Outsmarting the Hungry Brain: An Interview with Stephan Guyenet
The author of The Hungry Brain: Outsmarting the Instincts that Make us Overeat explains how we're betrayed by our very own brains, which lead us to crave and overeat foods that aren't good for us.
Although most of us strive to eat well, our behavior doesn't always live up to our good intentions. Obesity researcher Stephan Guyenet, PhD, explains how our brains are actually wired to undermine our best efforts. In this interview, Dr. Guyenet highlights the unconcious processes that lead to cravings and cause us to overeat and gives his advice for outsmarting the hungry brain.
ND: You write that our neurological and chemical responses to food have evolved over the course of millions of years, during which, for most of that time, food was relatively scarce and hard to come by. Now, we're overwhelmed by cheap and tempting food everywhere we look. Obviously our brains aren't going to be changing any time soon, so how can we overcome this mismatch between our biology and our environment?
SG: The answer is that, though we imagine ourselves as rational beings who are able to exert control over whatever situation comes to us, we're often just responding to the cues in our environment, such as the presence of tempting foods within arms reach. The way to control these impulses is to design your environment in such a way that it guides your behavior in the right direction. For example, limiting your food environment to healthy options, so that you're not forcing yourself to exert willpower because there's something really tempting right in front of you.
One of the major themes of my book is that many of our decisions are made on the basis of impulsive, non-conscious brain activity that we have no control over. These impluses influence our behavior in ways that we can manage, but not necessarily control. For example, take a craving—where does a craving come from? It comes from non-conscious brain activity; it's not something that you choose to bring into your mind. You can manage how your behavior responds to that craving, but you can't get rid of the craving or decide not to have it. So if many of our behaviors are guided by non-conscious brain activity, then how can we possibly do anything about it with the rational parts of our minds that want us to be healthy?
ND: At the end of your book you specifically warn the reader about food reward, the way in which certain foods reward our brains. It almost sounds like you're saying the way to eat less is to make sure we're not enjoying our food too much, which doesn't sound like much fun! Are our brains simply not designed to allow us to enjoy things in moderation?
SG: First of all, I want to be clear that the concept of food reward is just one element that influences food intake. However, it is a factor that greatly affects our intake. The brain has certain properties that it's hardwired to look for in food. When it finds those properties in food, it motivates us to eat the foods that contain them, and the more of those properties that a food contains, the more motivated we become. Generally those properties revolve around things that supply calories, like sugar, fat, starch, and protein.
The brain is very strongly wired to prioritize foods that it finds valuable.
Think about this from the perspective of evolution. For millions of years, our ancestors had to fight to get enough food to survive every day, and calorie intake, in addition to ensuring survival, was also a major determinate of reproductive success— in other words, how many children you're going to leave behind, which is the currency of natural selection. Because of this, our brains are very deeply hardwired to look for calories, and this is a very strong reason why we want to eat certain foods. When you're in the presence of a food that the brain views as highly desirable because of the properties that it has, the brain is going to motivate you to eat more of that food that it considers desirable. The brain even starts to sweep away all the things that would normally limit your intake, like satiety, so you end up being able to eat a lot more calories than you otherwise would.
The brain is very strongly wired to prioritize foods that it finds valuable. I'm not saying that we can't ever eat things that taste good—that's unrealistic. But if we tend to focus on simpler, more satisfying foods, and limit those foods that really cause us to lose control, then it makes it much easier to regulate your calorie intake in a healthy way.