The purpose of this study is to compare the outcome in a broad perspective after laparoscopic Roux-en-Y gastric bypass and laparoscopic BPD-duodenal switch in the treatment of superobesity (body mass index [BMI] > 50 kg/m2).

Surgery is the only treatment of morbid obesity that has proven to result in efficient and long lasting weight loss. There are few studies comparing different surgical techniques, especially in a randomized setting.

Superobesity (BMI > 50 kg/m2) demands an efficient surgical approach to result in satisfying weight loss. Laparoscopic techniques have been established to perform Roux-en-Y Gastric bypass and Biliopancreatic Diversion with Duodenal Switch which both are good options for treating superobesity.

This study aims to compare the outcome after surgery in a broad perspective (weight loss, metabolic normalization, gastro-intestinal side effects, eating patterns, body composition, health economics). Patients will be randomized to either surgical procedure and will be followed for five years.

Inclusion Criteria:

• BMI 50-60 kg/m2

Exclusion Criteria:

• Prior obesity operation
• Prior major abdominal surgical procedure
• Severe disabling cardiopulmonary disease
• Malignancy
• Oral steroid treatment
• Condition associated with poor compliance