they have a windfall of calories, so if they kill a big animal, especially if it’s fatty, or they get a bunch of honey, they exhibit extraordinarily gluttonous eating behavior.

I mean, they will eat pounds and pounds of meat at a setting. They will literally drink a pint or up to a quart of honey at a sitting just like it’s a glass of milk, just drink it. They’ll eat huge amounts of nuts, huge amounts of fruit. When it’s easy to get, when it’s readily available, they will just absolutely gorge. That’s how the human brain is designed. It’s designed to be opportunistic.

When you have a resource that’s easily accessible and highly beneficial, you take advantage of it to the maximum extent possible. It’s like finding a $5 bill on the sidewalk, of course, you’re going to bend down and pick it up, it’s really easy for you to do. That’s kind of how the human brain is set up.

And the problem now is that we have those exact same impulses, those impulses are hardwired, those aren’t things that we mull over in our rational brain. Those are impulses that are hardwired in the non-conscious brain and that we perceive as motivations when we feel those motivations. But again, we’re not generating those motivations, we’re not controlling those motivations, although we can choose to act on them or not.

Ted Ryce: I’d love to interject there for a second, Stephan. So many people think that if they’re overweight or obese, that there’s something really wrong with them, like they’re a failure, they’re loser, they have no willpower, when in actuality, or at least in the majority of cases, I guess you’d agree that it’s just people aren’t aware of what’s driving their behavior.

They’re not aware of a word that you used earlier, and you use in your book, “the food environment,” and how we’re just our brains are kind of working against us. And you mentioned a term in your book, something that I think I first heard from, I can’t remember the guy’s name, but he was a big fan of barefoot running.

But it’s an evolutionary mismatch, a mismatch between how our genes are wired, and the functionality of the physiology after you know, the gene sort of develop, the brain and all the hormones and all those other things and then the environment.

And you’ve done a great job of telling us how the US used to be different, telling us how hunter-gatherer societies are very different and how that they exhibit the same types of behaviors you see in like your industrialized societies, where they gorge on things. 

Can we dive into some of the brain parts without going too deep into maybe the neurophysiology and the neuroanatomy? Can you tell us what’s at work with our brain or hormones and those non-conscious influences that are driving our behavior many times without us even recognizing it?

Stephan Guyenet: Yeah, absolutely. So first, I just want to address the thing that you brought up initially, and that is, you know, people feeling guilty or responsible for being overweight and obese. It’s my belief that is actually normal to be overweight or obese in the context of our current society. I mean, we’re surrounded by so many influences that are pushing us in that direction. It’s really not that surprising; it doesn’t seem like any particular failure to be gaining weight in this scenario.

And secondly, differences in body weight between individuals in our current environment are primarily attributable to genetics. So differences in body mass index, about 70 to 80% of that, in the context of the modern United States is attributable to genetic differences. So I mean, yeah, so basically, how you chose your parents is the number one of whether you’re fat or lean.

I want to clarify real quick that, that doesn’t mean that environment doesn’t matter. It really does matter, and people with the same genes, there’s a lot of nuance around what that finding actually means. But without getting into the details, just to give you the bullet point, environment can still have a very, very profound impact on body fatness, even if you’re a person who is genetically susceptible to obesity. But if you just kind of go with the flow, and do what everybody else does, genetics are going to be the main thing that determines whether you’re fat or lean in a particular environment.

Ted Ryce: So, 70% of us if we’re already kind of predisposed to becoming overweight or obese. And if we just go with the flow, we’re going to become that way, almost definitely.

Stephan Guyenet: Sort of. Just to clarify a little bit, what it means is that so if you look in a population of people, you’re going to find people of all different weights, and that’s the so called variability in weight. And 70% of that variability is explained by genes. So it’s not exactly the same as saying 70% of us are genetically susceptible.

So genetics affect body weight in all of us, and we’re all on a spectrum. But 70% of those differences are explained by genetics, 30% are explained by differences in your environment, like what kind of neighborhood you live in, what grocery stores near you, what shows you watch on TV, stuff like that. But I mean, I think most of the people who are obese or overweight or probably they’re mostly because of genetics, most of the people who are lean or probably they’re mostly because of genetics, too.

