Evaluating the roles of anxiety and dimensions of perfectionism in dieting and binge eating using weekly diary methodology.

This study examined the relations between weekly reports of anxiety, dimensions of trait perfectionism, and dieting and binge eating over the course of 11 weeks. Participants were 406 college women who completed a battery of questionnaires at Time 1 that assessed trait-like characteristics (e.g., self-oriented and socially prescribed perfectionism). For 11 weeks following that, participants filled out a short questionnaire packet that assessed their weekly anxiety, dieting, and binge eating. Using multilevel modeling, results indicated that on average, both within- and between-person levels of anxiety predicted increased binge eating, while only between-person levels of anxiety predicted increased dieting. Higher levels of self-oriented perfectionism also predicted increased dieting and binge eating, while higher levels of socially prescribed perfectionism predicted increased binge eating only (not increased dieting). The relation between weekly anxiety and disordered eating was not moderated by either dimension of perfectionism. Results provide support for the notion that dieting is generally affected by trait-like characteristics, while binge eating is generally affected by both trait- and state-like characteristics; these findings have significant clinical implications.