Abstract P091: Food-Stimulated Neuronal Activation Differs by Feeding Status in Obese and Normal-Weight Women: An fMRI Study
Introduction: Neurological responses to food stimuli are complex and differ between lean, obese, and post-obese (weight-reduced) individuals. However, the neurological systems that regulate feeding in relation to weight status are not understood. The purpose of this study was to compare satiety mechanisms (fed>fasted) in obese and lean women.
Hypothesis: We assessed the hypotheses that food-specific neural signals affected by satiety are more active in lean than obese women.
Methods: Eleven normal weight (BMI 22.8 ± 1.5 kg/m2) and 9 obese (BMI 33.0 ± 3.4 kg/m2) women completed a functional magnetic resonance imaging (fMRI) study. Fasted state scans were performed after an 8-h daytime fast for normal weight women whereas obese women were scanned after an overnight fast. Fed state scans were started 30 min after consumption of a liquid meal replacement providing 35% of resting energy requirements. Testing days were held 2 wk apart.
Results: Overall, the neuronal activity in response to food stimuli was higher in the fed state than the fasted state for both groups. However, normal weight women had a greater number of activated regions than obese women in both the fed and fasted state. When fed and fasted states were contrasted (fed>fasted) and compared between groups (normal weight>obese), normal weight women had greater activation in the insula, cuneus, lingual gyrus, pre- and post-central gyrus, superior and middle temporal gyrus, and inferior frontal gyrus in the fed state than the obese.
Conclusions: In conclusion, the findings of this study suggest that obese individuals recruit fewer brain centers in response to food stimuli when fed. This may be associated with a reduced ability to respond to internal satiety signals.
Author Disclosures: M. Sy: None. M.S. Kim: None. J. Hirsch: None.
- © 2014 by American Heart Association, Inc.