What About My Weight? Insufficient Weight Loss or Weight Regain After Bariatric Metabolic Surgery

Context: This review study aimed to investigate the definition, etiology, risk factors (RFs), management strategy, and prevention of insufficient weight loss (IWL) and weight regain (WR) following bariatric metabolic surgery (BMS). Evidence Acquisition: Electronic databases were searched to retrieve relevant articles. The inclusion criteria were English articles with adult participants assessing the definition, prevalence, etiology, RFs, management strategy, and prevention of IWL/WR. Results: Definition: The preferred definition for post-BMS IWL/WR are the terms "Lack of maintenance of total weight loss (TWL)>20%" and "weight change in percentage compared to nadir weight or weight loss". Prevalence: The exact prevalence of IWL/WR is still being determined due to the type of BMS and various definitions. Etiology: Several mechanisms, including hormonal/metabolic, dietary non-adherence, physical inactivity, mental health, and anatomic surgical failure, are possible etiologies of post-BMS IWL/WR. RFs: Preoperative body mass index (BMI), male gender, psychiatric conditions, comorbidities, age, poor diet, eating disorders, poor follow-ups, insufficient physical activity, micronutrients, and genetic-epigenetic factors are the most important RFs. Management Strategy: The basis of treatment is lifestyle interventions, including dietary, physical activity, psychological, and behavioral therapy. Pharmacotherapy can be added. In the last treatment line, different techniques of endoscopic surgery and revisional surgery can be used. Prevention: Behavioral and psychotherapeutic interventions, dietary therapy, and physical activity therapy are the essential components of prevention. Conclusions: Many definitions exist for WR, less so for IWL. Etiologies and RFs are complex and multifactorial; therefore, the management and prevention strategy is multidisciplinary. Some knowledge gaps, especially for IWL, exist, and these gaps must be filled to strengthen the evidence used to guide patient counseling, selection, and improved outcomes.