SummaryIntroductionMultiple factors are related to lower weight loss after bariatric surgery. This review and meta‐analysis evaluates the influence of several mental and behavioral factors on weight loss.MethodSix electronic databases were searched. Percentage excess weight loss (%EWL) was calculated for all moderator and non‐moderator groups of the variables: symptoms of depression, anxiety and binge eating, compliance, physical activity, quality of life, and body image. All moderators, surgery types, and follow‐up moments were analyzed separately.ResultsIn total, 75 articles were included in the review; 12 meta‐analyses were conducted. Higher postoperative compliance to follow‐up was associated with 6.86%–13.68% higher EWL. Preoperative binge eating was related to more weight loss at 24‐ and 36‐month follow‐up (7.97% and 11.79%EWL, respectively). Patients with postoperative binge eating symptoms had an 11.92% lower EWL. Patients with preoperative depressive symptoms lost equal weight compared to patients without symptoms.ConclusionDespite the high heterogeneity between studies, a trend emerges suggesting that the presence of postoperative binge eating symptoms and lower postoperative compliance may be associated with less weight loss after bariatric‐metabolic surgery. Additionally, preoperative depressive symptoms and binge eating do not seem to significantly impact weight loss.