January 13, 2018
[05:44] About Stephan Guyenet
[07:45] Why What Stephan Presents in his Book is Absent From All Popular Theories of Obesity
[12:10] The Story of the Fattest Man on the Island
[18:50] How Chocolate Serves as a Prime Example of Reinforcing Properties that Characterize Modern Food Addictions
[23:15] Why Kids like Ice Cream and not Brussels Sprouts
[29:00] How You Can Beat the Buffet effect
[36:05] The Three Things All Non-Industrial Diets have in Common
[49:05] Why our Hunter-Gatherer Neighbors can be Gluttonous and Yet Not Obese
[57:00] A Simple mechanism you can Use to Fight your Natural, Ancestral Tendency to Overeat
[1:04:69] The Lesioned Rats and What This Satiety Center and the Satiety Factor Is
[1:15:10] Why the people from the Biggest Loser gain so much weight back after the competition
[1:25:23] What Exactly is Going on in Terms of Cortisol and Excess Calorie Intake?
[1:24:45] A Cortisol-like Drug That Causes Intense, Unconstrained Eating
[1:31:42] End of Podcast
Ben: Yo, yo, yo. Stephan, my guest on today’s podcast, has a very interesting last name. Some people think its “Guwayanet”, some “Giyonee”, some “Guwayanay”. Either way, I don’t care coz he’s a smart cookie; he’s got super-duper high smarts in the smarts category specifically when it comes to nutrition. And he has one of the best books I think I read in 2017 on nutrition specifically; it’s called “The Hungry Brain”. It’s basically about hunger and overeating, but it’s not insulting your intelligence by telling you about how if you sleep, you’re more likely to grab a Snickers bar. I mean if you don’t sleep, you’re more likely to get a Snickers bar, no. Instead he delves deep into things like mice and rodent research and, dude, you gotta read the book; you gotta listen to the interview and you gotta read the book. My apologies if he’s like super-duper-duper scientific. I’ll try and keep him reeled in during this episode, but either way, you need to own the book even if it takes you a year to read because it’s so scientific. Read it, why are you hungry and what to do about it.
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Hey, you might have heard that podcast on energy medicine and yoga and how it jives with Christianity that I recorded with a pastor from Moscow, Idaho named Toby Sumpter. Well Toby, like I mentioned on that show, has his own podcast along with a few other very cool folks. The hosts are pastors, deacons, film makers, and they do everything from interview pretty notable presidential candidates like Senator Ted Cruz and Dr. Ben Carson, they do book reviews, they make films, and their podcast is incredibly entertaining and educational… “edutational”? “Edutainment”? Educational and entertainment combined; you make up the words. Anyways, they mix together pretty taboo topics; it’s like this taboo formula of faith and culture and politics and they’re just like cool, good old middle America… I guess they’re not middle America, they’re Pacific Northwesters. But they’re good dudes living in a great community that I’m pretty plugged into and their podcast is actually quite entertaining and educational, not to kick those two words to death. Anyways though, check it out: CrossPolitics. Where do you listen in? Go to crosspolitic.com/episodes. Cross, you know like the cross, and politic; crosspolitic.com/episodes. Check it out, subscribe, give it a listen.
In this episode of the Ben Greenfield Fitness Show:
“We know that animals and humans that are obese, that have obesity, require a higher level of leptin to stop that starvation response. And so they literally have a higher set point, it’s like turning up the heat on your thermostat…” “It is true that a lot of our processed food comes from corn and soy beans and we eat a lot of processed food, but you find the same thing in non-industrial cultures where most of their calories are coming from just a few staple foods.”
Ben: Hey folks, it’s Ben Greenfield and I gotta tell you, most of us try to eat well, we try to avoid weight gain but a lot of times our actual behavior, our actual cravings don’t live up to those lofty intentions. And a neuroscience obesity researcher and today’s podcast guest Stephan Guyenet argues that we’re actually betrayed by our own brains, by our own ancestry that drives us to crave and to overeat food, and he just wrote this fantastic book called “THE HUNGRY BRAIN: Outsmarting the Instincts that Make Us Overeat”. Frankly it is, and maybe it’s just coz I’m a complete nerd, one of the best scientific treatises of why we eat the way that we do, why we get hungry, and why certain things really spark our appetites and why even when we’re following a diet we find ourselves digging for chocolate ice cream or Ben & Jerry’s Chunky Monkey at midnight. So we’re gonna delve into all that today, and it really is stuff that goes way above and beyond the current popular theories of obesity and appetite and overeating in this book. It really is pretty ground-breaking; I will take everything that Stephan and I talk about and put it over at bengreenfieldfitness.com/hungrybrain if you wanna check out his book or anything else that we discuss. Bengreenfieldfitness.com/hungrybrain, and by the way if you don’t know who Stephan is, he’s a smart cookie. He’s an obesity researcher, he’s a health writer, he has a PhD in Neurobiology at the University of Washington, he runs a blog called wholehealthsource.org and he lectures all over the friggin’ planet on things like obesity and metabolism and diet. So this dude knows his stuff. Stephan, welcome to the show, man.
Stephan: Thanks, good to be here, Ben.
Ben: Yeah, yeah. This book, when I sat down and read it, I had so many pages folded over. I wasn’t really quite sure where to start, but I guess the main thing for me is you launch into the book about why what you present in it is absent from popular theories of obesity. Meaning there’s all these theories out there about why people get obese but you say a lot of what you present in the book isn’t in those theories and I was wondering if you could kinda explain why that is, why you even had to write this book.
Stephan: Yeah, yeah, absolutely. I think that’s a good way to introduce this, and I wanna preface this by saying that I’m not saying these theories of obesity are necessarily wrong or are not useful, but I think they’re all missing something and I’ll explain what that is. So there’s the theory of “calories in, calories out” that basically your body fat is determined mostly by voluntary behaviors and willpower, you distract your calories and that’s gonna be your most effective way to manage your body composition. There’s the idea that carbohydrate is the primary determinant in body fatness by its impact on insulin. There’s the idea that physical activity is a major determinant, there’s emotional eating, there’s food addiction. These are all leading popular concepts of the causes of obesity and I think that a lot of them do actually have some value. But I think that if we really wanna understand why we overeat and why we carry excess fat and really wanna understand what ties all these things together, we have to look at the brain. Because the brain is the thing that determines all of our behavior, including our eating behavior as well as everything else. It determines our feelings such as our cravings, it determines our hunger level, and it determines a lot about our physiology that determines how our body uses the food that we eat.
Ben: Versus say like our pancreas or our insulin or the incretin hormones formed in our gut, et cetera, you’re saying it all starts in the brain?
Stephan: Yeah, and I’m not saying that there’s nothing outside of the brain that matters. What I’m saying is that the brain is kind of the central regulator of a lot of this physiology, and certainly it’s the only regulator of our behavior, or it’s the only thing that generates our behavior, I should say. And so I think that, and there are reasons why understanding the brain doesn’t really tend to enter in popular theories of obesity, it’s because the brain is complicated and because until recently, we didn’t really have enough information in the research world to come to useful conclusions about the role of the brain in a lot of this stuff. And so, it’s only recently with the real explosion of neuroscience research and techniques for doing that research more and more effectively; only in the last couple of decades really have we gained some really very profound insights into how the brain generates all these things that we care about related to food intake and body fatness. And I think that when we take that brain-centric perspective, I think that’s the most useful perspective because we’re really focusing on the thing that is actually central to all these things that we care about instead of kind of peripheral things that are output of the thing that we really care about.
Stephan: And so I think that there’s a lot of this information in the scientific community that I think is very, very profound and helps us understand at a very deep level what’s going on, but a lot of it hasn’t really trickled down into a general audience context because it’s complicated. And so my goal with the book was to take all this complicated stuff and kind of like streamline it and package it in a way that a sophisticated general audience can understand.
Ben: Yeah, and you talk about a lot of that research in the book from mice to rats and beyond. There’s some freakin’ fascinating stuff that I wanna get in to regarding this new research that you hinted at. But first, tell me about the story of the fattest man on the island and why include that in the book, coz I thought that was great.
