The idea that a person can be addicted to food has recently gained increasing support. That comes from brain imaging and other studies of the effects of compulsive overeating on pleasure centers in the brain.
Experiments in animals and humans show that, for some people, the same reward and pleasure centers of the brain that are triggered by addictive drugs like cocaine and heroin are also activated by food, especially highly palatable foods. Highly palatable foods are foods rich in:
Like addictive drugs, highly palatable foods trigger feel-good brain chemicals such as dopamine. Once people experience pleasure associated with increased dopamine transmission in the brain's reward pathway from eating certain foods, they quickly feel the need to eat again.
The reward signals from highly palatable foods may override other signals of fullness and satisfaction. As a result, people keep eating, even when they're not hungry. Compulsive overeating is a type of behavioral addiction meaning that someone can become preoccupied with a behavior (such as eating, or gambling, or shopping) that triggers intense pleasure. People with food addictions lose control over their eating behavior and find themselves spending excessive amounts of time involved with food and overeating, or anticipating the emotional effects of compulsive overeating.
People who show signs of food addiction may also develop a kind of tolerance to food. They eat more and more, only to find that food satisfies them less and less.
Scientists believe that food addiction may play an important role in obesity. But normal-weight people may also struggle with food addiction. Their bodies may simply be genetically programmed to better handle the extra calories they take in. Or they may increase their physical activity to compensate for overeating.
People who are addicted to food will continue to eat despite negative consequences, such as weight gain or damaged relationships. And like people who are addicted to drugs or gambling, people who are addicted to food will have trouble stopping their behavior, even if they want to or have tried many times to cut back.