Ted Ryce: I’m just thinking of all the fat shaming people out there and, you know, it’s just kind of painting a different picture listening to you of what’s really going on. Please continue.

Stephan Guyenet: Yeah, I totally agree it. I honestly think that a lot of lean people really enjoy being kind of self-righteous about their own behavior and pointing out the behavior of people who are overweight or obese. And I think that they like to assign virtue to themselves. They like to believe that their leanness is the result of good decisions that they made rationally, unconsciously.

 And I think the genetic evidence really argues against that, that most of the reason they’re lean, honestly, is that it was handed to them genetically. Again, that doesn’t apply to everybody, there definitely are people who are diet or exercise nuts that maybe would have been overweight or obese otherwise, and they aren’t because they have healthy lifestyles, and  that is something that happens, and is real.

But I think most people, they’re just kind of lean, because that’s how their bodies are set up, but they like to believe that it’s due to rational decision so that they can assign some virtue to themselves and some lack of virtue to other people just as a way to kind of feel superior.

So anyway, that was responding to the first part of your question, but I’m trying to remember what...

Ted Ryce: The brain physiology. Sorry, Stephan, I do like these three part questions. I know everybody’s like, “Ah! like, eight questions in there, Ted.” So yeah, the second part was on brain physiology. And what’s going on at work with our brain, the hormones with what’s leading to these non-conscious impulses that so many of us are just not aware of?

Stephan Guyenet: Yeah, so I think there are probably a number of different brain functions that are contributing. And I focus on a few of the ones that I think are most influential in my book. And I want to emphasize that this is not just some nebulous concept, we really know quite a bit about what the specific brain regions and specific brain processes are that are contributing to our excess eating behavior, and excess body fatness.

So I’ll just mention a couple that I’ve looked into in some depth as a way to kind of illustrate these principles. So, one of them is something that is referred to as the energy homeostasis system. And this is a system in the brain, a part of the brain called the hypothalamus, which is on the kind of bottom center of your brain, really small brain region, very, very ancient. And this part of your brain specifically regulates, among other things, the amount of body fat that you have on your body.

And so it kind of works like a thermostat. So your thermostat, you set it to a specific temperature, let’s say you have it set to 68 degrees, if the temperature starts to fall, there’s a thermometer in there that measures that drop in temperature, and then it sends a feedback signal for your heat to kick on to bring the temperature back up. So if it goes down to 66, it detects that and brings it back up to 68.

So that’s kind of how the hypothalamus works, it measures the amount of body fat that you carry, via a hormone called leptin, which is secreted by your fat tissue in proportion to its size. So it gets in your circulation, it goes to the brain, your brain says, aha, you have however much body fat on your body. The key thing is your brain really is looking for a certain level there. Your brain is accustomed to a certain level, and that’s the level it wants you to have.

And typically, that’s the level that you’re currently at, unless you’ve specifically been trying to lose weight lately. And then what happens is if that signal goes down, and the way that signal goes down, if you are losing body fat, and/or if you’re eating fewer calories, that signal goes down, and your brain says, “Hold on, wait a minute, we’re losing fat here, and I really don’t like this.”

And so it initiates a suite of responses through its connections with many other parts of the brain that’s designed to oppose that fat loss and get you to bring the fat back. And so it does, it increases your hunger levels. It means that you have to eat more at a meal to feel full. It means that you pay more attention to food, your attention processes are altered. It means that you have more cravings, especially for calorie-dense foods that would really bring that fat back quickly.

It means that in many people, they become less motivated to do physical activity, it shuts down your metabolic rate. If you lose sufficient weight, it’s it starts to disproportionately lower your metabolic rate, so you’re burning fewer calories. And you may also feel cold and sluggish as a result of all those things happening. So it basically does everything it can to bring the fat back, and it’s very persuasive.

And the evidence for that is not hard to come by; almost any weight loss approach will cause people to lose weight, it doesn’t matter if it’s low carb, low fat, Paleo, whatever it is, will cause people to lose some amount of weight. But if you follow them long term, what you see is that people have a very hard time maintaining that they tend to go back up to their previous weight, or at least close to it over a period of years.

