Today on the Doc On The Run Podcast we’re talking about Stress Related Eating and the Consequences for Injured Runners.
Dr. Segler: I’m really excited to have Dr. Stephan Guyenet as a guest expert today. Dr. Guyenet spent 12 years at the University of Washington as a neuroscience and obesity researcher. Much of that time he was studying the role of the brain in eating behavior and body fatness. His publications have been cited more than 1,400 times by other scientists and in peer-reviewed scientific publications. He is the author an intriguing book entitled “The Hungry Brain” which explores the neuroscience of overeating, focusing on the following perplexing question: Why do we overeat, even though we don’t want to?
One of the reasons I wanted to have him on the show is that I have noticed many injured runners and triathletes let their diets slide a little bit when they get hurt. When we talk about this it quickly becomes apparent that these athletes understand nutrition. They understand the value of quality ingredients going into their system. They know what they need to eat to recover from hard workouts.
They also recognize oftentimes that an overtraining injury is nothing more than the sort of tissue damage that happens in regular training. It’s just that the damage went a little too far.
Because the same process of tissue repair has to happen to heal that overtraining injury you would think that nutrition, getting those necessary ingredients into the body, would be at the forefront of their thoughts and actions.
But then I hear all sorts of weird justifications from runners. I hear them say “Well I’m not really training right now. “ or “I’m not working out right now so what’s the difference”. The difference of course is you’re not going heal unless you prime your body to do so.
So in this episode Dr. Guyenet is going to help us understand the psychology associated with the way we eat and he is going to help us understand why we let our nutritional disciplines slide and what we can do about it.
Dr. Guyenet: Thanks, it’s good to be here.
Dr. Segler: All right! So before we get started in all this why don’t you just give us a little bit of background about your training, your research and why you became so interested in the neuroscience associated with eating habits.
Dr. Guyenet: Yes, I have always been interested in neuroscience and I have also always been interested in fitness and a nutrition just for my own personal fitness and well-being perspective and I got my PhD at the University Washington studying Neurodegenerative Disease and at that time I knew I wanted to study neuroscience but I didn’t know what part of neuroscience I wanted to study and I was working on a relatively very rare disease called SCA7. I won’t a tell you what that stands for, it’s a tongue twister and eventually I just kind of decided that I wanted to do something that was more impactful of more people.
I figured what better way to bring together my interest in nutrition and fitness and my interest in the brain than to study the neuroscience of eating behavior and obesity. And so that’s what I did for my post-doctotrate with Michael W. Schwartz at the University of Washington.
I had this really simple, very very fundamental insight about eating behavior and body fatness and its relationship to the brain and by the way I didn’t think of this. I wasn’t the first person to think of this. But it was still, it’s still I think a very powerful idea that a lot of people haven’t fully internalized and that is simply that the brain is the organ that generates all behavior. It’s the organ that generates all behavior, all feelings, all impulses, all cravings, all of that.
If you’re trying to understand eating behavior and the things that eating behavior affects such as your body fatness, your health, your ability to recover from injury, understanding the he brain is really a very logical frame to take when trying to do that. So I realized very quickly that we were studying the right word and to understand this problem.
I guess over the course of doing that research and learning more about it both through the research that I was doing personally and learning about other people’s research in that field, I kind of came to the understanding that here’s a lot of really important research that’s being done right now that has been done that gives us profound insights into how the brain determines our behavior and what we can do about it. But that information was not really getting to the public in a very coherent way. So people had all kinds of crazy ideas about what determines eating behavior, what determines body fatness or they just had no idea.
I ended up trying to fill that information void with my book “The Hungry Brain” which is an attempt to take a lot of that research put in together in a coherent form that’s understandable for a general audience. So that’s what brought me to this present moment.
Dr. Segler: Yes, that’s interesting and I think it’s true it is worth pointing out that the brain is in-charge of everything we do. Although we think about it a little bit differently sometimes and it’s interesting to me that sometimes people think of depression as a state of feeling. But they don’t necessarily attribute to the brain even though all the medications are given for depression obviously are affecting the function of the brain.
I was just talking about earlier in this pattern with inured runners that sometimes doctors of course tell runners to stop running and then sometimes they stop exercising and hey get a little bit depressed and maybe even get some mild depression. And I see runners all the time they’re eating what we call comfort foods and the foods that are not going to facilitate healing and although I know that’s not specifically your area.
I’m just kind of interested in your perspective as a neuroscientist and it’s obvious, somebody’s an expert on eating patterns. What is it that takes these people who are these well-informed, highly competitive, highly-educated athletes to start eating foods that are not in alignment with their overall goal of healing and recovering? What is it that you can tells about those non-conscious brain circuits that really do drive us to overeat in general?
