Reward circuit function in high BMI individuals with compulsive overeating: similarities with addiction.

CONTEXT: The rising rate of overweight and obese individuals among developing countries despite focused efforts on prevention and treatment underscores not only the need to better define the physiological factors that contribute to weight problems, but also the need to elucidate the neurobiological mechanisms of the self-regulatory failure over eating that leads to weight problems. Emergent findings suggest an overlapping model of addiction and compulsive overeating.
OBJECTIVE: Our goal was to examine whether neural hyper-responsivity to reward typically associated with substance abuse could also be seen in individuals exhibiting binge-eating behavior.
DESIGN: Participants completed self-assessments of demographic information and eating behavior. Neurofunctional data were collected via functional MRI (fMRI) scans while participants were exposed to personally relevant high-calorie cues.
SETTING: The participants were recruited from the general community. PARTICIPANTS: Twenty-six individuals with high body mass index (BMI)>25 and moderate binge-eating behavior as assessed by the Binge Eating Scale (BES) were recruited for this study. MAIN OUTCOME MEASURES: fMRI BOLD response during exposure to high-calorie taste cues.
RESULTS: The results showed that exposure to high-calorie taste cues elicited fMRI BOLD response in the reward system of individuals with high BMI, and, more importantly, that this hyper-responsivity increases with greater number of binge-eating symptoms (cluster-corrected p<.05, z=1.9).
CONCLUSIONS: These findings support an overlapping neural model of addiction and self-regulatory failure over eating that may lead to problems with weight in humans. These findings offer insight into the prevention and treatment of disordered eating.