Neural Mechanisms Mediating the Effects of Food Cues and Acute Exercise

The obesity epidemic is imposing enormous costs on individuals and on developed and developing societies. Ultimately, obesity arises from a sustained imbalance in the energy balance equation from either excessive energy consumption or significantly reduced activity. Here we report on findings from two fRMI studies, each of which examines one side of the energy balance equation. In our first study, the Passive Viewing of Foods, we examined the effects of acute exercise on self-report measures of appetite suppression and on neural activity resulting when normal BMI subjects viewed blocks of high calorie or low calorie food cues. We found that acute exercise suppressed self-reported appetite and reduced the activation of two key brain areas relative to appetite regulation: the dorsal anterior cingulate (dorsal ACC), a frontal attention processing area, and the nucleus accumbens, a central reward processing area. Moreover, we conducted functional connectivity analysis to examine other areas of the brain that were positively or negatively correlated with these two areas when viewing high calorie food cues following exercise. The functional network identified was broadly distributed and