Dr. Guyenet: Yes this is a really interesting question and it brings us back to this broader question which is why would we do anything that we don’t want to do. The risk of obesity in the United States right now is greater than fifty percent. So more than one of two people will develop obesity at some point in their lives in the United States right now. These people do not want to develop obesity. Pretty much no one wants to develop obesity. They don’t want to get heart attacks. They don’t want to get the diabetes. They don’t want to get arthritis. They don’t want to get a higher cancer risk. They don’t want to get all these things that are really really bad outcomes that you have a higher risk of when you’re in that state.
But we do it anyway and we do it consistently through our behaviors every day and I say we. Probably a lot of people listening to this right now are not in that camp. At least not as much as the average person. But the fact remains that there are a lot of things that we do where we engage in behaviors that our better judgment tells us not to engage in and so clearly there’s some kind of conflicting goals happening in different parts of the brain. You have your rational conscious reflective regions of your brain that are saying I want to look good in the bathing suit next summer, I want to be in peak physical performance to win this race next week, I want to have a low risk of cardiovascular disease. I want to be able play with my kids when I’m seventy, play with my grandkids. Then you have another part of your brain that says I want to eat this chocolate cake right now. I want to stuff this doughnut in my face. I would rather sit on the couch.
Essentially we have these signals that are coming from different parts of the brain that are generated by specific brain circuits that have specific functions that actually made a lot of sense and the context of our ancestors. So the human brain evolved over about five hundred million years. Of course it wasn’t the human brain at the beginning but to support our survival and reproduction needs and these circuits, the things that make us crave, the things that give us an appetite, sometimes too much of an appetite, the things that determine how much food it takes for us to feel full at a meal. These are brain circuits that are involved in a specific evolutionary context in which they were supporting our survival and reproduction.
But once those things are thrust into an environment where that’s very different in the one we are involved in, they are essentially misfiring because we like to view ourselves as these kind of conscious rational beings that are in complete control of our brain activity and behavior. But the truth is that most of your brain activity is beyond your conscious awareness.
So just consider this, when you experience a craving, when you smell a chocolate chip cookie or a slice of pizza, where you see a piece of fried chicken or something like that, really unhealthy, really tasty and you crave it. Where did that craving come from? You don’t decide that you want to experience a craving and you don’t decide that you wanted to push your behavior in the direction of eating that food. But that’s something that arises from non-conscious brain regions that are processing sensory stimulating in your environment and pushing you toward that outcome.
That’s the kind of general framework that I’m trying to lay out here and I’m speaking in generalities right now. But in fact we know a lot about the specific brain regions that are causing these different impulses to occur and they can be very very persuasive. And that has major impact on our lives in terms of what foods we select, how much we choose to eat, how easy it is to lose weight, how easy it is to maintain weight.
One of the things that you mentioned was people who eat comfort foods so in fact there’s also a neurobiological basis for that. If you look at surveys by the American Psychological Association. They show that about I believe Forty-three percent of people overeat when they experience stress in their lives and they report overeating and then about thirty-five percent report skipping meals. So it’s very individual how people respond to stress but a large number of people do overeat when they experience stress.
For example if you’ve been injured, you might be in a stress state of physically and psychologically and that does a couple of things. One of the things that does is it increases the secretion of this hormone called cortisol. Cortisol is a steroid hormone that acts on a number of parts of your body but one of the things it does is it actually impacts the brain circuits that regulate your appetite and body fat as it binds to receptors in those brain regions and causes you to eat more calories of food and causes your body to tend to want to pick up more body fat.
But the other thing that happens is that whether we actually overeat or not, we tend to gravitate toward these calorie dense comfort foods and there’s also a neuroscientific basis for that. And the reason is that if you look at these brain circuits that generate the stress response because again the stress that you feel is generated by the brain. Everything that you feel generated by the brain. If you look at these stress responses, they’re actually dampened by highly palatable calorie dense food and not just food that does it. You can also do with sex. You can probably do with anything else that is pleasurable.
Dr. Segler: Yes, alcohol like I would imagine like narcotics. All those things right? They’re somewhat related. It’s in the same area in the brain that is causing these sort of pleasurable responses in response to whatever it is covering up the stress?
Dr. Guyenet: Similar, yes and they haven’t tested all the different things that can help dampen the stress response but there’s actually a really well-established neuroscientific basis for that idea. And the upshot is that different types of pleasurable satisfying things in your life can kind of substitute for one another. So you might feel like sitting on the couch and eating ice cream but you might feel just as good by taking a hot bath or taking a walk or calling a friend or doing some gardening or something like that.
