1 - (SYM 49) The Role of Affect in the Maintenance of Restrictive Eating Behaviors in Atypical Anorexia Nervosa: Comparisons to Anorexia Nervosa and Bulimia Nervosa

Although affective states have been implicated in maintenance of eating disorder behaviors, few ecological momentary assessment (EMA) studies have examined the role of affective states in the maintenance of restrictive eating behaviors. Importantly, no studies have considered whether affective states prompt restrictive eating behaviors in individuals with atypical anorexia nervosa (atypical AN) or compared affective changes prior to and following restrictive eating across different eating disorder diagnoses, including atypical AN. This study investigated the role of affective states in restrictive eating behaviors across diagnoses. Women with atypical AN (n = 21), anorexia nervosa-restrictive subtype (AN-R, n = 24), anorexia nervosa-binge eating/purging subtype (AN-BP, n = 27), and bulimia nervosa (n = 52) completed diagnostic interviews and then completed 14 days of EMA, including five daily signal-contingent surveys assessing affect and skipped meals and event-contingent surveys upon eating that assessed restriction. Across diagnoses, individual differences in negative and positive affect predicted restrictive eating, but momentary affect ratings did not predict restrictive eating at the next time point. Both individual differences and momentary fluctuations in negative affect predicted skipped meals, but only individual differences in positive affect predicted skipping meals. While participants reported higher positive affect after skipping meals compared to moments they did not report skipping a meal, there were no differences in affect ratings following restrictive and non-restrictive eating episodes. Diagnosis did not moderate any of these results. Our findings partially support the emotional avoidance model of restriction and suggest that restrictive eating behaviors, especially skipping meals, can serve to avoid negative affective states and enhance positive affect.