And we know that a lot of that has to do with this system that does not want you to lose weight. It’s literally a starvation response. That’s exactly what it is. You see the exact same thing in people who are starving. And you see the same thing in people who are born without the leptin hormone. Because that hormone, when there’s none of it, your brain’s like, “Holy crap, we are just about to die of starvation.” And these kids are just insatiable, they want to eat everything, so it’s really…

Ted Ryce: Yeah, let me interject for a second because I feel like there are people listening right now who know that situation very intimately. And for anyone who’s listening. And if you’ve been on a weight loss journey, and you’re like, “Oh, I start to cut back my calories, I started losing the weight, I was so happy. But then somehow, I was less likely to follow through with my workouts, more likely to give into my cravings, because we only have so much willpower in our stressed out crazy modern lives. “

And if you notice that you keep coming back and going on what’s called the yo-yo diet phenomenon, then this is what’s at work, and I want you to pay attention to it. And, Stephan, this is one other way why tell people don’t try for dramatic change so quick, don’t try to lose a lot of weight, because this is what you’re fighting. And I’d love to hear your thoughts on that. Is it better to approach weight loss/fat loss from a more gradual perspective, so that we don’t have this over exaggerated starvation response?

Stephan Guyenet: So I’m going to answer your question, but I want to take a step back for just a second and add one little additional piece of information. And that’s that—so your brain regulates body fatness around this kind of comfort point, this level that it expects, this level of leptin that it expects, but that level goes up in some people.

And so people who are overweight or obese, they’re defending their weight around a higher setpoint so it as if the thermostat has been turned up. That system still works perfectly well, it defends their body fat level against weight loss, but it’s set to a higher level.

Ted Ryce: That’s the genetics you were talking about, the 70% genetics, or…?

Stephan Guyenet: Let me put it this way; that process is influenced by genetics, but it’s not determined by genetics. And so I think it’s the same situation where both genetics and lifestyle can impact that. But we don’t have a full understanding of how that works. That’s what my research was on.

Ted Ryce: We were talking about brain physiology hormones, you talked about what you call the fat thermostat and the hypothalamus, how we all have a setpoint, how it up or down regulates our different influences to bring back the body fat when we’re trying to get rid of it. And you said there are some other important mechanisms as well.

Stephan Guyenet: Yeah. And then, sorry, there was a question that you asked, the last question you asked me was something else and I can’t remember what it was. I was about to answer it.

Ted Ryce: Yeah, whether people should try to lose fat gradually...

Stephan Guyenet: Oh, yeah.

Ted Ryce: …Versus very quickly, to not exaggerate that starvation response? Is that a real thing? Or what are your thoughts and what does the research show?

Stephan Guyenet: It’s intuitively appealing, the idea that we should do it gradually feels less risky, it feels more sensible. But actually, what the evidence shows is that rapid, extreme change is more effective.

Ted Ryce: Interesting.

Stephan Guyenet: Yeah, it’s pretty consistent. When you put people on a very low calorie diet for a limited period of time—there are, I think, multiple reasons for this that I’ll get into in a moment—you tend to see greater final weight loss and you tend to see better weight loss maintenance.

So I think there are a couple of reasons for this, and one of them is that, yes, you do see a larger activation of the starvation response. But if you lose 50 pounds quickly versus gradually, you’re going to have about the same level of starvation response once you get to that 50 pounds loss.

So the question is, what’s the likelihood that you’re going to be able to maintain this intervention for the amount of time that it takes for you to get there. And that’s where fast weight loss really has an advantage, because it may be an extreme intervention, but it takes a lot less time to get there.

And people can be motivated for a period of weeks, maybe a period of months, they can be really motivated to achieve a goal. But eventually, you’re going to get worn down, when you’re fighting your non-conscious brain all the time, every day, you’re going to get worn down.

And I think that’s one of the big problems with slow approaches, is it gives you lots of time to get worn down, before you achieve your goal. So the other thing is that there is an emerging literature. And this is not something that I’m necessarily ready to hang my hat on quite yet.