Stephan: [laughs] Yeah, so one of the things that I’m really interested in is the question of what is biologically normal for humans, because we can look at statistics for the United States and we could say what’s statistically normal for the modern United States, but that doesn’t really tell us what’s biologically normal. That doesn’t really tell us how the human body evolved functions, so I think that’s a really important question to answer. And to answer that, you have to start looking at non-industrial cultures; you have to start looking at archaeology, hunter-gatherer, non-industrial agriculturalists and you have to see. What is their level of body fatness? What is their health? Are they getting diabetes? Are they getting cardiovascular disease and how are they living? What is their diet? What is their lifestyle and can we get any clues from that about the connection between diet and lifestyle and obesity and health outcomes? And so, to kinda start to get at some of these questions, I use a story that I think is a pretty striking illustration of this principle which is Staffan Lindeberg, his research in the early 1990s I believe. Staffan was a researcher at the University of Lund who was fascinated by evolutionary health.
Ben: The University of Lund? Where is that?
Ben: Okay, gotcha.
Stephan: Yeah, and he was fascinated by this idea of evolutionary health and he wanted to do research to see how much credibility this idea had. So he went to this very isolated island in the Pacific; it’s considered part of Melanesia and the island is called Kitava. And it’s one of the Trobriand Islands and people living there are scarcely touched by industrialization, at least they were at the time of the study. And they’re horticulturalists which means they grow primarily tubers and plantains and things like that, and they had a very simple starchy diet that was mostly starches that they cultivated plus coconut, fish, and some vegetables. And what he found was on that island, there was one person who really stuck out; there’s basically no obesity and there are almost no people who are even slightly overweight on the entire island. We’re talking about thousands of people; this is like totally unimaginable in any industrialized society, right?
Ben: Like that complete opposite of the cruise ship on the cartoon Wall-E.
Stephan: Oh yeah, that’s right. It didn’t look like people on a cruise ship, and you look at these people, they’re not starving. And in fact he talks about in his paper how they had excess food, like they would often discard food coz they had too much of it. And not to say that their food supply didn’t fluctuate but there was no recorded famine on island in recent history, and you look at these people and they’re lean, they’re well-muscled, they really don’t look like people who aren’t getting enough to eat. But yet there’s very little obesity except for this one guy that he found; this guy who, in my book, I call Utala. I’m just gonna read a little bit, I’m gonna this passage.
Stephan: As it turns out, Utala wasn’t living on Kitava at the time of Lindeberg’s study, he was only visiting. He had left the island 15 years earlier to become a businessman in Alotau, a small city on the eastern tip of Papua New Guinea. When Lindeberg examined him, Utala was nearly 50 lbs heavier than the average Kitavan man of his height and 12 lbs heavier than the next heaviest man. He was also extraordinary in another respect: he had the highest blood pressure of any Kitavan examined by Lindeberg. Living in a modern environment caused Utala to develop a modern body. So he was born on Kitava, he grew up in Kitava just like everybody else but then he went to Papua New Guinea and began living a more industrialized lifestyle as a businessman.
Stephan: And so he had the same genetics as everybody else, the same in utero, all the prenatal epigenetics, all the childhood nutrition was all the same but as an adult, he was exposed to this industrial diet and lifestyle, and it made him overweight. He was basically just under being obese on the body mass index scale; just below being obese. He had a lot of abdominal adipose, and so I think to me that’s a really striking example. And you see this all over the world. This is like an anecdote that illustrates my point kind of in a colorful way but you can look at data that are not anecdotes and it shows there same thing; that it’s not just genetics. When you take people who are living a traditional lifestyle and eating a traditional diet, and they shift on to an industrial diet and lifestyle that more closely resembles affluent countries like the modern United States, you see dramatic increases in body fatness as well as diabetes and coronary heart disease and other things that are associated with that.
Ben: Yeah, there’s actually a really good book about this that goes into all sorts of different populations from Hispanics to African-Americans, it’s called “The Jungle Effect” and it is written by this physician who heals her patients by returning them to the diet that would’ve been more matched to their ancestors . It’s a fascinating book but it kind of highlights this concept that once you take someone out of their natural ancestral eating protocol and put them into a typical Western diet, you tend to see obesity. But at the same time, dude, this doesn’t seem to be a huge surprise; this doesn’t really seem to be like a ground breaking explanation of obesity as much as pointing out the fact that “yeah, when we don’t eat our ancestral diet, we could tend to get fat.” So when it comes to that, I think that delving into the brain is something that gets a little bit more intriguing, and in that sense you start to talk in the book about what type of foods we actually get attracted to and why these Western diets have such a high propensity to make us eat more. And you start that by talking about why kids like things like ice cream and Brussels sprouts, especially with regards to this part of the brain called the ventral striatum, why that is. Can you delve into why we actually crave things like ice cream versus Brussels sprouts?
Stephan: Yeah, absolutely. And I wanna first give a little more of a zoomed out perspective and just say that there are certain properties of food that we’re attracted to but there’s a bigger picture where the brain also factors in things like convenience when it’s engaging in its decision-making process around eating. But obviously the physical and chemical properties of food are very important to our motivational level with regard to food. And this makes a lot of sense because certain physical and chemical properties would’ve been a lot more valuable to our ancestors than others in terms of their survival and reproductive success. Reproductive success is the currency of natural selection, and so things that increase reproductive success are going to be selective over evolutionary time.
And so basically, genes that make you better at seeking the things that make you survive and have much babies, and I’m talking about our distant ancestors here, are things that are going to get passed down and reinforced. And so this really gets at the heart of the issue of “what is it exactly about food that we want? What is it exactly about food that motivates us, that makes us go after it?” I think this is a very fundamental question that I haven’t seen answered in any other kind of general audience book. But this is something that we know quite a bit a lot about in science and basically how it turns out is that the brain is hard-wired. And this is the brain, I’m talking about all humans, that these are things that are common to all cultures no matter where in the world you grow up, you’re gonna be interested in these particular food properties. The brain is hard-wired to seek certain properties in food and these include sugar, fat, starch, salt, protein, and the amino acid glutamate which is that umami, meaty flavor that you get in bone broth and cooked meat and soy sauce and MSG.
Ben: Right. Protein is in there, really?
Stephan: Yeah, yeah; proteins, I think it is. And so the reinforcing effect of protein hasn’t been directly demonstrated in humans but it has been demonstrated in rodents.
Stephan: And I think it’s likely that in humans too, and data in hunter gatherers support that as well because they definitely are motivated by protein somewhat independently of total calories. That’s actually seems to be the second biggest motivator for them when they’re choosing their food resources; number one is calories, number two is protein. So I think there is some wiring there around protein.
Ben: The only reason I question that is because in the absence of things like the umami flavor and the fats and salts and the sugars, sometimes protein can seem a little bit bland.
Stephan: Yeah, I agree with that. However, I think once you start to combine protein with salt, like salt and meat, you get a food that actually is associated with craving in a pretty high percentage of people, especially men. So I don’t know that a lot of the proteins that we eat are pretty natural, like meat is a pretty natural food; pretty ancestral food, so I don’t know if meat really can kind of rise to the level of “addictiveness” that you’re gonna see with brownies and cakes and that sort of thing. But I think it definitely has a motivational value for us, and especially meat does; I think that’s very hard-wired.
So anyway, our brains are literally wired to look for these specific properties in food, and those are food properties that actually spike dopamine and a part of the brain called the ventral striatum. And the ventral striatum is really important; it’s a key part of the brain for motivation, learning to be motivated over time, as well as pleasure. And this is also known as the nucleus accumbens. Basically when dopamine spikes in your nucleus accumbens, that makes you motivated to go after whatever it was that made the dopamine spike. And so if you eat a food and there’s tons of fat and sugar in it, for example, your dopamine’s gonna start to spike and that tells your brain “wow, this thing that you just ate is awesome, is a really great source or fat and sugar.” And so what your brain’s gonna do as a result of that dopamine is it’s gonna collect all the sensory information that was associated with that food you just ate.
