Differences in Body Composition in Patients with Obesity 1 Year After Roux-En-Y Gastric Bypass: Successful Vs. Unsuccessful Weight Loss

The aim of this study is to compare the differences in body composition in patients with obesity with successful weight loss (SWL) and unsuccessful (USWL) 1 year after Roux-en-Y gastric bypass (RYGB). We included 36 women and 22 men. After stratifying patients according with SWL (defined as >= 50% of excess weight loss), fat-free mass (FFM) and fat mass (FM) trajectories were analyzed in each group. The %FM in SWL women (78%) was lower than USWL (36 vs. 44, p < 0.001). The %FM in SWL men (77%) was lower than USWL (27 vs. 38, p < 0.05). A lower %FM before surgery increased the probability of success (p < 0.05). SWL patients have a lower %FM, and those with lower pre-surgical %FM are more likely to have SWL 1 year after RYGB.