The following review is being published by the American Society for Metabolic and Bariatric Surgery in response to numerous inquiries made to the Society by patients, physicians, society members, hospitals, and others regarding one-anastomosis gastric bypass as a primary treatment for obesity or metabolic disease. The review is based on current clinical knowledge, expert opinion, and published peer-reviewed scientific evidence available at this time. The review is not intended as, and should not be construed as, stating or establishing a local, regional, or national standard of care.

Obesity is associated with a high incidence of obstructive sleep apnoea (OSA). Bariatric surgery is postulated to lead to OSA resolution, but there is inconclusive evidence on its efficacy. We used objective measurements to determine the rate of resolution or improvement of OSA in patients who had bariatric procedures in our unit.

The number of people that are overweight and obese is continuously increasing both in the adult and adolescent populations. Coinciding with this is the increased prevalence of health problems such as type 2 diabetes (T2D). Bariatric surgery is the only proven long-term treatment of obesity and may induce remission of T2D, although the underlying mechanisms are unknown. The translational studies presented here might provide insight on the mechanism of steady-state energy balance of the obese phenotype using a special time-restricted feeding regimen for weight loss during the steady-state energy balance; and mechanism by vagal blocking therapy (vBLoc® therapy) as a new treatment for obesity; and possible mechanism behind the remission of T2D following gastric bypass surgery.

Obesity and physical inactivity are major health problems. Roux-en-Y gastric bypass (RYGB) surgery results in significant weight loss and reduces obesity-related morbidity and mortality. Physical activity lowers the risk of cardiovascular disease and premature death. The aims of this study were to elucidate the effects of RYGB followed by 6 months of supervised physical training on physical capacity. In a randomized controlled trial, 60 participants eligible for RYGB were randomized 6 months post-surgery to either two weekly physical training sessions for 26 weeks (INT) or a control group (CON). Aerobic capacity (VO2 max), muscle strength (MS) of the shoulder and hip and physical function were measured pre-surgery and 6, 12 and 24 months post-surgery. RYGB per se decreased MS in all tested muscle groups, had no effects on VO2 max but improved physical function. After the intervention, INT had a significant 0.33 L min-1 increase in VO2 max compared to CON (95% CI: 0.07-0.57, P = 0.013). Furthermore, MS in the hip adductor increased significantly with 13 N (95% CI: 3.6-22.4, P = 0.007) and a between-group difference was found in the Stair Climb Test (0.46 repetitions [95% CI: 0.02-0.91, P = 0.042]). The effects were not maintained at follow-up. Supervised physical training following RYGB improved VO2 max, hip MS and physical function, but the positive effects were not maintained at follow-up. While activities of daily life may become easier as a result of RYGB, the observed extensive post-operative loss of MS requires more attention to increase the patient's physical capacity prospectively.