Body composition changes in adolescents after laparoscopic sleeve gastrectomy

Background Sleeve gastrectomy (SG) is a commonly used bariatric procedure in severely obese adolescents. Weight loss after SG is associated with marked changes in body composition, but factors associated with such changes have not yet been described in adolescents. Objective To identify factors associated with changes in body weight and composition in adolescents 1 year after SG. Setting University Hospital, Tel Hashomer, Israel. Methods Age, sex, weight, height, preoperative body mass index (BMI), and body fat percent measured by bioimpedance were collected in 25 adolescents (16 males, 9 females, age 16.6±1.5 yr) before and 1 year after SG. Obesity-related complications, preoperative weight loss, and physical activity after surgery were also recorded. Repeated-measures analyses of variance and linear mixed model analyses were performed. Results One year after SG, weight decreased by 32%, fat mass by 55%, and fat-free mass by 9% from baseline. Male participants lost significantly more weight than female participants, with larger decreases in fat mass (-65% versus -41%, P<.001) and body fat percent (-48% versus -21%, P<.001). The amount of physical activity at 1-year follow-up was also associated with larger reductions in body fat percent in both genders. Age or baseline BMI, fat mass, and fat-free mass were not associated with changes in BMI or body composition. Conclusion Among obese adolescents 1 year after SG, the only modifiable factor associated with larger decreases in body fat percent was physical activity. Larger studies are needed to formally identify other possible predictors of body composition changes after SG.