BackgroundConflicting results have been reported regarding the predictive value of preoperative psychological assessment and weight outcome after bariatric surgery. This might be attributed to different factors affecting early weight loss and long-term weight loss. Herein, we investigated whether preoperative psychiatric profile was associated with preoperative BMI and with both early (1 year) and long-term (5 years) weight loss after Roux-en-Y gastric bypass (RYGB).MethodsProspective observational cohort study of patients undergoing RYGB between 2013 and 2019. Symptoms related to anxiety, depression, eating disorder, and alcohol use disorders were assessed by employing validated, specific psychometric tests (STAI-S/T, BDI-II, BITE, AUDIT-C) prior to surgery. Pre-operative BMI, early weight loss (1 year), and long-term weight evolution (up to 5 years) were registered.ResultsTwo hundred thirty six patients (81% women) were included in the present study. Linear longitudinal mixed model showed a significant effect of preoperative high anxiety (STAI-S) on long-term weight outcome, after controlling for gender, age and type 2 diabetes. Patient with high preoperative anxiety score regained weight faster than those experiencing low anxiety (each year percent excess BMI loss (%EBMIL) − 4.02%, ± 1.72,p= 0.021). No other pre-operative psychiatric symptoms have been shown to have an impact on long-term weight loss. In addition, no significant association was found between any of the pre-operative psychiatric variables and pre-operative BMI, or early weight loss (%EBMIL) at 1-year post-RYGB.ConclusionHerein we identified high anxiety score (STAI-S) as a predictor for long-term weight regain. Thus, long-term psychiatric surveillance of these patients and the development of tailored management tools could serve as a means to prevent weight regain.Graphical abstract