So it’s gonna say, let’s say it was a brownie, it’s gonna remember the smell of the brownie, it’s gonna remember the appearance of the brownie, it’s gonna remember where you got that brownie, it’s gonna remember who you were with, it’s gonna remember the name of maybe the restaurant where you had it. And all those things are registered in your brain, and because of that dopamine, those things become a motivational cue. Because of their association with that dopamine that was triggered by that sugar and fat, those things become motivational cues in the future. So the next time you smell that brownie smell coming out of the oven, it’s gonna start spiking your dopamine again and you’re gonna feel craving; you’re gonna feel an instinctive motivational drive to eat that food, which we call cravings, and then it’s maybe difficulty for you to stop yourself from eating it at that point.
So basically we learn to enjoy, so there are innate preferences, there are these basic food properties that we’re hard-wired to enjoy, and then there are learned food preferences about the flavors and aromas and textures of the food we repeatedly associate with those innately preferred preferences. And so everybody in the world loves fat and sugar, but not everybody loves the flavor and aroma of traditional Szechuan cooking in China. And not every Chinese person is gonna like the smell and taste of stinky French cheese. Those are things that we acquire over our lives by virtue of their association with those reinforcing properties.
So for a kid, if you think about, especially for children who haven’t had a lot of time to form these preferences… For example, some people as adults like kale. The reason we like kale is because we had it with fat and salt so many times that our brain has made that association, but if we never put that salt on it, we would never develop that preference and it would just taste like bitter crap. Because the brain doesn’t care about vitamins and minerals; those are not hard-wired motivational properties. You can’t reinforce behavior by adding vitamins and minerals to food; you can’t taste vitamins and minerals. The only exception is sodium chloride; that’s the only essential micronutrient that we can actually taste, that we can actually perceive. And so basically, the reason kids like ice cream is that it has everything that the brain is hard-wired to enjoy. It’s very calorie dense, it has lots of fat, it has lots of sugar, doesn’t have any bitterness.
Ben: Right, and that’s what causes the dopamine release in the ventral striatum; that’s what actually makes a food addictive, is its ability to cause a ventral striatum release?
Stephan: Yeah, absolutely. And when you have these properties that are combined especially, the fat and the sugar together, in a really concentrated form, you get a lot of dopamine release. And so it’s pleasurable on the spot but all that dopamine also reinforced your behavior so that in the future, it’s gonna be even harder for you to refuse that food. Your behavior is gonna be getting pushed on a non-conscious or minimally conscious impulsive/instinctive level that craving; your behavior’s gonna be getting pushed into that ice cream. But a kid has very little motivational drive for vegetables, I mean kale, Brussels sprouts, broccoli; these things are notoriously unpopular with kids because they don’t contain those innately preferred properties that the brain’s looking for that drive dopamine, that drive pleasure and reinforcement and motivation and cravings.
Ben: Right, so one example that you use in the book is chocolate because that has a ton of these things that cause that dopamine release, right? It’s got calorie density and fat and carbs and sweetness and then you even mentioned how it has theobromine which is a mild stimulant like caffeine and that’s why so many people get, not coffee cravings but rather chocolate cravings because it’s a perfect example of one of these foods that causes the dopamine release. And one of the things that you talk about as well is the idea of sensory specific satiety, meaning that this is also related to, I think the way you explained it is, how many different sensory properties a food has. And you actually tie that into how we can do a better job not overeating at the buffet. Can you get into the little trick for the buffet and what kinda science that’s based on?
Stephan: Yeah, yeah. Absolutely. So slight clarification, it’s the number of sensory properties that a meal has rather than a specific food.
Ben: Okay, got it.
Stephan: And so, basically the way sensory satiety works, and this relates to a very basic property of the nervous system called habituation. So essentially when you’re first exposed to some stimulus, like let’s say you’re driving to work and you see a new billboard that they just put up last night. You see it for the first time, might catch your eye, maybe it’s kind of interesting, maybe it’s got a good looking member of the opposite sex on it, and it catches your eye…
Ben: Or a bar of chocolate.
Stephan: Or a bar of chocolate. And it catches your eye but the next time you see it, if you were shown that 25 times in a row, you’re gonna pay less and less attention to it. That billboard is conveying less and less information value to you each time you see it. And so that’s a property called habituation where when you’re repeatedly exposed to the same stimulus, you’re going to respond to it less and less. And this is something that you see all the way to jellyfish, which are very, very distant cousins of ours. You can poke a jellyfish and it’ll react, and then if you keep poking it in the same way over and over again, each time you poke it it’ll react less and less and less. It basically gets habituated to the stimulus. This is a very fundamental property of the nervous system that’s very useful that we see all the way up to humans. And so the way that that works when we sit down to a meal is that we actually become habituated or satiated by certain specific food properties, certain sensory properties. And so for example, if you’re sitting down at the table and eating something with a salty, protein-y flavor profile, you can eat until you’re completely full on that steak, but that doesn’t mean you’re gonna be full and not wanna eat a potato. And eating that potato doesn’t mean you’re gonna be full and not want to eat a piece of dessert afterwards, something that’s sweet.
So this is why we overeat at buffets basically, because buffets have an almost unlimited amount of sensory variety. So you can eat your full on one item but if there’s ten different items on your plate that you have to eat your fill of, you’re gonna end up eating a lot more total calories. And this has been demonstrated in randomized control trials a number of times; basically the greater the number of unique foods, unique in terms of their sensory properties that we have at a meal, the more total calories we’re gonna eat. And we don’t even feel more full, but we do it anyway just because fullness isn’t just about the number of calories you ate, isn’t just about the volume that you ate; it’s also about how your brain is perceiving your intake of specific sensory property foods.
Ben: Got it. So the idea then would be if I were at Whole Foods and I didn’t to overeat at a place like Whole Foods, what I would do is try to choose two or three items to reduce variety because once you introduce variety, you decrease satiety. Meaning I could eat 1000 calories of two to three different foods like the sweet potatoes, the broccoli and the roast chicken, whereas I could eat 2500 calories of like seven different foods. The satiety effect would be similar but by having a wider variety of foods, it would take a longer time for me to feel full?
Stephan: Yeah, that’s exactly right. And that’s kinda the strategy that you can adopt when you go to a buffet. You just select a few things that you wanna eat, that you think will make healthy and satisfying meal, and you stick to them.
Ben: Yeah, and that’s what I do by the way. I walk through the entire buffet for Whole Foods; I walk everything rather than just starting and begin. Coz what happens is you put one thing on, it looks pretty good then you’ll see something that looks even better, you put that on. And by the time you’re done, you’ve got eight different things when you could’ve done a quick walkthrough, chosen your three top items, and just gone from there. And it does work when you just put a few things on, you eat far less.
Ben: And you beat that buffet effect that you describe in the book.
Ben: [whispering] Hey, I have a secret to tell you. I take this supplement every single night before dinner. I kinda feel lost, kinda like I don’t have my cell phone on me if I travel and I don’t have this supplement. No, seriously, I’ve been taking this supplement for three years when I do my fasted blood glucose levels, they’re at like 70s and 80s. My hemoglobin A1C which is a three month snapshot of my blood sugar levels, super low. My blood sugar is stellar; my blood sugar’s awesome. I might have some faults about my personality and my body, but my blood sugar is not one of those. I attribute a great deal of that to the fact that I do just as the people of Okinawa do, and I use what’s called bitter melon extract before every meal derived from wild bitter melon.
I also have extremely low liver enzymes, just saying and just bragging about my liver and my blood sugar all day long. My liver enzymes are super low because in addition to this bitter melon extract, I also take rock lotus extract. The two of them combined in one capsule beats the pants off metformin in my opinion because you don’t get the risks of metformin like lactic acidosis, hepatotoxicity, sleep issues and a lot of those things. But it lowers your post-meal blood glucose like gangbusters. Also, fantastic for healthy liver function because I may or may not have a glass of wine most nights. So it’s called Kion Lean, K-I-O-N Lean, and you can get it over at GetKion.com, just like it sounds. Kion is K-I-O-N, GetKion.com.
