Greater corticolimbic activation to high-calorie food cues after eating in obese vs. normal-weight adults

The goal of this research is to identify the neural response to rewarding food cues before and after eating in overweight/obese (OB) and normal-weight (NW) adults. Based on the previous literature, we expected greater differential activation to food cues vs. objects for OB compared to NW participants both prior to eating and after consumption of a typical lunch. Twenty-two overweight/obese (11 male) and 16 normal-weight (6 male) individuals participated in a functional magnetic resonance imaging task examining neural response to visual cues of high- and low-calorie foods before and after eating. The OB group demonstrated increased neural response to high- and low-calorie foods after eating in comparison to the NW participants in frontal, temporal, and limbic regions. In addition, greater activation in corticolimbic regions (lateral OFC, caudate, anterior cingulate) to high-calorie food cues was evident in OB vs. NW participants after eating. These findings suggest that for OB individuals, high-calorie food cues show sustained response in brain regions implicated in reward and addiction even after eating. Moreover, food cues did not elicit similar brain response after eating in the NW group suggesting that neural activity in response to food cues diminishes with reduced hunger for these individuals.

► Functional MRI was used to examine brain response to food before and after eating.
► Obese showed greater brain response to food cues after eating than normal-weight.
► Increased response of OFC, caudate, and anterior cingulate after eating in obese.
► Corticolimbic response after eating implies continued salience of high-calorie food.
► Activity in response to food cues in normal weight diminishes with reduced hunger.