There will be a randomized clinical trial, non-blind, 3-arm treatment (medical, surgical, gastric bypass and ileal transposition surgery with and sleeve), which will be conducted in a single center - S.B.S. Hospital Sirio Libanês, including 75 research subjects with type 2 diabetes mellitus and obesity class I. In order to compare the effect of weight loss on glycemic control among medical and surgical groups, and after 2 years of follow up, the results of efficacy, safety and maintenance will be compared between the three groups.

Inclusion Criteria:

• Man or woman with Type 2 diabetes mellitus (DM) aged between 25 and 65 years, with time since diagnosis of diabetes less than 10 years.
• Grade I obesity (BMI between 30-35)
• Inadequate glycemic control with HbA1c between 7.0 to 9.5% at baseline, in the presence of drug treatment for diabetes in the last year.
• Reserve pancreatic C-peptide> 1.0 at baseline.
• Overweight stable defined as BMI> 30 in the last two years.

Exclusion Criteria:

• History ketoacidosis, diabetes mellitus type 1, diabetes followed by pancreatitis.
• Repetition of measurements (ie, 2 or more within 1 week) fasting plasma glucose(FPG) > 240 mg / dL during the pre-treatment.
• History of Severe Proliferative Diabetic Retinopathy.
• Autonomic neuropathy.
• Loss or gain significant weight within the last 12 weeks (range, 5% body weight)
• Renal insufficiency
• History of renal disease treated with immunosuppressive therapy, history of dialysis or kidney transplantation.
• Presence of other renal diseases (eg nephrotic syndrome, glomerulonephritis)
• Acute myocardial infarction, unstable angina (NYHA class III-IV), revascularization or stroke within the previous 3 months of the initial visit.
• Uncontrolled hypertension defined as diastolic blood pressure> 100mm/Hg and diastolic blood pressure> 160mm/Hg at the initial visit.
• History of Hepatitis B or Hepatitis C.
• Criteria for Hepatic insufficiency defined as Child B and C liver disease clinically active and aspartate aminotransferase (AST) and alanine aminotransferase (ALT) above 3 times the upper limit of normal.
• History of prior bariatric surgery.
• Inflammatory Bowel Disease.
• History neoplasm within the last 5 years (except for squamous cell carcinoma and basal skin and cervical carcinoma in situ)
• Clinically important hematologic disorder (symptomatic anemia, bone marrow proliferative disorders, thrombocytopenia, ..)
• History antibody positive human immunodeficiency virus (HIV)
• Surgery with general anesthesia within 12 weeks prior to the initial visit or incomplete recovery from prior surgery.
• History of drug or alcohol abuse within 3 years before the initial visit.
• Pregnancy or breastfeeding or planning pregnancy in the next two years.