Dr. Segler: That’s interesting. So that makes sense to me but it’s interesting because we all know that, well athletes in particular know that for example that exercise makes them feel good. They have been on this long course of training and getting stronger and getting faster and so on and there’s only one way to get there. It’s through difficulty, through hardships. Runners, triathletes, they all pick this sort of hardship and difficulty, adversity, hard efforts and execution of those no matter what when they’re training. They go do speed work. They run in the rain, do hill repeats, they go to the gym, lift weights, sit in ice bath. All these things are uncomfortable and they do all these physically unpleasant things without any hesitation because they know it’s going to pay off. They know they’re going to get stronger and they have a confidence that they’ll get faster if they continue to pick this hard road and just stick with it.
So I’m interested from a neuroscience perspective in discussing this idea that you just presented to as like what is it like what can athletes do I mean because if they can’t run, they can’t exercise, if their doctors told them they have to stop all the exercises so they can heal some injury mean. Maybe the idea of taking a hot bath would do it. If there’s something to substitute but what is the approach like from what you know about this sort of neuroscience perspective on it and the neurobiology of it. What is it that athletes should understand about their responses to stress that they can use to sort of work around that? Because many of them really do develop to just thinking “Well all I can do is sit on the couch and eat some ice cream” and obviously there’s something in control of those cravings. If there’s a way, what’s the work around?
Dr. Guyenet: You mean the work around for reducing the experience of stress?
Dr. Segler: Well they may not be able to do that and that’s part of my approach is I’ll try to figure out ways, in very individualize ways for athletes to stay active, to burn off the stress and to do some sort of activity to provide them with the normal release that they get through activity. But that’s unusual, most doctors will tell athletes to stop exercising the argument being that they need to rest and recover and if they’re exercising and doing the additional tissue damage. Then it’s just less energy to heal the stress fracture or the tendon tear.
I mean in work around, what sort of strategies in terms of these cravings that we know contribute to body fatness which also makes most athletes feel worse when they realize they perceive themselves to getting, they’re getting pudgy, they’re losing their strength of losing their fitness and they’re getting body fat that they really don’t want to carry during their next race. What is the work around in terms of identifying that these things do relieve stress if they take a hot bath or call friends? What did most normal people who don’t really have this outlet of athleticism to reduce their stress?
Dr. Guyenet: Yes so I think there are a number of things you can do to control your eating behavior and a healthier direction and if you’re in that situation. Athletes are in a situation where most athletes are engaging in a high level of physical activity and that’s something that is going to help oppose fat gain. So that’s something that’s generally going to help you be leaner and so you might not have to worry as much about your diet being fattening if you’re engaging in a high level of physical activity on a regular basis. But when that goes away then you need to start focusing on your diet more if you don’t want to start gaining weight. That is if you’re someone who is susceptible to waking. But most of us are.
Dr. Segler: Based on what’s going on with the risk of obesity right?
Dr. Guyenet: Yes well it’s more than that because that’s a lifetime risk of obesity. But if you add overweight to it, it’s more like seventy percent.
Dr. Segler: Oh wow.
Dr. Guyenet: Yes, so there’s not really that many people in this country who will be lean for their entire lives. Although I’m sure that those people are over represented probably listening to this podcast. Basically if you take away one thing that’s controlling your body fat and if you need to up your game in other areas and diet is obviously a way that’s going to be helpful for that. So I just explained one way to try to control stress eating which is to replace stress eating with other types of stress relieving behaviors that are more constructive. Calling your friend, taking a bath, having sex, things like that.
But you I’ll be honest, there’s not a lot of things that can really compete effectively with delicious food. So the problem is its yes I could go outside and garden but I can get a lot of pleasure just from sitting here and eating this ice cream for basically no effort right?
It’s hard, it’s hard to compete with that and the brain knows it. You are going to be better off if you apply some other strategies too and I think one of the most just a really simple but very effective strategy for guiding your eating behavior in the right direction and by the way my whole strategy, my whole outlook depends on this idea that we’re not really, it’s not a commanding control exert willpower type of scenario. Like you will have to exert some willpower. There is some effort involved in controlling your eating behavior but the goal is not to say “Okay I am going to count exactly a number of calories I need and I am going to sit in front of this table of pizza and ice cream and only eat the number of calories that are appropriate for maintaining my weight. That you’re setting yourself up for failure if you are surrounding yourself for temptation right and that’s not to say that no one could ever succeed in that situation. But it’s just going to be a lot more difficult and most people are going to fail.
