Researchers at the University of North Carolina reported, in a study published in the journal Science, that stimulating certain cells connecting the amygdala and the hypothalamus of mice could stimulate impulsive overeating- "voracious feeding behavior"- even when the mice were well fed. These particular areas of the brain are a part of what’s called the “limbic system”, responsible for insuring that survival instincts get top priority.
As early as the 1960s neuroscientists electrically stimulated the lateral hypothalamus and saw that it played a key role in feeding behavior, and in the reinforcement of feeding behavior. This current research focused on the hypothalamus as well, one of the brain's most primitive structures, and a crucial part of brain circuitry that drives us to eat and drink, to seek out sexual partners, and generally to crave more of what makes us feel good. The lateral hypothalamus is connected to the amygdala, where basic, powerful emotions like fear, anger and love are processed.
This connection between eating behavior and powerful emotion is consistent with other research suggesting that stress and overwhelming exposure to food triggers overeating. Moreover, the study results may identify a target for intervention in the epidemic of obesity and type 2 diabetes associated with overeating.