Kion is my company and what I do at Kion is I create amazing formulas, amazing supplements if I don’t say so myself. Anything I want to make that I find in my own research to be helpful, I put it up there for you. It’s called Kion, GetKion.com and what I just described to you was the supplement called Lean; one of the few things I take every day. Pop two of them every night before dinner, or anytime else I’m putting sugar into my bloodstream. So check it out, Kion Lean.
Ben: Now you also go into something I found fascinating, what non-industrial diets have in common, and it’s related to this limited variety of foods. Can you go into what it is that non-industrial diets have in common and why that’s helpful here when understanding why we overeat?
Stephan: Yeah absolutely. So there’re three properties in non-industrial diets that I highlight in the book that I think are important differences between non-industrial and industrial diets that are very relevant to food intake behavior, especially calorie intake. And the first one is that non-industrial cultures tend to have a limited variety of food, and this actually comes as a surprise to a lot of people because it’s kinda counter to the prevailing narrative that everything we eat is made out of corn and soy. And if you look at hunter-gatherers, they ate 100-200 different types of food around the year. But I think if we take a closer look, that argument kinda falls apart, and so this is something that I became aware of when I started studying non-industrial cultures. I’ll use as an example the Kung San of the Kalahari Desert. These are very well-characterized hunter-gatherer culture. I’m actually not sure that they’re really hunter-gatherers anymore but at the time they were characterized, they recognized 105 plants as edible.
So they would eat a high proportion of those in a typical year, so that’s a lot of different types of food but only 14 of those actually formed the bulk of their food intake. And of those, actually half of their year-round calorie intake came from one food: the mongongo fruit and mongongo nut; it’s a fruit with a nut inside. And so actually their diet, and especially on a daily basis, on any particular day they weren’t eating a great variety of foods. They would just have a few different things: there would be meat, maybe there would be some mongongo nuts, maybe there would be some fruit. But they weren’t eating 100 different things every day. In each meal, there are only a couple different things, whatever you could find, it’s inefficient to go looking for a million different things. And they would share so there was some variety but they weren’t eating 100 things every day or even every week. They’re eating, mostly, just a few things. And this is what you see in almost every non-industrial culture. Basically they narrow in on the most efficient way to feed themselves, which tends to be one or a few key food resources and then they focus on those.
So like, if you look at Polynesian islanders, they ate a lot of taro, they ate a lot of yam, they ate breadfruit, they ate coconuts, and then that was the bulk of most of their diet. And then if you look at agricultural populations, most of their diet comes from one or two grains like corn or sorghum or rice, in some other areas maybe there was cassava or potatoes. And then they would supplement that with things like beans and meat and seafood and game. But most of their diet was coming from one or two foods, so what you see is if you really look at the day-to-day eating behavior of non-industrial cultures, the variety in their diet is actually rather limited. And then the second point I’ll make is that if you think that our diet today is limited in terms of its variety, I encourage you to walk through the produce section of a grocery store and count the number of different species you can find in the produce section that’s available year-round in a grocery store. There’s a very large variety especially now that we can get anything at any season; there’s a very large variety of different foods, and that’s just the produce. It is true that a lot of our processed food comes from corn and soybeans and we eat a lot of processed food, but you find the same thing in non-industrial cultures where most of their calories are coming from just a few staple foods.
So I think that actually, especially if you’re considering the sensory variety, coz even from the basis of corn and soybeans, our industrial food system has been able to produce and incredible variety of sensory experiences. And so even though they might be made of the same ingredients, you have all these different flavor profiles that are coming out of it. So on a sensory level especially, there’s quite a bit of variety in our diet.
Ben: Yeah, and that’s one of the really interesting things that I’ve noticed among a lot of people who are really successful maintaining lean body mass or not overeating is similar to me, not to toot my own horn, but I eat the same thing for breakfast almost every morning. Same thing for lunch almost every day. Now that’s not to say that there’s not some amount of dietary variety; like in the winter, my lunch is more like cooked vegetables with some fats and oils, and in the summer it’s more like raw, cold vegetables. So I am into the seasonal eating thing, but it’s one of those deals where I just limit the variety and when I do that, when I don’t have twelve different things that I’m piling onto a plate, I’m able to eat far less. And it looks like, when you look at a lot of these non-industrial diets that you just described, they indeed not only have that limited amount of variety but it looks like, based on what you say, they’re not adding a lot of refined starch and sugar and salt and concentrated fat to the meal so they’re not making them extremely palatable.
And then they use few cooking methods, that was the other thing you went into was they’re using like two or three different cooking methods rather than thinking they have to outfit their kitchen with freakin’ like a sous vide and a steel cooking pan and a blender and a dehydrator and a gas stove. All these different cooking methods, and so the take away message from me was that “hey, if you’re having difficulty overeating, have simplicity, don’t buy every kitchen tool on the face of the planet, buy a limited variety of foods, don’t have a ton of salt and spices on hand, and simply eat in almost a little bit of a bland way.” And based on the research from what you’re saying, this ventral striatum, that can be a very, very good way to keep yourself from overeating, correct?
Stephan: Yeah, yeah, I think so. And I mean, yeah, I think simplicity is really the key and our ancestors ate in a very simple way, they prepared food in a simple way, and they didn’t have a lot of ways to embellish it. And I think that that is an important but often overlooked aspect of ancestral eating. And I wanted to expand a little bit on this thing that you brought up, so basically these three properties. You said the other two which is that they have a limited ability to concentrate the reinforcing properties of food, so that things that the brain is in tune with, and third that they use fewer cooking methods. I think this limited ability to concentrate the reinforcing properties of food is really important.
So I like to use cocaine as an analogy, and I think drugs are actually a pretty good analogy here because drugs of abuse literally act through the same pathways that food does when it drives our motivation and when it makes us crave. Those are pathways that evolved to get us to seek good things like food and sex and everything else that are kind of hijacked by drugs. But I think drugs make a really clear analogy that helps us think about this. So for cocaine, that comes from the coca plant which is indigenous to South America, and it’s been used for thousands of years as a mild stimulant, appetite suppressant. People just chew these whole leaves, they just chew the leaves and that provides them with this kind of caffeine-like stimulant which is very low doses of cocaine is what it is, and that has beneficial effects just like caffeine has beneficial effects for us to stay awake and be productive and whatever. But then, if you take that property of the coca plant; if you take the “active ingredient” that spikes dopamine and you purify it, you get cocaine. And cocaine, it’s the same thing as just more pure and by technology we’ve been able to isolate that active ingredient that’s what our brain is looking for and then it spikes dopamine way more.
And then we’ve been able to further tweak it by free-basing it which turns it into crack which crosses blood-brain barrier and mucosal barrier much faster is if you’re faster hit and it’s even more reinforcing is you have faster higher dopamine spike. And then it turns this natural substance that is mildly reinforcing and useful into what ends up becoming a life destroying drug or can be a life destroying drug. And so I think the analogy extends to food where basically if you look at a whole piece of whole fresh fruit, that’s got sugar in it, that’s something that spikes dopamine, that’s something that your brain wants. Fruit taste good, right? But it’s not something you’re gonna like, “Poor John, and become obese ‘cause he ate too much fruit.” It tastes good but it’s not insanely good. And you know, compared to ice cream or brownie or whatever, most people would choose that over fruit.
Stephan: Just on the basis of pure visceral pleasure not in terms of thinking about the health impacts. But what happens when we take the active ingredient of that fruit? The sugar, the thing that spikes your dopamine, the thing your brain is looking for in a fruit. What happens when we take that and concentrate into pure sucrose? We have taken something that is useful constructive substance that spikes dopamine to a degree that we would have seen in our descent ancestors, and turned it into this highly dopamine spiking concentrated substance that we can add to food that basically spikes its dopamine potential as well as its motivating potential beyond anything that our ancestors would have experienced. And this is not surprisingly why these types of foods lead to addiction like behavior in a lot of people. And the concept of food addiction remains controversial but I think I mean there’s no doubt that certain types of foods and there are all foods that are very concentrated in these properties I was talking about earlier; these things the brain is hard-wired, demotivated by and to experience dopamine spikes from. Those are the foods that people experience addiction like motivational levels and addiction like behaviors around and I think it’s because basically our brains didn’t evolve to handle the massive dopamine spikes that happen when you isolate and purify those active ingredients and just like blast your brain with them. It’s very analogous to cocaine.
