The Overeating 'Addiction'

Obese people's desire to eat triggers the same brain action as addicts' desire for drugs, say researchers at Brookhaven National Laboratory.

The finding is based on seven morbidly obese people treated for up to two years with a gastric stimulator.

The implanted device makes the stomach expand by giving tiny electric jolts to the vagus nerve. This, say Gene-Jack Wang, M.D., and colleagues, signals the brain to make a person feel less hungry.

The seven study participants lost an average 11.6 percent of their original body weight. At the time of the study, six of the seven still weighed at least 5 percent less than they used to.

When the device is turned on, Wang and colleagues now report, it stimulates a part of the brain linked to emotional eating — that is, eating to soothe emotional distress. The participants reported less desire for emotional eating when the device was turned on.

"The brain regions activated by gastric stimulation overlap with those reported during craving responses in addicted subjects, supporting the commonalities in the [brain circuits] that underlie compulsive food intake and compulsive drug intake," Wang and colleagues conclude.

The findings appear in the Oct. 17 issue of the Proceedings of the National Academy of Sciences.

SOURCES: Wang, G.-J. Proceedings of the National Academy of Sciences, Oct. 17, 2006; early edition published online Oct. 2, 2006. News release, Brookhaven National Laboratory.

By Daniel DeNoon
Reviewed by Louise Chang, M.D