Examining intra-individual variability in food-related inhibitory control and negative affect as predictors of binge eating using ecological momentary assessment.

Binge eating presents in the context of several eating disorders (EDs) and has been shown to be associated with negative affectivity and inhibitory control deficits. While considerable ecological momentary assessment (EMA) work in EDs has demonstrated the importance of intra-individual variability in affect in predicting binge episodes, no research has considered how fluctuations in inhibitory control and negative affect together influence binge eating, or the extent to which these relationships may differ across ED diagnoses. Therefore, the present EMA study assessed the extent to which daily inhibitory control moderated momentary associations between negative affect and binge eating, and whether the presence of regular compensatory behaviors influenced these associations. Participants were 40 women reporting regular binge eating (anorexia nervosa binge-purge type [AN-BP], bulimia nervosa [BN], binge-eating disorder [BED]/subthreshold BED) who completed a 10-day EMA protocol that included measures of affect, eating, and a daily ambulatory Go/No-go task that included palatable food and neutral stimuli. Results of generalized estimating equations indicated greater between-person food-related inhibitory control deficits were associated with greater binge likelihood, and there was a three-way interaction between momentary negative affect, daily food-related inhibitory control, and compensatory behavior group. For individuals with BN or AN-BP, the relationship between momentary negative affect and subsequent binge eating was stronger on days characterized by reduced inhibitory control, whereas no main or interactive effects of negative affect or inhibitory control were observed for those with BED/subthreshold BED. Together these results demonstrate the importance of intra-individual variability in executive functioning and affective processes that underlie binge eating, as well as meaningful individual differences in these momentary associations.