Overeating Driven By Same Mechanisms As Drug Addiction
A new study from The Scripps Research Institute finds that the biochemical mechanisms responsible for drug addiction are also behind the compulsion to overeat junk food.
The study manipulated the diets of two groups of rats in order to examine their responses to indulging in junk food. One group of rats was given unlimited access to high-calorie foods like bacon, pound cake, candy bars, and other junk food. The rats gained weight and kept eating, even when they knew that continuing to eat would result in an electric shock to their foot.
In contrast, a group of rats few a well-balanced, healthy diet with only limited access to junk food gained little weight and stopped eating upon receiving the cue that a foot shock was coming.
Moreover, when the obese rats' diet of junk food was replaced with healthier food, the rats refused to eat most of it for two weeks.
A look at the obese rats' brains found declines in the dopamine D2 receptor that has previously been linked to cocaine and heroin addiction.
Why Is This Important?
Overweight and obese people, as well as anyone struggling with overeating, often report feeling powerless to change their eating habits. Unfortunately, their plight is often met with little sympathy. This new research shows that overeating, particularly overeating junk food, can lead to changes in the brain that are similar to those found in drug addicts.
Study author Paul Kenny explains that "What we think is happening is that, as you become obese over a period of time, the D2 receptors go down, which plays a major role in becoming a compulsive eater." Other factors are almost certainly involved, but it is clear that compulsive eating has significant similarities to drug addiction.