4 - (SYM 100) Emotion Regulation Strategy Use Longitudinally Predicts Next Day Binge Eating, Purging, and Dieting Through Changes in Affect

Background: Trait-level emotion regulation (ER) difficulties are associated with eating disorders (EDs) transdiagnostically. However, almost no research has examined whether ER longitudinally predicts ED behaviors in daily life or the mechanisms of ER effects. We used a daily diary design spanning 49 days to examine whether day-to-day changes in adaptive (e.g., cognitive reappraisal) and maladaptive (e.g., rumination) ER strategy use predicted same-day and next-day engagement in core ED behaviors (binge eating [BE], purging, and dieting). We also examined the mechanisms of ER effects by testing whether longitudinal associations with ED behaviors were mediated by changes in affect.

Methods: Female twins (N = 688) ages 15-30 from the population-based Michigan State University Twin Registry reported their use of adaptive and maladaptive ER strategies, negative affect (NA) and positive affect (PA), and engagement in BE, purging, and dieting on 49 consecutive days. We used probit structural equation models to examine whether within-person fluctuations in ER predicted same- and next-day ED behaviors and whether associations between ER and next-day ED behaviors were mediated by ER effects on next-day affect.

Results: Adaptive and maladaptive ER showed differential associations with ED behaviors. Greater use of maladaptive ER was associated with greater likelihood of same-day BE and next-day BE and purging. Mediation analyses showed the impact of maladaptive ER on next-day BE and purging was mediated by greater next-day NA. In contrast, adaptive ER was unrelated to BE and purging on the same or next day. However, adaptive ER predicted greater next-day PA, which was in turn associated with greater likelihood of next-day dieting.

Conclusions: ER strategy use longitudinally predicts engagement in ED behaviors and may be an important maintaining mechanism for EDs. Interventions focused on decreasing maladaptive ER and subsequent NA could potentially help disrupt cycles of BE and purging. Conversely, results add to evidence that fluctuations in PA may play a unique role in maintaining restrictive behaviors, potentially due to increased motivation to diet when PA is high.