Differential Reward Response to Palatable Food Cues in Past and Current Dieters: A fMRI Study

Objective: Prior neuroimaging research has shown that restrained and unrestrained eaters demonstrate differential brain activation in response to food cues that parallels their food intake in lab studies. These findings were extended by comparing brain activation in response to food cues in normal weight nondieters, historical dieters, and current dieters under the conditions that mimicked past lab studies. Methods: Participants (N 5 30) were shown pictures of highly and moderately palatable food and neutral cues while being scanned in an fMRI BOLD paradigm following an 8- h fast and again after a liquid meal. Results: In the Fed state, historical dieters showed elevated reward circuitry activation in response to highly palatable food, as compared to nondieters and current dieters. In contrast, current dieters did not show the same pattern of activation as historical dieters, despite their shared history of frequent weightloss dieting. Conclusions: The parallels between eating behavior and regional brain activation across groups suggest that (1) a neurophysiological response which could represent a vulnerability to overeat exists in some normal weight young women that may increase susceptibility to weight gain in the long term, and (2) current dieting temporarily reverses this vulnerability.