But it’s an interesting idea that I’ve been tossing around in my head that’s consistent with some research, is that when you kind of shock your body with a period of kind of extreme negative energy balance, that means a lot more calories leaving the body than are coming in, you kind of start to reset some things in the body in a way that you might not with the less extreme protocol.

So you see, for example, just to give you one example, there are a couple of studies now showing that if you put people with diabetes, I’m talking about Type II Diabetes, and not necessarily people who have been diabetic for a long time. But if you put them on a very strict, very low calorie diet for just a few weeks, I think maybe eight weeks, you can literally reverse their diabetes. I’m talking about reverse, not just improve; you can reverse diabetes in the majority of people in that situation.

If you look at what that’s correlated, you can see that excess fat is going away in the pancreas, which is the organ that secretes insulin, you’re seeing some pretty profound metabolic changes. That doesn’t necessarily mean it’s a permanent cure. I’m sure those people could redevelop it eventually. But you’re kind of giving yourself this really powerful shock that I think starts to reset some of those deeply ingrained, metabolic issues that that people have developed.

And I wonder, and again, I don’t have direct evidence for this, but I wonder whether the very, very low calorie diets might reset some things in the brain as well. And I’m not talking about complete reset, talking about a partial reset, because that would explain why people tend to be able to maintain their loss better after those types of interventions.

And there is limited evidence on this. So I published a paper, it was in mice, but I published a paper a few years ago showing that if you take mice that have been obese for quite a long time, from a fattening diet, and you put them back on a very, very strict healthy diet.

I’m not talking about a calorie restricted diet, no deliberate calorie restriction involved, I’m just talking about putting them on a very healthy unrefined, lower calorie density diet, you see that they essentially almost complete reversal of all the problems, they lose a lot of their excess body fat, most of it. All the changes in the brain that we’re measuring in the hypothalamus that we find correlate with this damage that causes you to maintain a higher level of body fatness, mostly resolves.

So you really, at least in mice, again, I’m not claiming at the same thing was happening to people, but there’s at least some suggestive evidence somewhere that this is possible, this is something that could happen. And that’s something that I would invoke as a possible explanation for some of the evidence that we see in humans.

Ted Ryce: Well, you’re being the excellent scientist that you are, and you’re not making outlandish claims like so much of the health and fitness industry. And thank you for teaching me something because that’s why I have experts like you on because I don’t know everything or else I’ll just do all these shows by myself. So it’s a real privilege and honor to have you on here to help clear up some of the misconceptions that people listening have, as well as myself.

So it’s a faster, more aggressive approach, if you’re looking to lose fat can reverse Type II Diabetes. And when you say a hypo-caloric or calorie-restricted diet for eight weeks, how restricted are we talking about? Is there a number that someone right now listening could implement and shoot for? Or does it matter? Can you give us more details on maybe how someone could follow that?

Stephan Guyenet: I’m not 100% sure that these numbers are right. This is just what I remember off the top of my head about the study. But what I recall is it was something in the range of 500 calories a day for eight weeks.

Ted Ryce: Whoa.

Stephan Guyenet: Yeah, it’s very, very low. These people… Yeah. Like I said, it’s an extreme intervention. And these people were overweight and obese, so it’s not like... you know, you might want to consider other options if you don’t have much excess body fat to lose, but...

Ted Ryce: Right, this is not for the people who are like, “Oh, well, just this three pounds that I need to lose around my midsection.”

Stephan Guyenet: Right. And again, I’m not sure about the details of this particular study. But typically what they do for things like this is they give people a nutritionally complete food supplement. So something like a shake or bars or things like that, that have all the protein and essential vitamins and minerals that you need, so that your body is not breaking down, it’s not breaking itself down.

Really all it’s doing is experiencing an energy deficit and drawing on your fat reserves. So it’s just a way of kind of covering your nutritional bases, but not covering your energy requirements. That’s the concept behind it.

Ted Ryce: This is not something that anybody would want to follow unless they did that, is what you’re saying, unless they got the supplement that the people in the study were taking?

Stephan Guyenet: I think you could design it on your own, you could probably do it using whole foods, but you’d have to be pretty thoughtful about it, you’d have to really think pretty hard and know what you’re doing, I think. Not to say that it’s impossible at all. And you know, we’re talking about eight weeks, it’s not like you’re going to die of vitamin A deficiency over a period of eight weeks, or get scurvy or anything like that.