Hunter-gatherer population, our ancestors simply didn’t have the technology to purify and refine the active ingredients in food like sugar, and salt, and glutamate the things that really spike our dopamine. They didn’t have the technology to concentrate those things and mix them together in the ways that we can today. So basically technology, as technology and affluence have progress has gotten better and better at catering to the instinctive preferences of our own brains and we're so good at doing that now that we are creating destructive behaviors in ourselves and destructive levels of food motivation.
Ben: Now one of the things that struck me as potentially paradoxical was you go into the fact that despite having a large amount of simplicity and few cooking tools, and a lot of salt and sugar and fat added to the diet, the idea of moderation in eating is actually something form to hunter-gatherers when we see them eating, engaging in downright gluttonous habits. Can you go into why that is like how our hunter-gatherer neighbors can be gluttonous and yet not obese?
Stephan: Yeah, absolutely. So I think this kinda take us to a different angle that we can use to address the question what is it fundamentally that the brain is motivated by about food. And we can look at this from a broader perspective now and say, it’s just not about the food properties but it’s about how we acquire those foods in the environment. How much effort and how much time are required for us to obtain those foods. How does that affect our motivational level? And how does that affect the big picture of our decisions to eat and our motivation to eat. And researchers have modelled this really remarkably in a variety of species using a discipline called optimal foraging theory and first they showed this in non-human animals that basically you can predict an animal’s foraging behaviour, an omnivorous animal that has a lot of potential things that could eat, you could predict what it’s actually going to go after based on a very simple equation, it’s called the optimal foraging equation. This is the value of a food item to that organism equal to the number of calories it contains minus the number of calories it takes to obtain and prepare it divided by time. So it’s the calorie return rate of that food. And this is very similar to basic economics equation for profit maximization. It’s just the basic return rate calculation and what you see is that animals behave according to that equation. And one of the animals that behave according to that equation is human hunter-gatherers. And so you can actually to a pretty remarkable degree predict their foraging decisions based on this equation.
And so, what this equation predicts is some pretty interesting things and one of them is that if a food contains a lot of calories and it doesn’t require to obtain and it doesn’t require a lot of time to obtain, so if the calorie retain rate is very very high, that food is going to have a very predicted value to that hunter-gatherer. And so it’s going to create a very high motivational state and that hunter-gatherer will potentially gorge on that food resource. So basically it’s easy calories, it’s opportunism. When you have the opportunity to get easy calories, you’ll gonna take advantage of it. That would be more colloquial way of putting that what the equation implies. And that’s exactly what we see. So the anthropologists that I spoke to, most of them were describing this sanely gluttonous incidence that they observed among hunter-gatherers when they had this sort of like easy calorie windfall. So people chugging a quart of honey, like imagine that chugging a quart of straight honey…
Ben: Yeah, seriously that’s almost gag reflex and there’s a lot of honey up in our pantry right now, but what you’re saying is that they would like give up a hunt for an animal to wander up to the site of a path and eat copious amounts of honey without ever looking at the calorie label or worrying about like let’s say, “fructose is not an amount of ketosis or something like that”.
Stephan: No absolutely not. It didn’t matter what it was. Whether it was fatty meat whether it was honey, whether it was fruit, if there was easy calories to have, they would take advantage of it and there was no cultural taboo around overeating. Like overeating to hunter-gatherers is good. There’s not any quilt associated with it, there’s not any cultural breaks on it. When they have the opportunity to gorge themselves, they take that opportunity and they do it with relish. And when you think about it and you ask the question why aren’t these people obese, and there’s only one answer to that and at least on the most basic level and that is that those gorges are balanced by other periods of time when they’re probably not getting as much calories as they would want. So on balance, they’re in energy balance but that’s only because they’re taking advantage of these opportunities to gorge. If they weren’t taking advantage of that, they would probably not be maintaining energy balance.
Ben: So it’s basically just this entire concept of feast and famine.
Stephan: Exactly. So, how do you deal with famine? You have to feast. And so, I’m using the word famine but most hunter-gatherers don’t experience very bad famines but they still have variability in their calorie intake and in how easy it is to obtain those calories. And so we know that calorie intake is a fundamental, one of the most critical drivers of survival and reproductive success. One of the main reasons for that is obviously your calorie needs and your nutrient needs go up when you’re pregnant and also in childhood, your immune system activity is very very dependent on your calorie supply. The immune system is a calorie hog and infectious disease in non-industrial settings is a huge cause of infant and childhood mortality; like one-third to one-half depending on society if they don’t have modern medicine, you’ll gonna lose a third of your kids to disease and a number of calories you’ll getting has a huge influence on whether they’ll gonna survive or not.
And so, basically taking advantage of this opportunity to gorge is good for them. It’s not bad for them like it is for us. It’s good for them. It increases their ability to survive, it increases their ability to bear children and have those children survive. And so basically they are presumably wired in some sense to favour, to take advantage of these opportunities when they present themselves. And I think that this is a wiring that goes pretty deep, I mean, that we see the exact same thing today like what’s the scenario. Imagine the scenario today that would be maxing out the optimal value or the optimal foraging equation. It would be like free pizza or free food in general, like how fast is free pizza disappear. It’s gone, like people will stuff themselves with it even if they’re not dead hungry ‘cause it’s like this amazing opportunity to get tons of calories at no cost.
Ben: Right. That’s one of the issues that you get in to the book is it so easy to fall in to this habit or this ancestral mechanism that our hunter-gatherers would follow even though we’re not actually starved but we’re still responding in a way that we would if we did have periods of famine. Like winding up in a buffet or being in a situation where we’re just present with a bunch of free food. Which happens to me like ‘cause I occasionally speak in an event. I’ll walk in my hotel room and they’ll just be plates and plates of food and they’ll say, “Oh, we’ll gonna cover all incidentals. So order anything you want at the hotel menu,” and all of a sudden I’m presented with that scenario where my ancestors wants to kick in and say, “All right, there’s the honey pot, right? Dive in.” But you have this concept that you present in the book called “Episodic Future Thinking” to reduce the intake of like tempting in calorie-dense food when they are presented to us in that type of scenario. Can you go in to what exactly that is and how it works, like how we can actually use that in a practical way?
Stephan: Yeah, absolutely. So this is some research that I came across by Leonard Epstin who’s one of the researchers. He’s a professor at University of Buffalo, he’s one of the researchers who contributed quite a bit to the book. Really fascinating guy and fascinating work. So one of the topics I talked in the book is how our decision making process frequently pits our present selves against our future selves. And this is something called… well, yeah, it relates to a property called time preference.
So generally, we tend to short change our future self in favor of our present self. I’ll give you an example: if you are going to eat a donut let say, I don’t think anybody thinks donuts are healthy. The reason we eat donut is because we are going after that pleasure value of eating donut. That is a benefit that you experience right now, whereas the cost of eating that donut such as the financial expenditure and the future effects on your health and your waistline, those are all things that your future self incurs. And so you’re basically making a decision to favor your present self over your future self which might be you in a bathing suit next summer or you whether or not you have end up developing diabetes and having gone on medication and additional expense and all that, et cetera. Those are all cost you your future self. Basically, most of us have a time preference for our present selves. Actually all of us do pretty much to varying degrees, and what you see is that people who have a very strong time preference for their current selves over their future selves, they tend to weigh more, they tend to have more credit card debt, they tend to being in poor health, basically anything you wanna look at that has to do with delaying gratification, those people are going to have poor outcomes. And this makes a lot of sense because actually hunter-gatherers lived in a very uncertain world. You didn’t even know if you’re gonna be alive in five years. So why would you do something now, why would you give up something now that would benefit you in five years if you don’t even know if you’re gonna be alive? And also it’s just very uncertain whether or not you’ll gonna be alive, you can’t really control your life that well. Like you can’t make deals.
