Insufficient weight loss occurred in 27% of patients post-bariatric surgery, with RYGB associated with a reduced risk (RR = 0.71) compared to SG, influenced by preoperative comorbidities.
What are the definitions and predictors of insufficient weight loss after primary metabolic bariatric surgery?
Insufficient weight loss after bariatric surgery is common and primarily driven by preoperative metabolic comorbidities, though Roux-en-Y gastric bypass appears to confer a protective effect.
Absolute Event Rate: 0% vs 0%
Abstract Background Metabolic and bariatric surgery (MBS) is the most effective long-term treatment for severe obesity and its comorbidities. However, a subset of patients experiences insufficient weight loss (IWL)—a poorly defined outcome that undermines the long-term success of surgery and its metabolic benefits. Definitions of IWL vary widely, ranging from 50% excess weight loss (%EWL) to 20% total weight loss (%TWL), complicating study comparisons and predictive modelling. This systematic review and meta-analysis aimed to (1) assess how IWL is defined in the literature and (2) identify consistent predictors of IWL after primary MBS. Methods Following PRISMA guidelines, we searched PubMed, Scopus, and Web of Science for studies reporting IWL after primary MBS. Meta-analyses of pre-, intra-, and postoperative factors were performed using random-effects models. Heterogeneity was assessed using the I² statistic and Cochran's Q test. Results Sixty-five studies (n = 26 804 patients) were included. The pooled IWL rate was 27% (95% c.i.: 23–33%) using %EWL and 20% (95% c.i.: 12–32%) using %TWL, highlighting substantial variation based on definition. Preoperative type 2 diabetes mellitus (T2DM), hypertension, and higher baseline BMI were consistently associated with IWL. Demographic factors such as age, sex, and smoking status showed no significant association. In %TWL-based analyses, RYGB was associated with a significantly lower risk of IWL (RR = 0.71; 95%c.i.: 0.55–0.92), while SG results were more variable and not statistically significant. Conclusion IWL represents a distinct postoperative outcome primarily driven by preoperative metabolic comorbidities rather than demographic characteristics. RYGB appears to confer a protective effect, particularly in metabolically high-risk patients, whereas the role of SG remains less consistent. The absence of a standardized definition for IWL continues to hinder cross-study comparisons. Establishing a unified definition is essential to improve clinical research, risk stratification, and preoperative patient counselling.
Cruz et al. (Thu,) reported a other. Insufficient weight loss occurred in 27% of patients post-bariatric surgery, with RYGB associated with a reduced risk (RR = 0.71) compared to SG, influenced by preoperative comorbidities.