Obesity moderates the appetite-mediated association between approach bias and food choice

The global obesity epidemic necessitates a comprehensive understanding of the cognitive and motivational processes underlying unhealthy eating behaviors. This study investigated whether obesity moderates the indirect effect of automatic approach bias toward high-calorie foods on food choice, mediated by subjective appetite. A total of 164 participants (83 normal-weight and 81 with obesity) were recruited. Participants completed a joystick-based Approach-Avoidance Task to assess approach bias for high-calorie foods, a Food Choice Task to evaluate the selection of unhealthy items, and visual analog scales to calculate subjective appetite. A moderated mediation analysis was performed. The moderated mediation analysis revealed that obesity significantly moderated the relationship between approach bias and subjective appetite (β = 0.648, p < 0.001), and between approach bias and food choice (β = 0.398, p = 0.018). Simple slope analyses showed that approach bias was positively associated with subjective appetite and food choice only in the obesity group (both ps < 0.001). Crucially, the indirect effect of approach bias on food choice via subjective appetite was significant only in the obesity group (β = 0.220, 95% Boot CI: [0.092, 0.384]), but not in the normal-weight group (β = 0.031, 95% Boot CI: [-0.028, 0.125]). Among individuals with obesity, a stronger automatic approach bias towards high-calorie foods was associated with increased subjective appetite, which in turn was associated with the selection of more unhealthy foods. These findings illuminate an obesity-specific cognitive-affective pathway and emphasize the potential for targeted interventions aimed at modifying approach bias and managing appetite within this population.