Can You Be ‘Addicted’ to Food?
It’s not just an empty stomach that drives you to dig into a bag of chips. There’s also your brain, which has a weighty effect on how much you eat.
Scientists know that the brain “rewards” us for activities that benefit our survival, such as eating and reproduction. When we eat to satisfy our hunger, we are rewarded with a pleasurable feeling. But these same rewards can lead to addiction and negative behaviors, such as overeating.
Now, there’s some evidence that overeating and other addictions—such as alcoholism and drug dependence—could be influenced by the same systems in the brain that control these rewards. However, current research reveals how very complex these systems are. And so far, scientists aren’t sure how they work.
Our appetite is controlled, in part, by chemical signals from an area of the brain called the hypothalamus. When our bodies need food, the hypothalamus triggers hunger. When we are full, the digestive tract plays the reverse role—it releases chemicals that actually stop the hunger signals.
But something happens to these signaling systems when we eat foods that are high in fat and sugar. Our hunger signal gets turned on while our “full” signal gets turned off. Plus, our body’s reward system—the one that gives us a pleasurable feeling—gets turned on. This can lead to overeating.
Why would our bodies “reward” us to choose foods high in fat and sugar? Because we can turn these foods into energy quickly. This would have been a plus to our ancient ancestors, scientists say.
Drugs and Food: A Connection?
There’s some evidence that food and drugs turn on the brain’s reward systems in the same way. When a person eats high-fat, high-sugar foods in large quantities and during a long period of time, the brain can undergo the same changes found in people addicted to drugs.
Related brain processes also may explain why people tend to have food cravings, which can contribute to overeating and eating disorders. The most commonly craved foods tend to be high in fat and sugar, such as chocolate, candy, and pizza. One study examined the brain activity of people while they were craving their favorite foods. Researchers found that the foods activated the brain in the same way drugs do.
Delving Deeper Inside the Brain
Doctors have studied a number of brain chemicals connected to overeating and addiction. For example, opioids in the brain might drive our food preferences. They may affect our desire to “go back for more” food and make our feelings of hunger more intense.
Dopamine, too, may be an important player. This naturally occurring chemical can help regulate mood and feelings of pleasure. Research shows that the sight and smell of food can cause the brain to release dopamine. Other research shows that when dopamine activity is reduced in the brain, it can lead to obesity as well as drug addiction. One study found that insulin resistance combined with fewer dopamine receptors than normal could hasten diabetes as well as obesity. The same dopamine problem has been found in people addicted to drugs.
In addition, scientists are looking at the brain chemical serotonin. Levels of serotonin can be affected by drug use. Some experts think that serotonin levels also may trigger cravings for carbohydrates.
Exploring the Controversy
For now, the idea that overeating and addiction are related is still somewhat controversial. Generally, it’s not known whether people can actually develop a “dependence” on food, as they can drugs. It’s also not clear whether removing “addictive” food can create true withdrawal symptoms. Many scientists don’t believe there’s enough evidence to call overeating “food addiction.” But more studies are underway.