OBJECTIVES Bariatric surgery is an effective treatment for youth with severe obesity. However, outcomes are variable and there remains sparse understanding of predictors of weight loss following surgery. The current study examines the role of adolescent-reported pre-operative social support around exercise, binge eating, and exercise to predict excess body mass index (EBMI) loss from 3 to 12 months post-surgery. METHOD Participants were 101 adolescents ages 12-21 (M age = 16.6, SD = 1.8). Pre-operative body mass index (BMI) ranged from 35 to 87 (M = 50.3, SD = 8.6). Structural equation modeling (SEM) was used to evaluate a model of the association of adolescent report of perceived social support for exercise with less binge eating (items from the Eating Disorder Diagnostic Scale) and more self-reported exercise (items from the Youth Risk Behavior Surveillance System). The model was used to predict EBMI loss at 3, 6, 9, and 12 months post-surgery. RESULTS Social support significantly predicted exercise and demonstrated a trend for predicting binge eating, such that more social support was associated with more exercise and a trend for less binge eating. Binge eating was associated with less EBMI loss. However, there was no association of exercise with EBMI loss. CONCLUSIONS Pre-operative binge eating should be a target for identification and treatment prior to sleeve gastrectomy in adolescents. Although not directly or indirectly associated with EBMI loss, perceived social support around exercise was associated with increased exercise, which may make it a consideration for a target for intervention as well.