It’s an extreme intervention. And so people want to be pretty conservative about it. And typically, these things are done under doctor’s supervision. And I think that’s what’s recommended, that it be done under doctor’s supervision. And I can’t say, you know, I’m not going to say whether or not I agree that that’s necessary, but I will say that it’s possible to do without doctor’s supervision.

And the other thing that can be really helpful about using pre-prepared weight loss foods like these high protein shakes and things is that it sets very, very clear limits on your food intake. So, it’s been shown that if somebody else is making all the decisions for you about how much food you’re eating, such as, the rule is only eat this food that we deliver to your door, it’s a lot easier to lose weight, because you’re not having to make all these decisions in your kitchen about what you’re going to eat and what ingredients you’re going to use and measuring this and that.

Your only decision is to eat the food that you’re provided and stop when it’s over. So it really simplifies things and increases adherence. And also the high protein nature of those shakes and bars and things, typically, they’re very high in protein. And that high protein, lower fat and carbohydrate tends to suppress appetite. And so people actually typically report that after an adjustment period of a few days, they don’t even really feel that hungry, they feel good. They have high energy and stuff.

And I’m not saying that would have, obviously, you can’t stay on that forever, but in over a period of weeks, I think that that is something that people experience and report. It’s an effective approach, according to the evidence that we currently have.

Ted Ryce: Very interesting, even though yo-yo dieting is something that happens, but maybe with the 1200 or 1500 calorie per day diets, but you’re saying this very low calorie, 500 per day with these high protein balanced out shakes or bars can be super effective, and can possibly reset some things in your brain so you don’t have that exaggerated starvation response that drives you to sit on your butt or seek out some highly caloric foods like cookies and muffins and whatnot. Stephan, we’re coming up on our time, or do you have a little bit more time for a few more questions?

Stephan Guyenet: Yeah, absolutely. And let me just clarify a couple things here. One is I don’t want to give people the wrong impression that this is like a cure or something. See, the typical response is there will still be some rebound weight gain after that loss, even with these approaches I’m talking about, so I don’t want to give people the impression that this eliminates weight regain or that this is like some silver bullet, it’s not. But it does appear to be more effective than typical approaches.

Ted Ryce: Duly noted. So in your book, you have a part that has some practical steps and that’s what I’d like to focus on now. You have “Six Steps for a Slimming Lifestyle.” And we’ve already talked about this hypo-caloric diet and how that could be something that really helps people. Can you talk about some of the steps that you mentioned, perhaps the ones that you think are misunderstood or underappreciated?

Stephan Guyenet: Yeah, sure. So I think that most people are not necessarily going to want to do that approach that I just outlined to you, with the very low calorie diet, most people aren’t going to want that.

Ted Ryce: Oh, it sounds terrible, I’m not all the way, but I was terrible,

Stephan Guyenet: I would do it if I had Type II Diabetes, I’ll tell you that right now. I can’t recommend that for liability reasons, but if I had Type II Diabetes, I would do that. That would be like the first thing I would do.

Ted Ryce: Wow!

Stephan Guyenet: But anyway, putting that aside, I don’t think that’s necessarily what most people need or want. And frankly, by far, the best strategy is prevention, you’re going to get way more return on your effort and way more efficacy, if you prevent fat gain, rather than trying to reverse it once it’s already established.

And that’s for the reasons we were talking about; the brain kind of locks that in. Once it’s up there and once you’re comfortable at that way, your brain doesn’t want to lose it, and it matches your appetite and energy expenditure accordingly to maintain that higher level. So the best thing you can do is just prevent that from happening.

And before getting into the six steps that I outlined, I want to kind of throw something out there just kind of like a little fact that I think is really helpful. And that is that most weight gain in the United States—and I think this is true, probably globally, but certainly in affluent countries—is associated with the six week holiday period. And we are in that right now.

This is the period of the year where people gain more weight than any other time of year. And most of that weight, they don’t lose after the holidays, so it ratchets up their weight. Every year when we go through this six week period, it ratchets up their weightand they tend to hang on to that only to build on it the next year.

