Differences in affect regulation abilities among dietary- and dietary-negative affect subtypes of binge eating disorder: Implications for conceptualization and treatment

History and Rationale. Cluster-analytic studies of binge eating disorder (BED) have yielded 2 subtypes (pure dietary and mixed dietary-negative affect). Within the construct of a dual-pathway model, these subtypes are thought to conform to the dietary restraint model and affect regulation model of BED, respectively. While these studies have identified disparate levels of dietary restraint, depression, and self-esteem between the two subtypes, affect regulation has not been comparatively evaluated. Objective. The current study aimed to identify differences in affect regulation between subtypes to explore the fit of the dual-pathway model. The current study also examined change in affect regulation after treatment with 20 sessions of group dialectical behavioral therapy (DBT) adapted for BED. The study further explored the relationship between improvement in affect regulation abilities and reduction in binge eating for each of the two subtypes. Methods. This study examined affect regulation abilities of 48 individuals with BED clustered into dietary (N=27) and dietary-negative affect (N=19) subtypes, both at baseline and after treatment with DBT. Results. Individuals in the dietary-negative affect subtype had significantly higher levels of difficulty in affect regulation than those in the dietary subtype at baseline. Both subtypes exhibited significant improvement in affect regulation abilities after treatment with DBT. A positive relationship was found between improvement in affect regulation abilities and reduction in total binge eating (objective binge episodes plus subjective binge episodes) in the dietary-negative affect subtype as well as for the treatment group as a whole, but not within the dietary subtype. Implications. Findings support the use of the dual-pathway model in understanding subtypes of BED. Results further support the use of individualized treatment for the two subtypes of BED, with results suggesting that the dietary-negative affect subtype benefits from treatment that directly addresses affect regulation.