The effective neural connections in food inhibitory control and their relationship with daily eating behavior in individuals with overweight/obesity or normal-weight

This study investigates the differences in effective neural connections during food inhibitory control between individuals with overweight/obesity (OW/OB) and those with normal weight (NW), and examines how these neural differences relate to daily eating behaviors. Fifty-one female participants were classified into OW/OB (BMI ≥ 25 kg/m²) or NW (BMI 18–22 kg/m²) groups. Participants completed a modified food-specific go/no-go task with working memory load during fMRI scanning. Neural connectivity was analyzed using dynamic causal modelling (DCM). Ecological momentary assessment (EMA) was used to collect real-time data on eating behaviors over one week. The OW/OB group showed lower accuracy in responding to low-calorie food cues and greater activation in the left hippocampus during no-go trials with high-calorie foods. DCM revealed stronger excitatory connectivity from the right inferior frontal gyrus (IFG) to the medial prefrontal cortex (mPFC), and stronger inhibitory connectivity from the mPFC to the dorsal caudate, as well as from the dorsal caudate to the left hippocampus in the OW/OB group. EMA results indicated that the OW/OB group was more likely to succumb to food desires between 13:00 and 17:00. Mediation analysis confirmed that effective connectivity mediated the relationship between task performance and daily eating behaviors. These findings elucidate the neural mechanisms underlying food inhibitory control in OW/OB individuals, highlighting the role of the hippocampus and the IFG–mPFC circuit. The study provides theoretical advances within the dual-system framework and suggests that targeting these neural pathways may improve dietary control in obesity.