So what you want to do. Is you want to and by the way the reason you’re going to fail is because of those non-conscious brain regions that are creating those temptations, creating that hunger and pushing you toward eating those foods. If we only had a rational conscious brain, we could stop whenever we wanted and it wouldn’t be a problem. We could easily say no to the cookies and the pizza and all that stuff that’s not the brains that we have. So what you have to do is you have to feed those non-conscious circuits the right queues that guy them in the right direction so that they are supporting your goals instead of undermining your goals.
One of the things we know is that these circuits that drive your eating motivation, that drive your craving, they’re very responsive to the queues in your environment. Sensory cues. Things like smell, things like to site the food. So when you see a piece of pizza or cookie or you smell it or you’re in a place where you’re accustomed to eating in or your with people or in a situation where you’re accustomed to it. Like let’s say you’re watching a football game and there’s always chips and dip. When you watch the football game. When you’re in that situation, you’re going to want chips and dip and you’re probably going to find a way to make it happen unless you’re being really careful with yourself.
Controlling the sensory queues in your environment and say “Wait a minute, I know that when there are cookies visible on the table, I’m likely to eat them”. I know that when I can smell a fresh big loaf of white bread, I am likely to eat and put some butter on it and overeat. Just remove those things from your surroundings. Don’t expose yourself. The food queues in your daily life.
My strategy and I think this is what most people benefit from it is to not have any visible food at all in your kitchen or in your workplace or anywhere in your house or in your workplace. Except for a couple of strategic items that you would only eat if you’re actually hungry. Things like oranges that you have to peel to get inside, you’re creating a small effort barrier for yourself.
Things that aren’t that palatable like unsalted nuts, raw nuts maybe or peanuts should be roasted of course. Those are things that taste okay. They just pretty good I mean you will eat it if you’re hungry but if you’re not hungry, you’re not going to peel an orange and eat it. If you’re not hungry you’re not going to unsalted peanuts and eat them. So they’re available for you if you need a snack but they’re not calling to you like cookies or chips or soda or and I’m giving the worst examples cookies and chips and soda. But I mean you could even have things that are relatively healthy but are just very tempting. Things that are really delicious and you could still overeat those and ultimately whether it’s healthy or not healthy, if you eat too much of it you’re going be gaining weight and so I think a really important strategy is controlling your food environment to control those queues that you’re presenting to the parts of your brain that are setting your intrinsic impulsive motivation to consume food.
Dr. Segler: Rgiht. It’s interesting something you just mentioned because I like cashews and I normally buy these ones that are actually roasted that are like lower salt version. I perceive them to be healthier than the ones that I really like which are of course the completely coated with salt to the point that they look like they’re glazed. But I recently went to buy these and I used to always do the raw unsalted, unroasted version and I’ve got those by mistake. And so today I was actually driving in my car and I was really hungry. I didn’t have time to stop and so I did eat some of those but I did notice that I basically ate as much as I needed to eat to not really feel like I am starving but then put I them away.
You just mentioned the salted snacks and having unsalted peanuts instead of those are salted and so I know that salt, sugar, fat, they are all relatively rare as naturally occurring substances in nature? Like many years ago somebody hunting and gathering is pretty difficult to get those things. But it’s pretty easy now. You go to the grocery store, you can buy stuff labeled with salt, sugar and fat and so what sort of impact does that have if it’s salted because we always think of sugar and fat like ice cream. But what sort of impact does salt have on driving that overeating behavior in a way that’s not so beneficial for us?
Dr. Guyenet: Yes so essentially the brain has certain things that it’s looking for in food. Certain things that is hardwired to seek and that it’s intrinsically motivated to seek and so those include fat, includes carbohydrate, it includes protein and then include salt and those are really the main fundamental basic food properties the brain is looking for.
If you go to a fine dining restaurant you might have some aesthetic appreciation for the presentation or the aroma but the thing that’s really going to get your cravings going is those really basic concentrated nutrients, the sugar, the white flour, the added fat, the butter. That sort of thing is what in the salt is what’s really going to get your motivation going.
Basically the brain sees those food property is as valuable and it wants you to eat those things that would have supported the survival and reproduction of our ancestors. It sets your motivation according to the concentration of those things that are found in the food that we are eating.
There are limits, by the way you like you’re not going to shovel big mouthfuls of pure salt but within a certain range, more salt is going to taste better and since the brain likes you to eat things that it’s intrinsically motivated for, that’s going to increase your eating drive. So that’s just kind of explaining why salt increases eating drives and it does. I mean I can tell you for me when I’m eating pistachios, the salted ones, I mean I might as well put those in a crack pipe and smoke because they are incredibly addicted to me. I mean my wife and I just went through a big bag of those and just days.
