Different Limb Lengths in Gastric Bypass Surgery (SLIM) - Part 3: Metabolism and Inflammation

Inclusion Criteria: * 2 x 25 patients with morbid obestiy (BMI of 35 kg/m2 or higher) who comply with the regulatory rules for bariatric surgery in Switzerland (SMOB guidelines) and participate in the SLIM Trial * 15 healthy lean controls Exclusion Criteria: * general contraindications to kind of surgery * known or suspected non-compliance * inability to follow the procedures of the study, e.g. due to language problems, psychological disorders etc. of the participant * participation in another interventional study * BMI \> 60 kg/m2 * height \< 145 cm * CL length of \< 180 cm as measured intraoperatively * ASA physical status classification \> III * inflammatory bowel disease * diabetes * intake of corticosteroids, anti-inflammatory/ immunosuppressive drugs potentially altering immune cells * clinical signs of current infection * known anemia (e.g. hemoglobin \< 110g/L for males, \< 100g/L for females) * known neutropenia (e.g. leucocyte count \< 1.5 x 10\^9/L or ANC \< 0.5 x 10\^9/L) * known immunodeficiency, e.g. HIV * known vasculitis, collagenosis * known adrenal insufficiency and/or substitution with glucocorticoids * risky daily alcohol consumption (\> 24g/d for males, \> 12g/d for females) * drug abuse * known liver cirrhosis Child B or C * known uncontrolled congestive heart failure * known uncontrolled malignant disease * currently pregnant or breastfeeding