Bariatric surgery is currently the only evidence-based treatment for severe obesity in adults. Recent data also support the use of bariatric surgery in selected adolescents suffering from severe obesity who do not show successful weight reduction and remission of comorbidities in the multimodal lifestyle programs.

A study from the USA showed significant improvement of the obesity related comorbidities and quality of life after Sleeve Gastrectomy (SG) and Roux-en-Y Gastric Bypass (RYGB) in adolescents after a three-year follow-up. A study from Sweden demonstrated that weight loss and improvement in metabolic health and quality of life following RYGB appears at least as beneficial in adolescents as in adults over a five year follow-up. Thus, bariatric surgery is currently an established treatment for selected adolescents, which is about to be introduced in the Netherlands.

To date, the RYGB and SG are the dominating surgical techniques and are routinely used in adults as well as adolescent bariatric surgery internationally. There is a strong international trend within adolescent bariatric surgery toward the increasing use of SG over RYGB, yet data is largely lacking to support the potential use of SG. The overall aim of this trial is to obtain level one evidence regarding differences in clinical outcomes between RYGB and SG in a multicenter randomized clinical trial. By assessing safety and efficacy we aim to provide guidance regarding surgical procedure choice based on reliable risk-benefit data, overall as well as in subgroups.