I tried to personally eat right avoid salt on nuts especially roasted nuts because that to me I will overeat those and I know a lot other people will and nuts are relatively calorie dense. When you present to the brain a food that it considers to be intrinsically very valuable, it will increase your eating drive toward that food and it will often cause you to over consume it relative to what actually is good for you. Where is if you have a food that the brain kind of shrugged its shoulders about, something really plain, something that is nutritious, a protein that really sets the brain on fire.
The intake of those is really going to be more controlled not by those pleasure circuits and not motivational drive circuits but by the circuits that regulate your body’s energy status. So basically the circuits that are just trying to replenish your energy and get you back up the baseline. Not the circuits that are going to push you beyond that.
Dr. Segler: Right, I mean it’s true. I have more than once eaten so much pizza that I just felt like “Oh my gosh , why did I do that?” I have never ever had that sensation eating carrots, it just doesn’t happen. So it’s true, the foods that are low of fat and sugar for whatever reason I’m driven to eat way more than I need and it doesn’t make sense, it just doesn’t. But again it’s the same thing you’re talking about.
Actually I remember telling a patient just recently said “Your brains can outsmart you every time” and that sort of way it sounds silly but it’s true. Our brain is really in charge what’s happening. Even though we want to believe that are conscious brain. The things that are making decisions about are actually controlling our behavior. It’s not true. It is only a very small proportion of our brain power is our conscious thought and I think that runners being disciplined kind of overlooked that.
I think, really close to a hundred percent of all successful athletes think they’re in control what’s going on and that’s not always true. Sometimes I wonder about when they get injured and they start to lose their sort of positive mental outlooks. They get a little bombed down, a little depressed and they feel like they’re losing control. How much that contributes to this sort of overeating behavior or less than positive behavior let’s say? I know this isn’t really your area but I don’t know if you can speak to this at all. But what about eating calorie dense foods that are high in sugar, salt and fat? Is there much evidence that really does affect our capacity to maintain a positive mental outlook? Because it seems like there’s a lot of association between that and over your behavior.
Dr. Guyenet: It’s a good question and it’s really not something I know much about. But I’ll just say in a very general sense that your brain is an organ in your body and it’s supported by all of the other physiological processes that are happening in your body. If you’re not eating and doing the things that are supporting your overall physiology, you’re not eating and doing the things that are supporting your brain function either and that’s going to manifest in many way possibly including your mood state, your mental health, your pure focus, your motivation level etc.
Dr. Segler: I guess part of it is just that you can get so strong and so fast in pretty much any athletic field with just a lot of discipline and I personally believe talent is overrated and I think that discipline is way more important when it comes to running. Particularly endurance sports like marathon, running Ironman triathlon, all that kind of stuff, Ultramarathon. I think that discipline is extremely important because it’s just take so much effort and I know that discipline alone is not enough to get somebody an Olympic gold medal. It certainly can get you to what most people perceived to be a high level of physical fitness and that maybe requires talent. But it’s not really talent, its just discipline.
I think it confuses injured athletes because they perceive themselves as being very disciplined and then they don’t really understand necessary while they’re eating the wrong food sometimes and I remember watching documentary on there was this chronicle on a bunch of professional Ironman triathletes and one of them in that documentary is Peter Reid who won the Ironman World championships more than once and one of his training partner showed up at his home in Arizona where he does training. But he basically would rent this house and just go and train all the time for a few months. More or less an isolation and he opened the refrigerator and there were like two or three things, literally two or three things in the refrigerator and he said “Peter you don’t have any food in here” and he said “I know, if I have any food then they are all cheat”.
It was fascinating because you think the guy’s a World champion. He must just be able to have discipline that you can completely control everything. But that’s part of it is he was clear enough to know that he actually was not so discipline that he could fight this poor impulse control that rises when we have these highly addicted foods.
Aside from the recommendations you made earlier like what is it that athletes can understand that they really have to know about their limitations on discipline and these foods. What part of our brain is that that’s in control when we are forced with these choices in these highly addictive foods?
Dr. Guyenet: Yes, basically willpower and discipline do matter for everything. It’s one of the things that goes into the pot in terms of what determines your outcomes and if you don’t have any discipline, you don’t have any will power, then you’re sunk. You’re hopeless whether you’re trying to control your food intake or be an athlete or be successful at anything else. But that said, our ability to exert willpower and our ability to be disciplined is limited. It’s limited in everyone and furthermore the capacity to do that to desert that varies between individuals. So not everyone has a will of steel to be able to say no to drinking beer when they go over their friend’s house because they’re on a strict training regimen.
Different people have different levels of ability to exert that kind of control and so I think the question to ask is first of all you have to recognize that we’re not infallible. We’re not made of steel, nobody is. We all have a limitations. So the question to ask is how do you manage those limitations most effectively? How do you get the best results with the least effort and the least likelihood of failure? And basically what I’ve come around to is the idea that you want to actually try to minimize the amount of willpower you have to exert.
