Continuous Glucose Monitoring (CGM) After Surgical Variations of the Roux-en-y Gastric Bypass

Inclusion Criteria: 1. Patients who underwent bariatric-metabolic surgery at the Medical University of Vienna in the years 2012-2016 for the "long and narrow" pouch group 2. Patients who underwent bariatric-metabolic surgery at the Clinic of Hollabrunn in the years 2010- 2012 for the "short and wide" pouch group 3. Patients on oral medication for diabetes mellitus (for subgroup assessment) 4. Stable weight (not more than + 15kg from lowest weight postoperatively) 5. Stable BMI Exclusion Criteria: 1. Unable to give written informed consent 2. Patients with methods other than RYGB 3. Reoperation within the observed period 4. Any intervention changing pouch size or diameter of the anastomosis after the initial operation 5. Known allergy to oral contrast agent 6. Any regular intake of medication interfering with blood glucose levels