Today you can put money away in your retirement account and you can have reasonable amount of confidence that that money is gonna be there in 30 years, I mean, that’s crazy, like hunter-gatherer can’t make deal with somebody and expect that person to pay them back in 30 years. There’s not that level stability in their lives, and so basically it makes sense to have a time preference because the future is uncertain but the problem is that that’s been so wired into our brains that time preference that today we short change ourselves in a world where it make sense to have less of a time for preference.
Today we have long lives, we live in a relatively stable society, there’s a lot of accountability. It make sense to care a lot about your future self but we don’t because we’re not really hard-wired to do that. And so one way to increase our ability to value our future self, to increase our kind of like intuitive ability to make decisions that favor our future selves is this technique he talked about called Episodic Future Thinking. And it’s really really simple technique. It’s a fancy phrase that just means thinking about the future before you make a decision.
So if you’re about to make eating decisions, let’s say you’re at a buffet or you’re in a coffee shop and there’s pastries behind the counter that are tempting. If you think about something that’s going to happen to you in the future, so think about something positive like what you’re going to do on your upcoming birthday or some positive event that you’re thinking about in the future that you’re planning about in the future. It kinda revs up that part of your brain that wait for the future intuitively and it increases your likelihood of intuitively making decisions that value your future self, that don’t short change your future self. And so it’s been shown to work in an eating context so with… I think the studies may have been done in women with obesity as well as children when they use this episodic future thinking, it helps them make better food choices and it helps them eat healthier foods and eat less food in general.
Ben: Yeah. And the other interesting thing that I used that somewhat similar is… it might have be somewhat similar but it’s kind of this objective way to look at things is, I imagine that I’m in a movie and that people are watching me in the movie rooting for me as the protagonist in the movie to make the right decision, right? So if I’m standing in front of the refrigerator at 10 PM and I really want to eat a bunch of food but no, I’m not hungry, I’ve no have not enough calories, I think, “okay, let’s watch a movie. I’m sitting in the theatre and I see me on the screen standing in front of the refrigerator…
Ben: I’m gonna be rooting for me to go get a good night sleep and not stuff face so that I can stay lean for my competition and place high in a race, or so that I can have the body I want or so that I can avoid the inflammatory effects of high blood sugar while I’m asleep. And once I think about that it seems simple and stupid but for me it actually works. Imagining that I’m actually an actor in a movie and that my role is to behave so to speak from like a calorie intake or a cheating standpoint, but this idea of imagining in the future is another one that it appears based on research actually is pretty compelling.
Now, there are few other things that you get into in the book that I found really fascinating. First of all, it appears that when you’re talking about the ventral straitum, and the release of dopamine from a lot of these highly palatable foods that we get exposed to, there’s also another area of the brain that is the actual satiety center that causes us to feel full and that they’ve actually identified this somehow in rats. Can you talk about the lesioned rats in the book and what this satiety center and the satiety factor is?
Stephan: Yeah, absolutely. And I start off by saying that I think the term satiety in this context is a little bit of a misnomer but I use it in the book because that is what it was called historically. And basically what they found… so the first hint of this is there was this German professor named Bernard Moore who in 1839 published a case study on this woman who had spontaneously developed massive obesity among other symptoms. And she was taken in to a hospital and she was just so fat that it was really striking in the case report that he went on and on about how remarkable the quantity of fat that this woman had on her body, and then he did an autopsy of her after she died. And he looked on her brain and he found that she had a tumor in a part of her brain called the hypothalamus. And that was really the first evidence that we know of that the hypothalamus plays a key role in regulating body fatness. And at this point in 2017 we have massive amount of evidence about this. But that was really the first thing and then that research continued through lesions studies where people would go in and they would destroy a certain parts of the brain in different research animals and they could kind of cross checked this with human patients who naturally spontaneously develop tumors and other forms of damage in parts of the brain, and they found very similar effects.
But basically there was a part of the brain called ventromedial nucleus which is in the hypothalamus that when you lesion it animals would become enormously fat. So they would begin overeating tremendously and become enormously fat and because destroying that makes animals overeat and makes them fat, they called the ventromedial nucleus the satiety center. So basically get rid of it to get fat so they were saying, well, maybe the normal function of this is to suppress or constrain body fatness and appetite. And basically there were a number of other models of obesity that emerge after that so some of them were other lesion sites, some of them were genetic models of obesity that emerge spontaneously. And basically people started to figure out that this satiety center in the vMN and nearby areas was responding to a circulating factor basically the reason those animals got so fat is because they lose their brains, their hypothalamus lost the ability to sense some circulating factor that was regulating body fatness. And this research suggested that furthermore not only was there a factor which they called the satiety factor that was in circulation that was affecting body fatness, furthermore that it was really really powerful. I mean the effects that they would get were huge like animals that had a disruption either in the satiety factor or in its receptors or in the brain regions where it’s received would become massively massively obese, whereas conversely if there was an excess of this stuff, animals would just lose all visible body fat and sometimes die of starvation.
And so this was clearly a very central system in the regulation of appetite and body fat. This is clearly at the heart of why people had different levels of body fatness, why people eat different amounts, and research has continued to support that conclusion as we’ve understood more and more about this system. It turns out the satiety factor is a hormone called leptin. It’s a protein that’s produced by fat tissue in proportion…
Ben: So leptin is the actual chemical that is called the satiety factor.
Stephan: Yeah. That was what it was called historically before we knew what it was. So people knew a lot about leptin even before it was discovered. All this stuff that I was just talking about, about the effects on appetite and body fatness, that was all understood even before we had identified what the satiety factor actually was but we knew was in circulation I say, we, this was before my time as a researcher, they knew it was in circulation, they knew it was acting in the brain and they knew it was acting to powerfully constrain body fatness and appetite.
So leptin is produced in proportion to the size of fat stores and it’s the signal that tells the brain how much fat you are carrying. And basically its job is to prevent you from losing fat, prevent you from starving. And so if your body fat levels starts to drop from your so called set point or the level of body fatness that your brain kinda “wants to maintain”, it will initiate a starvation program and that includes ramping up your appetite, ramping up your cravings, reduces your calorie expenditure, it might make you feel sluggish and cold. These are symptoms that many people are familiar with if they have lost a substantial amount of weight. And so, basically that starvation response is what kicks in in a really extreme form when you have animals that either don’t have leptin or can’t respond to it. So basically even though they are incredibly fat, their brain thinks they’re starving because their brain can’t detect any leptin so they think they have no fat and they’re dying of starvation. And so, essentially it kicks in this huge starvation response, they get really hungry, they get cravings, they can’t get full, their calorie expenditures constrained, and so they continue to put on more and more fat and have this elevated appetite.
Ben: And so in humans what would be the equivalent of a vNM lesion in rat, like how would that scenario be created in the human? ‘Cause obviously humans who really don’t have lesions?
Stephan: Yeah, right. So there’s couple different ways: one way is you can have tumors, this is called hypothalamic obesity. So tumors that destroyed that area can cause very similar effects to what we see in vNM lesioned animals. You can be born genetically without leptin, there are few people who have been identified that lack leptin so those are like genetics, models of obesity I was talking about earlier, these people are incredibly obese, they cannot feel full and they cannot really slim down like it’s almost impossible to cause and to lose weight. I mean, these are kids who are so fat that without treatment they can’t even walk at age eight they’re in wheelchairs like incredibly fat.
Ben: Oh, wow.
Stephan: And all they think about is food. As teenagers, they’re not really interested in girls or dating, or any of that. They just wanna talk about recipes, they wanna talk about food. Food comes to dominate their mental lives which I think serves to illustrate how deeply rooted these systems are in the brain. And so those are the extreme cases, those are cases of brain damage or genetic mutations that really like throw a wrench in the whole system but I think that…
Ben: So why couldn’t we just for those people just give them a whole bunch of leptin?
