It’s nighttime, and the cookies are beckoning. Maybe you’re stressed, maybe you’re lonely, maybe your boss, kids or mother-in-law is working on your last nerve. Or maybe you just saw a commercial for chocolate chips and thought, Yeah, a cookie sounds good right about now. So then the bargaining begins. Just one, you think. What’s one cookie? That’s no big deal. What’s not considered: One will probably lead to five, which will lead to another handful, which will lead to emptying the package. By the end, you’re not even tasting the treats. You’re just chewing and swallowing. You eat until every crumb is gone.
If this sounds familiar, you may belong to a subset of overeaters who are addicted to food. While not all obesity experts agree, a steady stream of studies over the past decade suggests that the fatty and sugary offerings so common in the U.S. diet—what researchers call highly palatable foods—hook some people in a way that’s biologically similar to the way cocaine or cigarettes do. “My view is that there’s a population of overweight people who have a problem with highly palatable food the way other people have issues with gambling or crack cocaine,” says Paul Kenny, PhD, associate professor of molecular therapeutics at the Scripps Research Institute in Jupiter, Florida. And like narcotics addiction, food addiction has physical repercussions that help keep you enslaved. “Eating these foods changes your brain in ways that impact your choices,” says Kenny. “Even though you know your eating is unhealthy, your brain is still directing you to these foods.”
Research suggests that 5 to 10 percent of the U.S. population suffers from food addiction; one third to one half of bingers and bulimics are thought to fall into this category. (To see if you meet the definition of a food addict, test yourself with this quiz.) A much bigger group of Americans may be borderline cases, and according to Yale University researcher Ashley Gearhardt, PhD, they have this in common: “It seems that people with some signs of addiction—for instance, they are unable to cut down their food intake when they want to—have different brain patterns in response to food cues than normal eaters.”
Food addiction helps explain why so many people ultimately fail to lose weight on traditional diets. It also implies that help could come from solutions based on brain chemistry rather than food restrictions. “We tend to blame people for not having enough willpower to stick to a diet,” says Gearhardt. “But highly palatable foods are addictive, and white-knuckling your way through is just not going to work.”
Here’s what’s going on in the biology of a food addict—and how an addiction can be overcome.
The Biological Imperative
Kenny has done some of the most persuasive studies demonstrating that in susceptible people, fat and sugar can hook the brain’s reward system. In one pivotal study, he fed rats American favorites like cheesecake, bacon and sausage. The heavier the rats became on this diet, the less they enjoyed their food (as measured by electrodes implanted in their brains). Yet they ate more and more compulsively. This dive in reward-center activity, says Kenny, also happens with rats that compulsively consume cocaine or heroin. As a result of that drop in enjoyment, he argues, both rats and people consume more and more of the cocaine, heroin or food in search of their previous high.
A key to understanding how highly palatable food affects the reward system is dopamine, a neurotransmitter that’s released in the brain whenever we have amazing sex, get high on drugs or enjoy a seriously satisfying snack (especially one with lots of sugar or fat or both). When you do something pleasurable, dopamine is responsible for your urgent desire to do that same thing again.