The impact of neural responses to food cues following stress on trajectories of negative and positive affect and binge eating in daily life.

Stress and affect have been implicated in the maintenance of binge eating for women with symptoms of bulimia nervosa (BN). Neuroimaging and ecological momentary assessment (EMA) have separately examined how these variables may contribute to eating disorder behavior. Though both methodologies have their own strengths, it's unclear how either methodology might inform the other. This study examined the impact of individual differences in neural reactivity to food cues following acute stress on the trajectories of positive affect (PA) and negative affect (NA) surrounding binge eating. Women (n = 16) with BN symptoms viewed palatable food cues before and after a stress induction in the scanner. For two weeks, participants responded to prompts assessing affect and binge episodes several times a day. EMA data revealed NA increased and PA decreased before binge episodes in the natural environment. Additionally, NA decreased while PA increased following binge episodes. Changes in activation in the ACC, amygdala, and the vmPFC significantly moderated the relationship of affect to binge eating. However, lateral differences of each brain region uniquely moderator the trajectory of PA, NA, or both to binge eating. Specifically, those with less change in BOLD response reported significantly increasing NA and decreasing PA prior to binges, while women with greater decreases reported no change in affect. Following binge eating, individuals with decreased change in BOLD response reported decreasing NA and increasing PA. This may suggest individual differences in neural response to food cues under stress appear to underlie affect driven theory on the antecedents to binge eating.