Stephan: Well, you can for kids that lack leptin, you can and they do and it helps them a lot. If you give them leptin they slim down and their food intake comes under better control and they turn into pretty normal kids. But the problem is that in people with typical obesity, there’s no leptin deficiency. People with typical obesity aren’t lacking leptin. Their system, everything is there. Their hypothalamus is there, their vMN is there, there’s not any like massive damage, their secreting leptin from their fat tissue, the amount of it in circulation is proportional to their body fatness just like it’s supposed to be. The problem is that their brain is not responding to that leptin as effectively as a person who’s lean. So their brain basically have this condition that we called leptin resistance. So their brain just can’t hear the leptin very well. So it takes more leptin and more body fatness for the brain to feel like it’s not starving and for the brain to takes more leptin to the brain to restrain that starvation response that they would kick in if it thought you were starving.
And so basically your comfortable level of body fatness, the level that you settle at if you’re not really doing anything special to try to change it is going to be higher when your brain can’t hear that leptin very effectively. And we know that animals and humans that are obese that have obesity require a higher level of leptin to avert, to stop that starvation response and so they literally have a higher set point, it’s like turning up your thermostat, it’s like turning up the heat on your thermostat, your thermostat will defend that higher temperature subpoint.
Ben: Oh yeah. That’s why the people who were on the Biggest Loser regained all their weight because their bodies actually wanted to be at that original weight that they were at?
Stephan: Yeah, I think that’s a great example and I talk about this a little bit in the book. And there’s some research on this too but I think it’s a great example because it’s a really extreme example that really illustrates it clearly. So if you look at people on the Biggest Loser, they’re losing like hundred pounds, sometimes more, that’s a lot of fat and it takes as anyone who has seen the show can attest to you, it takes a tremendous amount of effort on their part to get there. But if you follow them up after the show what you find is that almost all of them regain a substantial portion of that fat. Most of them regained most of it if not all of it and this is not just one or two people, this is almost all of them are regaining most of this fat. And so, if you look over a period of one or two years and if you see the interviews with these people it’s like, if you read the interviews, it’s like they’re just devastated. I mean, they feel very frustrated, they feel that they are failures, they feel like they were continuing to try, it’s not like they just said, “oh, the shows over. I’m gonna start eating tons of pizza.” Like they wanted to maintain that lower weight. They made efforts to maintain that lower weight and those efforts were not effective, and I’m not saying they weren’t effective at all but they were insufficient to prevent substantial fat regain.
And so, I think that this really illustrate the fact that a person who starts off with obesity and slims down to a lean level is not physiologically and neurobiologically the same as someone who is naturally lean. The person who started off with obesity is going to have a strong tendency to regain because they’re generally going to be below the set point of their hypothalamus and they would have to fight a very strong starvation response to maintain that fat loss.
Ben: Now in a case like that would something like sensitizing one to leptin be one appropriate strategy to help to maintain the weight that you’ve lost? I mean, there’s guys like Jack Kruse out there for example that has a protocol called The Leptin Reset Protocol which is like a lot of protein with breakfast and not skipping breakfast, avoiding snacking, doing things like cold thermogenesis, using LG prioritizing sleep, messing around with light and water and circadian rhythms. His whole protocol kinda spelled out for that type of thing but would skipping one sensitize as possible to leptin be an appropriate for a strategy, for a scenario like that to avoid returning to that set point that your body wants to be at after you’ve lost weight?
Stephan: Yeah, absolutely. I mean, I think that leptin sensitivity is really the key thing that we’re going after but it’s also the thing that is very hard to know how to affect. And all those things that you just mentioned that are part of Dr. Kruse’s protocol, I’m not aware of any evidence that any of those effect leptin sensitivity. In fact I’m pretty sure there is no evidence.
Ben: Yeah. I don’t think there’s a lot of science and research behind that. I know that he works for people to lose weight and I know a lot of people who do lose weight seem to keep it off. I was just hanging out with relatively well-known guy Rick Rubin, like the Columbia records music producer and he’s dropped down from like 400 lbs. and kept it off relatively well and the guys actually does a lot in terms of… and he’s been on the podcast before talking about this maintaining very normal circadian rhythm and he does like sauna and cold treatments every day. And he even uses special blood sugar stabilizing supplements like bitter melon extract and cinnamon, and apple cider vinegar, and pulls out a lot of stuff but has successfully not just kept off weight but continuous to lose weight and I feel that a lot of those type of things seem to affect leptin.
Stephan: Yeah, that’s awesome. I mean, first of all that’s an impressive accomplishment and there are people who manage to do it and I think when I start talking about this stuff, I think it tends to come across doom and gloom to a lot of people like it’s hopeless, there’s no point even trying. That’s really not the message I’m trying to convey. I think that there are a couple of things to consider here. There are going to be people who are a typical in any situation and for any diet you can find that one person who lost a million pounds on the diet, that guy Jared lost, I don’t know how many pounds eating Subway’s sandwiches and walking around. That doesn’t mean everyone’s gonna lose 200 pounds eating Subway sandwiches every day. But for any diet you can find extreme responders that doesn’t necessarily mean that that is going to be the typical response for that diet, for that lifestyle. And I think that there’s genetic variabilities basically every aspect of this body fat regulatory system and one of the things that’s probably genetically influenced is how hard that starvation response is gonna fight you when you start losing weight. So some people’s brain are gonna kinda shrug its shoulders and say, “hey, you know, I don’t really care that much. I make you a little bit more hungry but I’m not really that worried about it.” I think that’s not common but I think it happens. And then there are other people where it’s like they’re gonna have to claw their way to get every single ounce of weight loss and fight hard to maintain it. So I think there’s differences like that but you know, the other thing is that the body fat set point that your hypothalamus is gonna defend is not an immutable quality that can never change. So it’s not something like genetically fixed that you can never influence.
The set point is actually a flexible quantity that can be influenced by your diet and lifestyle. And I think this is where diet and lifestyle really comes in and coming back to some of those things that you mentioned associated with Jack Kruse, it’s not evidence to my knowledge that they impact leptin sensitivity but some of those things can impact the set point whether or not it’s vile up in sensitivity specifically. And one of those things that I think presents a pretty clear case is protein intake. Higher protein diets have been shown to suppress appetite and increase metabolic rate and particularly in people who are trying to lose weight and maintain a loss. And so basically what you see is that all of these hallmarks of starvation response such as increase hunger, increase cravings, reduced calorie expenditure, those things are all kind of blunted when you eat a high protein diet which I think gives… it’s not direct evidence but I think it’s pretty compelling in direct evidence that higher protein diets are affecting the set point.
And another thing I talk about in the book is kind of the palatability and calorie density of the diet. There’s a lot of evidence in animal models and some evidence in humans that diet palatability can have a large impact on the set point. So basically when we eat food that taste really really good, the brain is going to start actively defending a higher level of body fatness and if we eat simpler natural foods, your brain is going to actively start defending a lower level of body fatness. And I think that’s why we see a lot of people who when they improve their diet quality they will spontaneously lose weight. And it’s not a struggle, it’s not like I’m being counting calories and forcing myself to eat less, like they start eating a diet of whole natural foods, they’re still eating to satiety, they’re not feeling like they’re struggling or depriving themselves yet that fat is coming off naturally and comfortably. And I think that’s the situation you see a lot especially in people who switch to more unrefined and ancestral type of diet. I think a lot of people who have switch to the paleo diet have experienced this very thing that I’m talking about. And I think there are a few different factors that go into that such as the protein and the palatability and perhaps some other things.
Ben: Yeah. One other thing that you talked about in the book that wanted to make sure I wanted to make sure that we touch on and then I know that we’re kinda long in the tooth with the length of the interview but I wanted to make sure that we touch on this really quickly ‘cause it’s super relevant and it’s something that a lot of people I think know but haven’t seen the science behind, and that’s this concept of the stuff called dexamethasone which is a cortisol-like drug that’s typically use to suppress the immune system and you state that when you give dexamethasone to folks like kids for example, they start to eat like crazy when they get this cortisol-like drug put in to their body. And there’s something about stress and cortisol that causes overeating. What exactly is going on in terms of cortisol and excess calorie intake?
