Neural correlates of inhibitory control during a simple food go/no-go task in adolescents varying in familial obesity risk.

Maternal obesity increases the risk of offspring obesity but neurobehavioral mechanisms are not well understood. Using a simple fMRI task to minimize the contribution of task demands to group differences, we investigated food-related inhibitory control and underlying neural circuits in 71 14-18y olds (33M, 38F), of whom n = 22 were lean with a lean biological mother (lean low-risk, 'lean-LR'), n = 19 lean with a biological mother with obesity/overweight (lean high-risk, 'lean-HR'), and n = 30 with obesity/overweight ('overweight'). On two separate days, under fasted (474 ml 0 kcal water preload before scan) and fed (474 ml 480 kcal milkshake before scan) conditions (counter-balanced), participants underwent a food go/no-go fMRI task where the 'go' trial stimulus was a picture of broccoli, and the 'no-go' trial stimulus was a picture of either French fries or vanilla ice cream, followed by a multi-item ad libitum meal test. In both fasted and fed conditions, 'no-go' trials robustly activated a well-established inhibitory circuit including frontal, temporal and occipital gyri, insula and cerebellum. During 'no-go' trials, the lean-HR vs. lean-LR group showed a pattern of greater engagement of frontocingulate and parietal regions (e.g. middle and superior frontal gyrus, anterior cingulate cortex, inferior parietal cortex) along with deactivation of default mode regions (cuneus, posterior cingulate cortex) and greater caudate activation. Response variability and superior frontal gyrus responses during 'no-go' trials were positively associated with ad libitum meal intake. Our results suggest that raised obesity risk as indicated by higher maternal BMI may be associated with increased engagement of inhibitory circuits and striatal reward regions during a simple food-related inhibition task, potentially reflecting greater effort required to inhibit appetitive responses to food.