Short-Term Changes on Body Composition After Sleeve Gastrectomy and One Anastomosis Gastric Bypass

Changes in body composition after different bariatric surgeries have been studied extensively, but most of them have emphasized on Roux-en-Y gastric bypass. Only a few studies have assessed the effects of sleeve gastrectomy (SG). Also, the effect of one anastomosis gastric bypass (OAGB) on body composition is not fully apprehended. Furthermore, there is no agreement on how much fat-free mass (FFM) loss is tolerable in weight loss interventions. Therefore, we decided to assess the reduction in fat mass (FM) and FFM at 1, 3, 6, and 12 months after two types of bariatric surgery in a single center. In the current retrospective cross-sectional study, the patients' hospital records were analyzed. We included patients who had SG or OAGB and a complete 1-year follow-up record. We recorded demographic data as well as weight, body mass index (BMI), FM, and FFM before and at 1, 3, 6, and 12 months after surgery in a predesigned checklist. We analyzed 311 patients (43 males and 268 females) in the SG (N = 192, 61.7%) and OAGB (N = 119, 38.3%) groups. Both the SG and OAGB groups demonstrated a statistically significant reduction in weight, BMI, FM, and FFM indices at 12 months after the intervention (P < .001). Moreover, no statistically significant difference was observed between the SG and OAGB groups regarding the mean of all body composition indices at 3, 6, and 12 months after the intervention. We found that SG and OAGB effectively decreased weight and body composition indices, comprising FM and FFM, with no significant difference between each other.