There will always be some willpower but you want to do was the best you can to minimize the amount you have to exert in the moment when you’re going to be weak and that involves some discipline in advance to set up the situations to support yourself in the future. The food environment I think is a great example of that. You have to have enough discipline to say “No, I don’t want these items on my kitchen counter anymore. I don’t want ice cream in the freezer anymore because my brain knows it’s there and it’s going to start making me want it after dinner”. You have to have some amount of discipline to do that. But it’s a lot less discipline than is required to say no to those things every day when they’re under your nose and you’re feeling hungry and tempted. That requires much more discipline than just getting rid of those things in advance.
That’s kind of the idea is acknowledge the fact that you’re not invincible. That you have brain regions that are trying to undermine you actively and they’re very persuasive and just try to find ways to work with them. Instead of seeing it as a failure or an aberration. Just see it as a weird evolutionary holdover that you have to manage.
Dr. Segler: Right, I mean it’s true. It is eliminating those temptations is it sounds like a simple thing and a few years ago I was trying to qualify for Ironman Hawaii and so I was training really hard. I was very very disciplined about my food, everything, sleep, all of it. I was in Hawaii and my son at that time I think he was in first grade or something and maybe was he in kindergarten. But he was really young and we’re in Hawaii and I sort of in passing when we’re in Hawaii, I was eating this macadamia ice cream with him and said “You know what this is?” and he said “What?” and I said “This is the last ice cream I’m going to have until I finish Ironman Texas” and because I would eat tons of ice cream like after a six-hour bike rider or four-hour run or something like that. I mean I could do it and still not gain any weight but it was not helpful to the process of training that I was in.
It’s not like I would actually gain weight or something but I knew it was detrimental to my overall goals. So I just wouldn’t have it in the house during those periods and I didn’t really think that much about it. But when I went and did Ironman Texas and I’d completely forgotten, it’s been like six months and I went to get my son from school. I’m walking from home and he walked out the door and he ran up and said “Did you do Ironman Texas?” and I said “Yes I did. I just got home last night” and he said “Can we go to Baskin Robbins today?” for it was sort of I mean it wasn’t a great thing because I realized this really isn’t teaching him the best lesson either that the only way to succeed is to deprive yourself for six months or something which I don’t know if that’s ideal. But it is true. If I don’t have ice cream in the house, well there is no concern that if I have some sort of craving for ice cream at eight or nine o’clock at night. There is precisely zero chance I’m going to get in the car and go get some. If it’s in the refrigerator, this is a different issue and it’s very difficult to control it and it is so much of I think it’s driven by these things we are not in control of.
I was actually talking with a guy one time and he was telling me, we’re talking about Ben & Jerry’s ice cream and he said “Some days when I’m really stressed, I just have those days and I’ll take the thing out of the freezer and I just throw the lid on the trash on the way to my couch and he’s like whom I kidding”. The entire thing in one sitting but nobody would think that’s a good choice. It is very difficult so that does make sense to try to just remove those temptations. But as you say this is no pun intended, this is a growing problem and obesity is really an epidemic. When I was a kid, there was literally one fat kid in my elementary school, that’s it and now when I go pick up my son at school. I look at the kids on the playground, it seems like overweight children, it’s the norm, not even unusual. So maybe just tell us a little bit about the sort of diet history of the United States and what you think it is that’s contributing to all this sort of weight gain today that just is so different than what I remember when I was a kid.
Dr. Guyenet: Yes well your memory is not failing you. The prevalence of obesity today is much higher than it was in the nineteen-eighties and nineteen-seventies and actually it was quite a bit higher even in the nineteen-seventies thanit was at the end of the eighteen-hundreds. So there’s been this long progress of increasing body fatness in the United States but it has the rate of gain increased in the nineteen-eighties and nineteen-nineties and actually still to this day and that’s what we call the obesity epidemic.
So something did increase the rate of gain around that time but basically I mean what you have is a gradual but profound change in the way we interact with food in this country. Not just food, I mean our physical activity has declined over the last hundred fifty years. People used to work with their hands. They were working in farms, they were working in factories, there were no washing machines. People were doing a lot of things that their hands that we have now mechanized, we’ve outsourced to machines in our lives. Transportation for example, people used to walk or ride horses and then our diets have changed profoundly. So our food environment has changed quite a lot.
