Insufficient weight loss after bariatric surgery and its predictors: Tehran Obesity Treatment Study (TOTS)

Abstract

Background: This study aimed to determine the factors related to insufficient weight loss (IWL) following bariatric surgery. Methods: The data for 3456 individuals who had bariatric surgery were obtained prospectively. A bioelectrical impedance analyzer was used to measure body composition changes and compare them between the sufficient (SWL) and IWL groups. The generalized estimated equation approach was used to assess changes in fat mass (FM), fat-free mass (FFM), FFM loss/weight loss percentage (FFML/WL%), and excess weight loss percentage (EWL%). Multivariate logistic regression models were used for IWL to establish independent baseline factors. Results: IWL was recorded in 8% of the cases. The data analysis revealed substantial differences in the changes in FM%, FFM%, FFML/WL%, and EWL% between the SWL and IWL groups after six months of follow-up. The IWL group demonstrated a greater FFML/WL% (Ptime before & after 6 months < 0.05). An older age, a higher baseline BMI, diabetes mellitus (DM), non-smoking, and sleeve gastrectomy (SG) were the predictors of IWL. Conclusion: the significant predictors of IWL included older age, a higher baseline BMI, DM, SG, and non-smoking.