Ted Ryce: This all like modern society, like UK, Australia, places in Europe?

Stephan Guyenet: So I don’t have specific data on anywhere besides the United States, Germany and Japan, but I can tell you that it happens in the US, Germany and Japan. And I think it’s likely to be just kind of a general principle. So yeah, the point I’m trying to make here is that the six week holiday period represents 12% of the year. So that is a window of time where we can get a lot more return on our effort than during the rest of the year.

So if we’re really focused on preventing holiday weight gain, we can prevent most of our annual weight gain by a relatively small amount of effort relative to what we would be doing if we were vigilant all year. So that’s just kind of a little fact I want to put in people’s heads to keep in mind.

So I think one of the steps that’s most important and not necessarily appreciated in proportion to its importance is the food environment, controlling your food environment. So your food environment is simply the foods and the food cues that surround you each day. So that’s mostly at home, mostly at work, but also on your way to work: billboards, driving by fast food, restaurants, seeing logos, advertisements, that sort of thing.

And we know that the human brain is very reactive to the cues that surround it. And this is true of any animal, and it’s true of humans as well. We react in proportion to the things that are around us. So if I put a plate of doughnuts right in front of you right under your nose, you’re more likely to eat it than if I put it two feet away, you’re more likely to eat it than if I put it five feet away, you’re less likely to eat it if it’s two feet away, even less likely, if it’s five feet away.

And we’re talking about trivial differences, right? This is trivial. These experiments have been done. I’m not just pulling this out of thin air. And then if I were to put it somewhere where you can’t see it like in a drawer, you would eat even less. If it was a drawer that you had to get up and walk across the room to get to, you would eat even less.

And we’re talking about big differences in intake from these absolutely trivial effort barriers and visual barriers, so you’re not getting the cue, and you’re having to expend a little bit of effort that can have a huge difference. And these are just little illustrations of the power of the food environment. So what you really want to end up with, overarching principle, you want to end up with a food environment that makes good choices easy, and bad choices, inconvenient, or difficult.

And so at home, you don’t want to have any tempting calorie-dense foods within sight, you don’t want to have them easy to grab. And then all the things that are in your home, you want to be things that you feel like are supporting your health and nutrition goals. And things like raw fruit, things like nuts in shells, where you have to expend a little bit of effort, like I have a big bag of peanuts that are in shells, and they’re unsalted, so they’re not super tempting to begin with.

If I’m genuinely hungry, I will go and I will shell peanuts, and I’ll eat them and maybe I’ll have an apple. But if I’m not genuinely hungry, I’m not really going to open the bag and start shelling peanuts. It’s just a little bit too much work and it’s not enough of a reward, you know?

Ted Ryce: Yes.

Stephan Guyenet: So that’s just an example. That’s the food environment, I think that’s very, very important. Another thing that I think is underappreciated is food reward, and that’s the motivational value and pleasure value of food. So different foods motivate us to different degrees. Most people aren’t as excited about celery sticks and brussel sprouts, as they are about ice cream and cookies, and pizza, and whatever, just on a very visceral craving, motivation level.

And I’m no saint, I’m not immune to these things, I have a hard time resisting pizza, I have a hard time resisting cookies, or whatever, when they’re in front of me, and that’s those impulses that are in my brain. I would turn it off if I could, but I can’t. And so I try not to put myself in those situations, and I try to watch the reward value of my food. So the more tempting and pleasurable that food is, the more of it that I’m going to eat, the more of it that people tend to eat.

And it’s more than just passive over eating; there are actually connections in the brain, between those pleasure and motivation centers and the parts that regulate your appetite and your body fatness. And when you start eating foods that your brain perceives as highly valuable, so those are those foods that you’re intrinsically motivated for and intrinsically get a lot of pleasure out of, it starts to shut down your fullness mechanisms, and it starts to allow—basically facilitate the consumption of larger amounts of those foods that your brain instinctively views as really valuable to your body.

Ted Ryce: So that hunter-gatherer drinking that pint honey all over again, right?

