Increased dorsolateral prefrontal cortex activation in obese children during observation of food stimuli.

Objective: Food cues yield different patterns of brain activation in obese compared with normal-weight adults in prefrontal and limbic/paralimbic areas. For children, no mapping studies comparing representation sites for food and other stimuli between obese and normal-weight subjects are available.

Design: We used a cross-sectional design of two age-matched subject groups to investigate differences in brain activation in response to visually presented food, pleasant, and neutral pictures between obese/overweight and normal children.

Subjects: 22 overweight/obese children were compared with 22 normal-weight children.

Measurements: Functional magnetic resonance imaging (of the whole head during perception of visually presented stimuli), psychological testing, and psychophysical measures of heart rate deceleration were assessed.

Results: Obese children showed higher activation of the dorsolateral prefrontal cortex (DLPFC) in response to food pictures. In addition, DLPFC activation was negatively correlated with self-esteem. In contrast, normal-weight children showed higher activation of the caudate and hippocampus specific to food pictures, and of the anterior cingulate cortex and thalamus to visual cues in general. In response to food stimuli, obese children showed a heart rate deceleration correlating positively with activation of the ventrolateral prefrontal cortex.

Conclusion: Obese children react to food stimuli with increased prefrontal activation, which might be associated with increased inhibitory control.