Junk Food Diet Causes Rats' Brain Pleasure Centers To Become Progressively Less Responsive

ScienceDaily, Oct. 27, 2009

Brain pleasure centers became progressively less responsive in rats fed a diet of high-fat, high-calorie food, a new study by the Scripps Research Institute has found.

As the changes occurred, the rats developed compulsive overeating habits and became obese. The overeating continued even when it meant the rats had to endure an unpleasant consequence (a mild foot shock) in order to consume the food.