Stephan: Yeah, absolutely. So, as you said the cortisol-like drug can cause overeating and fat gain and particularly gain of abdominal fat which is the kind you really don’t want to gain. And corresponding to deteriorations and metabolic health, those are things to see in high cortisol state where there it is induced by a drug or whether it’s induced by a tumor in your pituitary actually which is the most common cause. And so, I think the thing that’s really interesting about this is that it relates back to the relationship between psychological stress and eating. As cortisols are really important stress hormone and what you see is that people who experience psychological stress when… so it’s different types of people you know, all our body respond a little bit differently to environmental inputs and challenges and so certain people when they’re psychologically stress they secrete a lot of cortisol, other people don’t secrete quite as much, [1:26:42] ______ who secrete a lot is that they tend to overeat when they’re stressed. So this provides a potential explanation for why stress causes overeating. Literally stress causes us to produce a hormone that then goes in to the brain and actually acts in the hypothalamus to reduce leptin sensitivity and that causes us to eat more and gain fat.
Ben: And so that’s the mechanism, is that when we talk about cortisol and we talk about leptin, the idea behind stress is that hypercortisolism can actually reduce your sensitivity to leptin. And so one of the strategies would be to actually engaged in either cortisol controlling type of strategies and I have a crapped on the podcast about that from meditation to yoga, to breathing to all sorts of different supplementation type of protocols and beyond but also to be aware that if cortisol is higher for an stressed out scenario, one of the worst things we would wanna do is be around highly palatable foods.
Stephan: Yeah, that’s absolutely true. Just two additional details to flesh that a little bit: one is that there’s still some uncertainty remaining about the cortisol overeating story, so I think it’s pretty convincing but I don’t wanna say that it’s 100% certain yet, I think we need more research on it. The second thing I wanna say is that it’s not necessarily the only mechanism that can be at play. We also self-medicate our stress by eating comfort foods and those foods literally dampen the activity of the neural networks that are responsible for the feeling of stress as well as the physiological effects of stress including that cortisol release. So when we eat ice cream and brownies and whatever our favourite food is that literally dampens the neural activity that causes stress and makes us feel better. And so, that’s another root is that one more stress we can tend to gravitate toward eating too much of unhealthy food just because it makes us feel better.
Ben: Got it. So as you get in to the book there’s an actual biological mechanism that draws this relationship and there’s so much more in here that we even didn’t take a dive into from more about the satiety factor to this special neuron that cause us to overeat. If you guys are listening in and want the compete 3D’s on everything going on in your brain when you eat food, you need to check out this book. So it’s called “The Hungry Brain”.
I’ve been taking notes as Stephan and I have been talking to everything from that book “The Jungle Effect” that I mentioned, to Stephan’s book, to this “ Leptin Reset” that I talked about by Jack Kruse, to my podcast with Rick Rubin and a whole lot more. So go to bengreenfieldfitness.com/hungrybrain if you wanna check out all that stuff, and when you’re over there you can also leave comments or questions for Stephan and I, and I’ll try and hunt down some answers for you. But in the meantime at least grab the book ‘cause it’s well worth the read and I certainly folded over a lot of pages like I mentioned.
Stephan, dude, thanks for coming on the show and sharing all this stuff with us, man.
Stephan: Thank you for having me. It’s good to be here.
Ben: Alright! Well, cool folks. I know that was a deep dive. Hopefully there’s not too much smoke coming out your ears, but again, check out the book. There’s tons of practical solutions in there as well. So, until next time. I’m Ben Greenfield along with Stephan Guyenet the author of “The Hungry Brain: Outsmarting the Instinct That Makes US Overeat” signing out from bengreenfieldfitness.com. Have a healthy week.
Although most of us strive to eat well and avoid weight gain, our behavior doesn’t always live up to our lofty intentions. The remarkable explanation, argues neuroscience obesity researcher and today’s podcast guest Stephan Guyenet, is that we’re betrayed by our very own brains, which drive us to crave and overeat food. In THE HUNGRY BRAIN: Outsmarting the Instincts that Make Us Overeat Guyenet deploys his humor, wit, and extensive research experience to explain the instinctive brain circuits that compel us to overeat. He shows how those circuits expand our waistlines and undermine weight loss, and how we can use them to manage our weight more effectively. Stephan Guyenet has put his finger on a critically important explanation for our global obesity epidemic: the human brain. Although it’s indisputable that the brain is the cause of overeating – since the brain is the source of all behavior – this disarmingly simple insight has never before been the focus of a general-audience book. THE HUNGRY BRAIN starts from the very beginning, uncovering how our (leaner) ancestors lived, both in recent history and the distant past. From there, it explores the brain circuits that kept us alive in that rugged world: those that drive our cravings, make our food choices, govern our appetites, and regulate our body fatness. And it explains how the genetic roulette that determines how these circuits are wired is a major reason why some people are lean and others are obese. Unfortunately for our waistlines, we no longer live in the world of our ancestors, yet our brains keep playing by the rules of a survival game that no longer exists. Advances in technology and affluence let us tempt our brains with seductive, convenient food more than ever before, and willpower bows before the force of instincts honed by millions of years of evolution. And once we gain weight, the brain works to keep us from losing it again. The result is a world that’s fatter than at any previous time in human history. THE HUNGRY BRAIN explores the brain in a vivid and accessible way, weaving in illustrations, humor, and unlikely scientific discoveries to bring readers inside areas of science that have remained off limits to a general audience until now. Ultimately, it leaves you with profound insights into how the brain works, how the brain drives us to overeat, and what we can do about it. So who is this guy? Stephan J. Guyenet, Ph.D. is an obesity researcher and health writer whose work ties together multiple fields of science to offer explanations and solutions for our global weight problem. He received a B.S. in biochemistry at the University of Virginia and a Ph.D. in neurobiology at the University of Washington. He is the author of the popular health website Whole Health Source (wholehealthsource.org) and he is a frequent lecturer on topics of obesity, metabolism, and diet history. During our discussion, you’ll discover: -Why what Stephan presents in his book is absent from all popular theories of obesity…[7:45] Eliminate fatigue and unlock the secrets of low-carb success. Find out how in The Low Carb Athlete – 100% Free. Sign up now for instant access to the book! Email* I'm interested in…* YES, HOOK ME UP! -The story of the fattest man on the island…[12:10] -Why kids like ice cream and not brussels sprouts…[18:50 & 27:00] -How chocolate serves as a prime example of reinforcing properties that characterize modern food addictions…[23:15] -How you can beat the “buffet effect”…[29:00] -The three things all nonindustrial diets have in common, and how you can use these things to keep yourself from overeating…[36:05] -Why the idea of moderation in eating is totally foreign to hunter-gatherers…[48:40] -A simple mechanism you can use to fight your natural, ancestral tendency to overeat…[57:00] -What lesioned rats can tell you about the mysterious “satiety factor”, and how you can maximize your own satiety factor…[64:05] -Why the people from the Biggest Loser gain so much weight back after the competition…[75:10] -A cortisol-like drug that causes intense, unconstrained eating, and what that means for you and your waistline…[84:45] -And much more! Resources from this episode: -THE HUNGRY BRAIN: Outsmarting the Instincts that Make Us Overeat -The book The Jungle Effect –Jack Kruse’s Leptin Reset –My podcast with Rick Rubin Show Sponsors: -Oak – Meditation & Breathing – Go to bengreenfieldfitness.com/oak now to download the app, completely FREE. -Kion Lean – Go to GetKion.com to purchase Kion Lean – an innovative weight management & anti-aging product that regulates blood sugar and insulin levels using bitter melon and rock lotus extracts
Read more at: https://bengreenfieldfitness.com/podcast/fat-loss-podcasts/the-hungry-brain-outsmarting-the-instincts-that-make-us-overeat/