Rationale: Bariatric surgery (BS) induces sustained loss of body fat mass (FM) with an inevitable loss of lean mass (LM). In contrast, menopause leads to deleterious changes in body composition (BC) related to estrogen deficiency including LM loss and increases in total and visceral adipose tissue (VAT). This study aims to assess BC in post-menopausal women after RYGB (Roux-en-Y gastric bypass) and compares their profile with age and BMI matched controls. Methods: Cross-sectional case-control study of 41 post-menopausal women aged ≥50 years who underwent RYGB at least 2 yrs prior to the study. Control population consists of 41 age and BMI-matched post-menopausal women. 2/41 BS patients and 8/41 controls were on hormone replacement therapy. Both groups had a DEXA scan to evaluate BC and a blood test to assess lipids and glucose metabolism markers. Results: Mean age was 58.4[SD=6.2] vs 59.4[SD=3.2] yrs (p=0.4) and mean BMI was 29.6[SD=4.9] vs 31.1[SD=5.6] kg/m2 (p=0.2) in BS patients vs controls, respectively. RYGB was performed a median of 90 months prior to DEXA. Total weight loss was 28.5%[SD=10] and excess weight loss was 67.5%[SD=29.2]. Compared controls, BS patients showed higher LM percentage (57.7%[SD=8%] vs 52.5%[SD=5%], p=0.001) and reduced FM (39.4%[SD=8.4%] vs 45.9%[SD=5.4%] p<0.01) associated with lower VAT (750.6[SD=496] vs 1295.3[SD=688] gr, p<0.01), and android fat (44.6%[SD=7.5%] vs 48.21%[SD=4.9%]). Post-BS women showed a better lipid profile compared to controls (total cholesterol 4.8[SD=0.9] vs 5.5[SD=0.94] mmol/l, p<0.001; LDL 2.4[SD=0.8] vs 3.4[SD=0.8] mmol/l p<0.001; HDL 1.9[SD=0.4] vs 1.6[SD=0.4] mmol/l p=0.008). Glucose markers were not different. Conclusion: Post-menopausal women after RYGB have a decreased FM and VAT with a greater LM and a better lipid profile compared to controls. Weight loss after RYGB seems to sustain long-term impact on metabolic health. Disclosure of Interest: None declared.