Dietary Restriction Behaviors and Binge Eating in Anorexia Nervosa, Bulimia Nervosa and Binge Eating Disorder: Trans-diagnostic Examination of the Restraint Model.

OBJECTIVE To compare dietary restriction behaviors among adults with eating disorders involving binge eating, including anorexia nervosa-binge/purge subtype (AN-BE/P), bulimia nervosa (BN), and binge eating disorder (BED), and to examine whether dietary restriction behaviors impact binge eating frequency across diagnoses. METHOD Participants included 845 treatment seeking adults (M=30.42+10.76years) who met criteria for DSM-5 AN-BE/P (7.3%;n=62), BN (59.7%;n=504), and BED (33.0%;n=279). All participants self-reported their past and current eating disorder symptoms on the Eating Disorder Questionnaire. RESULTS Adults with AN-BE/P and BN reported significantly more dietary restriction behaviors (e.g. eating fewer meals per day, higher frequency of fasting, consuming small and low calorie meals) in comparison to adults with BED. Adults with AN-BE/P and BN who reported restricting food intake via eating fewer meals per day had more frequent binge eating episodes. However, adults with BN who reported restricting food intake via eating small meals and low calorie meals had less frequent binge eating episodes. DISCUSSION This study provides mixed support for the restraint model by suggesting that not all dietary restriction behaviors are associated with higher levels of binge eating. It may be that adults with BN who report a higher frequency of eating small and low calorie meals display more control over their eating in general, and therefore also have lower frequency of binge eating. Clinicians should assess for dietary restriction behaviors at the start of treatment prior to assuming that all forms of strict dieting and weight control behaviors similarly impact binge eating.