A naturalistic examination of the temporal patterns of affect and eating disorder behaviors in anorexia nervosa

Objective Evidence supports the presence of significant variability in the timing of affective experiences and eating disorder (ED) behaviors across ED populations. This study examined the naturalistic timing of affective states and ED behaviors in anorexia nervosa (AN). Methods Women (N = 118) with full or subthreshold DSM-IV AN completed 2 weeks of ecological momentary assessment (EMA) involving self-reports of affect and ED behaviors. Patterns of positive affect, negative affect, and tension/anxiety across hours of the day and days of the week were examined using linear mixed models. Variation in ED behavior occurrence (i.e., binge eating, vomiting, exercise, meal skipping, and self-weighing) across hours of the day and days of the week was examined using general estimating equations. Results Results revealed significant variation in tension/anxiety across hours of the day; there were no significant associations between time of day and negative or positive affect. All affective variables significantly varied across days of the week, with both negative affect and tension/anxiety highest in the middle of the week and lowest on the weekends. The ED behaviors all significantly varied across hours of the day, with binge eating and vomiting most common in later hours, exercise and self-weighing most common in earlier hours, and meal skipping most common at times corresponding to breakfast and lunch. ED behaviors did not significantly vary across days of the week. Conclusion The significant patterns of variation in the timing of affective experiences and ED behaviors may have utility in informing theories and interventions for AN.