Food is everywhere now. You go into a hardware store and there’s a whole like candy rack by the checkout and it’s that’s crazy and our houses are filled with food because food is so incredibly cheap now that there’s basically no reason not to buy as much as possible of whatever you want. And so we have these like counters overflowing with food and all this abundance of food is stimulating these brain regions that promote excess calorie intake and the food that we’re eating has changed over time. We used to eat simpler home cooked food. So in the late eighteen-hundreds, almost all of the food that we ate was food that was cooked in the home from single ingredients. Today most of the food that Americans at least eat has been commercially prepared in some way or another whether it’s in a restaurant or whether you’re buying something pre-made in the restaurant.
Most of our food expenditures are on food that is already prepared for. So we have outsourced food preparation to people who don’t necessarily have the same goals that we have and don’t necessarily care as much about our body fatness and our health as we do.
The composition of our food has change too. We’re using more sugar, we’re using more added fats, we’re using more of all kinds of flavors and this is really the culmination of the historical process that goes back thousands of years. Essentially there are certain substances and I was referring to them some earlier the carbohydrates, the fat, the salt and the protein that stimulate the release in the brain and those are the things that the brain is intrinsically looking for from food. And we have over the course of historical time figured out ways to concentrate those active ingredients that’s bicarb dopamine. This is kind of an extreme example but it’s a very good analogy is how we took the cocoa leaf which is mild stimulant that is used by people in South America kind of like drinking a cup of coffee, they chew on these leaves and we purified the active ingredient that spikes dopamine out of that which is cocaine, that’s an addictive drug. Then we perform another chemical process which turns it into crack which makes it across our cell membranes more easily and makes it even more addictive.
So essentially we found ways due to the progress of technology. Found increasingly effective ways of purifying, activating these ingredients that spike our dopamine cravings and motivation. We’ve done that with drugs, we’ve done it with food too. So now we have crystal in monosodium glutamate. We have crystal in salt. We have crystal in sugar. Those things are absolute most purified dopamine spiking food substances that you could possibly get. They are a hundred percent pure. We have isolated fat which is almost completely pure. We have starch like cornstarch which is pretty much pure. So we have basically taken all of these ingredients which stripped out everything that doesn’t spike dopamine and then we have put them all together and mixed them together into these things that are really just too irresistible to the brain.
We have done that as our technology has progressed and as our affluence has progressed. We have increasingly been able to apply those processes that make more and more seductive foods. And so this is a process, it’s been going on for a long time and gradually fattening us. But there’s another factor that I think goes at least some of the way toward explaining why we’ve been gaining weight so fast in recent decades and this one might surprise you is the fact that we’re smoking less.
Dr. Segler: Oh interesting.
Dr. Guyenet: Yes, so cigarette smoking nicotine suppresses appetite and body fatness. It is a very well established effect and most people used to smoke. If you go back to the sixties and seventies, most people smoke cigarettes. Today, not that many people smoke cigarettes anymore. The per capital consumption of cigarettes has gone down by about three-quarters since that time and it actually the decline of cigarette smoking lines up really well with the rapid increase in obesity prevalence. That’s not to say that explains all of it but I think it is a factor.
Dr. Segler: In kids, it doesn’t explain it, you think just that concentrated, highly processed, more available stimulants basically I guess we can call it in foods that really affects kids you think?
Dr. Guyenet: Yes, it’s that. Its changes in the food environment. Its changes in the physical activity environment. I think all of those things have contributed.
Dr. Segler: Okay great, that’s helpful. Now in one of the things in your book “The Hungry brain” you talked about which is just out for about a year now right? You talked about the neuroscience of all the body fatness and the ways that our brain undermines our weight goal and you talked about some insights and practical guidelines for eating and the interesting subtitle of your book of courses is outsmarting the instincts that make us overeat. So that’s part of what I really want to talk to is because of runners, we all know how to outsmart our tendency to quit and we have been told over and over and over about discipline and our coaches teach us how to stay on pace for that last mile of training runs. And it seems like your book could also help athletes necessarily because it’s not all about discipline. We don’t really think of this very much because athletes don’t generally consider themselves to be overeater and most athletes are not overweight. Even when we think of being overweight that maybe ten percent body fat or twelve percent body fat.
It’s still not really not overweight by American standards. But we know what is not right for us at racing weight or in our optimal physical condition as an athlete. So what can you tell our listeners about your book and how it can help them better understand the eating patterns that may be impeding their recovery and sort of undermining their efforts? Not just when they’re injured but also in terms of repairing themselves after hard workouts and races as well. How could your book help athletes better understand this whole thing?
Dr. Guyenet: Yes so essentially my book is a tour of the different non-conscious brain regions and things that those regions respond to that cause us to overeat. It’s basically trying to help people understand where these things are coming from that are causing our behavior to betray our best intentions for our eating behavior, for supporting our training or whatever your goal is. What I want people to take away from the book, I want them to understand where this is coming from. I want them to understand where it’s coming from, why it evolved and I want them to be able to recognize it when it’s happening and say “Oh, I have a tool for this. I understand this, I recognize it and I have a tool to manage it”.
