Surgical Treatment of Type 2 Diabetes Mellitus in <35 Body Mass Index (BMI)

Inclusion Criteria: * Type 2 diabetes mellitus * Duration of diabetes ≥ 3 years * Poor glycemic control (i.e., HbA1c ≥ 7.5%) in spite of hypoglycemic therapy in accordance with good clinical practice (GCP) Exclusion Criteria: * Specific contraindication to obesity surgery or biliopancreatic diversion or gastric bypass * Pregnancy * Medical conditions requiring acute hospitalisation * Severe diabetes complications or associated medical conditions \[such as blindness, end-stage renal failure (i.e. serum creatinine \>2 mg/dl), liver cirrhosis, malignancy, chronic congestive heart failure (NYHA class III and IV)\] * Recent (within preceding 12 months) myocardial infarction, stroke or TIA * Unstable angina pectoris * Psychological conditions which may hamper patient's cooperation * Geographic inaccessibility * Any condition which, in the judgment of the Investigator, may make risky the participation in the study or bias the results