(PS5-43) An Examination of Different Motivations for Dietary Restraint Among Individuals with Bulimia Nervosa

Abstract Text: Bulimia nervosa (BN) is characterized by recurrent binge eating and compensatory behaviors driven by rigid cognitive rules about eating and concerns about weight. The Drive for Thinness (DFT) subscale of the Eating Disorder Inventory (EDI) is commonly used to assess motivation for dietary restraint. However, prior research suggests that the DFT may primarily measure a fear of weight gain similar to the Goldfarb Fear of Fat Scale (GFFS), rather than a desire to attain an objectively thin body weight. The Drive for Objective Thinness (DFOT) scale was developed to assess the distinct motivation to reach a body weight 15% below a medically ideal weight and has been shown to distinguish individuals with BN from non-clinical restrained and unrestrained eaters. Despite these findings, the DFOT remains underutilized in BN research. This study examined relationships among DFOT, DFT, and GFFS and their associations with eating disorder (ED) psychopathology in individuals with BN. We hypothesized that DFOT would show stronger relationships with psychological, eating and weight-related symptoms of ED compared to DFT and GFFS. Female adults with BN or subthreshold BN (N = 91) completed measures assessing ED psychopathology and weight history. Psychological symptom measures included the Eating Disorder Examination (EDE) subscales and global score and EDI subscales of Bulimia and Body Dissatisfaction. Eating and weight-related variables included BMI, traditional and developmental weight suppression, binge eating frequency, average binge calories, and purging frequency. Correlational analyses showed moderate associations between DFOT and DFT (r = .42, p < .001), DFOT and GFFS (r = .53, p <.001), and DFT and GFFS (r = .59, p <.001). Regression analyses including DFOT/DFT or DFOT/GFFS models revealed that all measures of dieting motivation independently and significantly predicted EDE global score and most subscales. Only DFOT significantly predicted developmental weight suppression (β = -.01, p = .03), BMI (β = .06, p = .04), and average calories consumed during a binge episode (β = -.01, p = .05). Findings suggest that current weight, weight history, and binge size are independently related to a desire to reach an objectively thin body weight in individuals with BN. The results suggest that the DFOT is uniquely related to BN features of substantial clinical concern. This indicates that the DFOT should be used instead of, or along with, DFT or GFFS in studies of ED psychopathology.