As part of my book, I try to explain what we can do to provide the right signals to those non-conscious brain region so that they are supporting our goals rather than undermining them. These brain regions are very responsive to the signals that are coming in from our surroundings, from outside our body and also from inside our body. They’re very reactive to those things and if you can control the stimuli, you can greatly influence those brain regions.
Just to give me an example, I’m speaking in very theoretical terms but to give you a concrete example, there’s a part of your brain called the brainstem and specifically a part of that called the nucleus tractus solitarius that is responsible for determining your satiety or your fullness. And so basically as you’re eating a meal, food goes down into your stomach, it stretches your stomach and signals go up to your and NTS then that food starts getting released into your small intestine which has receptors for all kinds of things. But for example a carbohydrate fat protein and those signals also go up to your NTS and they get integrated into the single satiety that then gets broadcasted to the rest of your brain and says “Hey it is time to stop eating” and so that will cause you the food doesn’t taste as good all of sudden, you don’t really feel motivated to keep putting the fork to the plate to bring it to your mouth. That’s the kind of thing that happens when your NTS reaches a point where it thinks you’ve had enough.
The key thing to understand is that the point at which your NTS decides that you’ve had enough can vary greatly depending on the number of calories at which it gets to that point can very greatly depending on what you ate. Some things are a lot more filling than others because of how brain communication happens and so foods that are higher in protein, foods to have a lower calorie density, fewer calories per wait or per volume, foods that are not as palatable, so foods that just aren’t quite as seductive. Those are things that are actually going to fill you up more per unit calorie and so since we use that feeling of fullness or satiety as a gauge to understand when to stop eating, most people just eat to that and that’s when they stop. If the point at which we get there allows us to eat fewer calories then we’re going to be eating fewer calories at every meal and that’s going to help support our body weight goals. So that’s just a concrete example of how we can provide the right signals to the non-conscious brain to help support our conscious goals.
Dr. Segler: That’s great and I think it’s that this has all been very helpful and I think that your book would certainly be useful for most of our listeners and we will make sure that your book link is on in the show notes as well as all your other of links to your website and all that as well. I think it’s just been great time. I really truly learned a lot from you today and it’s really been great having you on the show and I really appreciate you taking the time out of your schedule to share all of your experience and your knowledge with our listeners today.
What’s the best way for people to reach? If they need help optimizing nutrition, trying to figure out ways to work around these and modify these eating patterns. What’s the best way for people to get a hold of you?
Dr. Guyenet: Yes, so I think my book is really the best distillation of some of my main ideas that I have. But I also have age website where I have a blog and that’s http://www.stephanguyenet.com/. You can also get there if spelling my name is too daunting, you can get there through http://wholehealthsource.blogspot.com/. I also, I’m on Twitter pretty active on Twitter. Mostly I just tweet papers out, it’s pretty heavy science oriented if that’s what you’re into. Maybe you’d find that useful.
Dr. Segler: Okay great! We will put all those links on the website under the show notes as well and make sure that those are accessible as well. Again, thanks for coming on the show! I really appreciate having you here and it’s really been a pleasure.
Dr. Guyenet: All right thank you.
If you have a question that you would like answered as a future addition of the Doc On The Run Podcast, send it to me PodcastQuestion@docontherun.com. And then make sure you join me for the next edition of the Doc On The Run Podcast!
Dr. Christopher Segler is a podiatrist and ankle surgeon who has won an award for his research on diagnosing subtle fractures involving the ankle that are often initially thought to be only ankle sprains. He believes that it is important to see the very best ankle sprain doctor in San Francisco that you can find. Fortunately, San Francisco has many of the best ankle sprain specialists in the United States practicing right here in the Bay Area. He offers house calls for those with ankle injuries who have a tough time getting to a podiatry office. You can reach him directly at (415) 308-0833.
But if you are still confused and think you need the help of an expert, a “Virtual Doctor Visit” is the solution. He has been “meeting” with runners all over the world and providing just that sort of clarity through online consultations for years. He can discuss your injury, get the answers you need and explain what you REALLY need to do to keep running and heal as fast as possible.
You can arrange a Virtual Doctor Visit with a true expert on running injuries. Right from the comfort of your own home you can meet online with the doctor, discuss your running history, talk about your running injury and figure out a customized recovery plan that will help you heal the running injury so you can get back to running as quickly as possible.
Book your Virtual Doctor Visit with Doc On The Run now!