Stephan Guyenet: Exactly. I mean, from a hunter-gatherer perspective, pizza would be an amazing score. I mean, that pizza would probably literally, at least in some ways, literally be good for them, because that’s delivering them the calories that they need to fight off infections and have babies and trek around six miles a day around their environment and climb trees and lift rocks. And so the brain is hardwired for those things.

And it will sweep away barriers to the consumption of those items, such as the inconvenient fact of feeling full. But at the same time you have to enjoy your food to some extent, or else it’s not sustainable. So I don’t think the answer is to eat hyper bland foods, even though that does help with weight control and appetite control, I don’t think it’s especially sustainable. And so you have to find a balance.

And for me, what that balance is, is I try to eat foods that are satisfying, I try to eat foods that are made with quality ingredients, but not eat foods that are so, so delicious and so crave-worthy that I tend to lose my normal control over eating them, you know, and so it’s there’s definitely a gray area, but I think people intuitively understand this principle. And I think that it’s an important one to apply to your diet for weight control. Those are two out of the six guidelines.

Ted Ryce: Yeah, fantastic stuff and I think we’re moving in this direction with health and fitness information specifically with nutrition, that it really is all about the food rewards, the food environment, how our brains are causing us to do things that sabotage our efforts to maintain a good level of body fatness of health.

And it’s just a pleasure and an honor to have you on, like I said before, because you’re one of the people out there who are putting out this information that—I mean, this is this so invaluable. It’s so important. And it answers the questions and fills in the blanks that so many people have as to why they can’t get the results.

And there are so many people who are exploiting that in selling them things that aren’t backed by science that, you know, maybe sometimes they work or maybe not, but you’re putting something out there, that’s helping people start to empower themselves. So thank you so much for coming on the show today, for talking to us about your book, The Hungry Brain: Outsmarting the Instincts That Make Us Overeat.

And if you’re listening right now, you just had an amazing education about the cutting-edge science of what these guys know, what guys like Stephan know about what’s really going on, why we’re overweight, why we’re unable to control ourselves, and I highly recommend his book. I’ve just started it; it’s amazing.

And Stephan, where would you like people to go? We’ll put up the link to your book in the show notes, of course, but is there anywhere where you’d like people to go to learn more about you and to purchase your book?

Stephan Guyenet: Yeah, sure. So my blog is wholehealthsource.org. And I’m going to be migrating it soon, but that URL will continue to work. And my book is available in a number of places. 

Ted Ryce: Excellent, so fantastic. And again, if you’re listening, and you’ve been struggling with your weight, struggling with getting results, and you’re exercising, and you’re doing your best to watch what you eat, go on over, pick up this book, so you can see you’ll be ahead of, I want to say, Stephan, 95%, at least of the health and fitness professionals out there.

I mean, I even learned a bunch of new things. But one thing in particular, you said that a more drastic approach happening at the beginning, it can lead to more long term success. So just imagine what you’ll learn when you read this book, so fantastic. Stephan, was there anything that I didn’t ask you or we didn’t talk about that you think people listening need to know?

Stephan Guyenet: I mean, there’s a lot of other things I could get into that are in my book, but I think we covered a good amount of material for one day.

Ted Ryce: I hope you had a good time. We’ll have to get you back on for round two. You’re just someone who I really feel like people need to know more about what you’re researching, so it can benefit them.

Stephan Guyenet: Thank you. It was my pleasure.

Ted Ryce: Welcome to the Ted’s Takeaways segment from the interview. This is where I’m going to discuss some of the biggest takeaways from the episode. In case it was a bit high level, perhaps it was a bit sciency, perhaps it was a bit like drinking from a firehose, I’m going to distill some lessons down for you and keep them short, keep them simple.

And the first lesson is that there is nothing wrong with you. You are completely normal. You are wired to eat, you have a hungry brain, and it’s getting you to make all sorts of unconscious decisions about your choices with food. That said, it’s our responsibility to start to manage those choices. And what did Dr. Stephan Guyenet talk about? He talked about food environment.

And I want to refer you also to Dr. Brian Wansink episode as well, because if you haven’t listened to that one, Dr. Brian Wansink talks a lot about how to structure your food environment. And Dr. Stephan Guyenet is talking about why it’s so important because of our wiring. So make sure you listen to both episodes.

