Neural dissociation between liking and wanting in successful versus unsuccessful restrained eaters: Brain responses to wanting are associated with daily dietary control.

This study aimed to explore the differences in reward processing between successful (SREs) and unsuccessful restrained eaters (UREs) within the 'liking-wanting' framework, and to examine how these neural differences are associated with daily dietary control in the real world. Fifty-eight restrained eaters were classified into 28 SREs and 30 UREs based on the Dutch Eating Behavior Questionnaire. During a functional magnetic resonance imaging (fMRI) scan, participants rated high- and low-calorie food images for liking (hedonic value) and wanting (incentive value). Subsequent real-world eating behaviors were tracked over one week using ecological momentary assessment (EMA). Behaviorally, SREs reported lower wanting ratings for foods compared to UREs, as supported by a significant rating type×group interaction, with no group difference in liking ratings. Neurally, small-volume correction within predefined reward-related regions of interest revealed that UREs exhibited heightened activation in the left putamen, left insula, and right caudate during wanting for high-versus low-calorie foods, whereas no significant group differences were detected in the neural correlates of liking. UREs also showed enhanced task-modulated functional connectivity between the left putamen and nucleus accumbens. Exploratorily, these neural responses in wanting-related circuitry were associated with daily dietary control: greater right caudate activation was associated with reduced resistance to food desires, and both caudate activation and heightened striatal connectivity were associated with a larger amount of food consumed. The findings suggest that heightened wanting-related brain activity which distinguishes UREs from SREs correlates with poorer dietary control at the individual level. These results identify neural correlates of motivational wanting that differ between the two groups and are associated with daily dietary control across all participants, positioning the motivational wanting system as a key neural substrate for understanding unsuccessful dietary restraint.