Structural integrity between executive control and reward regions of the brain predicts body fat percentage in chronic dieters.

Failure to maintain a healthy body weight may reflect a long-term imbalance between the executive control and reward systems of the brain. The current study examined whether the anatomical connectivity between these two systems predicted individual variability in achieving a healthy body weight, particularly in chronic dieters. Thirty-six female chronic dieters completed a food-cue reactivity task in the scanner. Two regions-of-interest (ROIs) were defined from the reactivity task: the inferior frontal gyrus (IFG), which engages cognitive control and the orbitofrontal cortex (OFC), which represents reward value. A white matter tract connecting these two ROIs was identified across participants using diffusion tensor imaging (DTI) and probabilistic tractography. Results showed a negative relationship between body fat percentage and white matter integrity within the identified tract. This suggests that reduced structural integrity between the OFC and IFG may be related to self-regulatory problems for those who chronically diet to control body weight.