Bariatric Surgery for Patients with Overweight/Obesity. A Comprehensive Grading Methodology and Network Metanalysis of Randomized Controlled Trials on Weight Loss Outcomes and Adverse Events

his study aims to compare different types of metabolic bariatric surgery (MBS) with lifestyle intervention/medical therapy (LSI/MT) for the treatment of overweight/obesity. The present and network meta-analysis (NMA) includes randomized trials. MBS was associated with a reduction of BMI, body weight, and percent weight loss, when compared to LSI/MT, and also with a significant reduction of HbA1c and a higher remission of diabetes. Meta-regression analyses revealed that BMI, a higher proportion of women, and a longer duration of trial were associated with greater effects of MBS. The NMA showed that all surgical procedures included (except greater curvature plication) were associated with a reduction of BMI. MBS is an effective option for the treatment of obesity. The choice of BMI thresholds for eligibility for surgery of patients with different complications should be performed making an evaluation of risks and benefits in each BMI category.