The investigators would like to conduct a randomized clinical trial to compare the efficacy of diabetes treatment between different gastric bypass procedures involving type 2 diabetics patients with BMI from 27.5 to 35 kg/m2

The investigators would like to conduct a randomized clinical trial to compare the efficacy of diabetes treatment between different gastric bypass procedures involving type 2 diabetics patients with BMI from 27.5 to 35 kg/m2. This program will determine the relative effectiveness among LMGB 、RYGB and SADJB .The primary end point including HbA1C<6.0%, LDL-C<100mg/dl and SBP<130mmHg at one year after surgery. Through this study, the investigators may understand which gastric bypass is the best for type 2 diabetic's treatment. The investigators also hope some new treatment modulation may be developed.

Inclusion Criteria:

• Age 20 to 67 years
• Diagnosed with T2DM at least 6 months prior to enrollment, under the active care of a doctor for at least the six months prior to enrollment, HbA1c ≥ 7.5 %
• Body Mass Index (BMI) ≥ 27.5 kg/m 2 and ≤ 34.9 kg/m 2
• Willingness to accept random assignment to either treatment group.
• Willingness to comply with the follow-up protocol
• Written informed consent.

Exclusion Criteria:

• Cardiovascular event (myocardial infarction, acute coronary syndrome, coronary artery angioplasty or bypass, stroke) in the past six months.
• Current evidence of congestive heart failure, angina pectoris, or symptomatic peripheral vascular disease.
• Cardiac stress test indicating that surgery would not be safe.
• Pulmonary embolus or thrombophlebitis in the past six months
• Cancer of any kind (except basal cell skin cancer or cancer in situ) unless documented to be disease-free for five years
• Serum creatinine ≥ 1.5 mg/dl
• History of stomach surgery, bile duct surgery, pancreatic surgery, splenectomy, or colon resection
• Previous organ transplantation.
• History of alcohol or drug dependency
• Current participation in a conflicting research protocol.