Is Junk Food Addictive?

In a recent paper in Nature Neuroscience, two researchers at the Scripps Research Institute in Florida report that obese rats with extended access to what they deemed “palatable food” — bacon, sausage, cheesecake, pound cake, frosting and chocolate — exhibited compulsive like eating behavior, much like rats with extended access to cocaine or heroin [1]. This compulsive eating meant that they continued eating despite negative ramifications, in this case a flash of light signaling an oncoming electric shock administered to their foot. This lack of control over behavior with known negative consequences is a hallmark of both drug addiction and obesity. The investigators found that just like drug addicted rats, these obese rats had fewer striatal (a region of the forebrain) dopamine D2 receptors; this is responsible for the observed dampening of their neural reward responses to the food, which caused them to continue to eat, seeking that elusive high.