Abstract
BACKGROUND: Social support helps prevent the onset and progression of overeating. However, few studies have explored the neural mechanisms underlying this pathway. This study used functional magnetic resonance imaging (fMRI) and dynamic causal modeling (DCM) analysis to elucidate the general neural mechanisms and effective neural pathways linking social support to alterations in food cue processing and overeating. METHODS: This study included 58 healthy, premenopausal female participants (mean age, 20.92 years), divided into social support (SS) and non-social support (NSS) groups. Participants underwent fMRI scans while performing the Food Incentive Delay (FID) task. We investigated group differences in brain activation and effective connections, as well as correlations with food consumption. RESULTS: When exposed to food cues, the SS group showed increased activation in the Executive Control Network (ECN), Salience Network, and Reward Network, specifically in response to high-calorie foods in the ECN. DCM analysis demonstrated enhanced excitatory effects in the SS group, including pathways from the right caudate to the right insula, right insula to right DLPFC, and left putamen to left VMPFC, under high-calorie conditions. The effective connectivity between the caudate and insula was negatively correlated with food choices. CONCLUSION: Social support modulates a bottom-up neural pathway connecting intrinsic networks related to reward sensitivity, emotional salience, and inhibitory control, which helps suppress excessive cravings and intake of high-calorie foods. This study provides the first neural evidence for a shared neural basis between social reward and food reward.