Lifetime stressor exposure, eating expectancy, and acute social stress-related eating behavior: A pre-registered study of the emotional eating cycle.

Eating behaviors in response to acute stressors are highly variable: whereas many individuals eat more following stressors, others eat less or show no change in food consumption. Understanding factors that predict individual differences in eating behaviors may help elucidate the psychosocial mechanisms underlying obesity, yet few experimental studies on this topic have been conducted to date. To address this issue, we conducted the present pre-registered study, where we investigated how lifetime stressor exposure moderates the extent to which eating expectancies enhance the learned association between stress-induced negative affect and snack intake. Participants were 44 women (30% non-White) between 18 and 50 years old (M = 27.9), with a mean body mass index of 25.6, who completed assessments of lifetime stressor exposure, eating behaviors, and eating expectancies (eating helps manage negative affect); in a subsequent visit, they were given snacks after an acute social stress task (TSST). The moderated moderation model (PROCESS model 3) yielded a significant three-way interaction. When eating expectancies were high, acute social stress-induced negative affect predicted greater M&M intake for women with very high total lifetime stressor exposure but less M&M intake for women with fewer lifetime stressors. These data thus highlight how lifetime stressor exposure interacts with eating expectancies and acute stress-induced negative affect to predict eating behavior. Replications in larger samples may help explain variability in stress-eating as well as how lifetime stressors contribute to obesity.