Make sure you put into practice some of the tips to manage your food environment, like storing those pretzels, cookies, ice cream, whatever, as far away from you as possible. And as far away doesn’t mean in your cupboard or in your pantry, it means really get a freezer and put it in the laundry room. Store your pretzels in the laundry room, store all that junk in the laundry room. Make it harder for you to go and get it, because if it’s out there on your counter, you’re going to be more likely to eat it.

And of course, you can just not even buy those things to begin with. That’s what I do. That’s what I practice, because otherwise I’d be a really overweight guy. That’s the truth. I have pretty strong cravings. I love ice cream. I love junk food, I just happen to manage my food environment better than other people who have the same tendencies as me. But don’t employ those tactics. So, manage your food environment.

And again, there’s nothing really wrong with you, you’re completely normal. If you eat too much, if you’re driven to eat, if you emotionally eat, that’s all normal. However, it is still your responsibility to deal with it. 

So the second thing is make sleep a priority. When we’re sleep deprived, we know that it’s well documented that our satiety hormone, leptin, goes down, our hunger hormone, ghrelin, goes up, and you’re more likely to reach for food.

And what do you go for? You say, “Hmm, I sure could use a kale shake or superfood salad.” Of course not, you reach for the chips, the Ramen, the pasta, the cookies, the chips, the ice cream, I think I said chips twice. Maybe that’s a shout out to Martina if she’s listening, because that’s her favourite—that’s one of our coaching member’s favorite foods. For me, it’s ice cream.

So, make sure that you get adequate quality and quantity of sleep, because if you’re having trouble managing your cravings, it means that your brain is missing something. And if that something is sleep, then that can be fixed by listening to one of the many episodes on sleep, just go to legendarylifepodcast.com, type “sleep” into the search bar, there’ll be a ton of things that come up.

And the third thing that I want to mention is manage your stress. In fact, I’ll do one more but manage your stress. Because not only does sleep tend to cause us to eat in ways that make us rounder around the midsection or wherever you have your trouble spot, right? For me, it’s around my abdominals and back. Also, stress makes us do that, right?

Food reward, you’re stressed out, you had a tough day, you’re like, “You know what, I’m just   eat until I feel better.” And how do I know this? Because I do it too. We all do it. And when I’m managing my stress, when I’m doing things to make myself feel good, like exercise, like eating healthy food, because I feel good after drinking a vegetable juice or eating a nutrient dense salad, I am less likely to go off track if I can maintain those things.

But if I’m stressed, if I’m unhappy, those are the things that drive me to reach for things that I shouldn’t or go eat more than I should or whatever it is, even if it’s good food, if you overeat, it’s still going to be a problem. So make sure you manage your stress. And how do you manage your stress, you can type in stress at Legendary Life podcast in the search bar.

A bunch of things will come up; everything from things that you can do right away like meditation. A quick one would be download the Headspace app and give it a try, a 10 minute meditation, you won’t believe how powerful meditation is for reining in that terrible wired, but tired feeling that you have if you’re under quite a bit of stress, to going on vacation, which is definitely a bit more involved, logistically and financially, but super effective. So make sure you do that.

And the last thing I want to talk about is you’ve got to move your body. It drives me crazy with dieters, they’re like, “Oh, I’m on a diet, but I lost weight, but I don’t look the way I want.” It’s like of course you don’t, where’s your muscle? You may even have lost muscle. Some of that weight you are so happy about losing might have been muscle mass, which is not doing you any favors, having less muscle on your body. So you need to move your body.

So that’s what I’m going to leave you with. Make sure you start to put this into action. It’s not about the information, we have enough of it. I want to know what you’re doing. So keep that in mind, implement some of this, and I’d love to hear if you were able to manage your food environment or if this got you to think about things better. Give me an email, shout out on Twitter or Facebook, and let me know. 

That's all I’ve got. Hope you enjoyed this interview. And on Friday there will be a new Real Talk episode, and this time we are going to talk about the secret behind finding balance between your work life, your social life and your health.  

It’s so important to find balance in our life, and unfortunately many of us struggle with this. So, if you want to learn how you can achieve this balance in order to live a better life, tune in for Friday’s episode! Talk to you then!