This study aims to analyze the pre- and post-operative clinical, hormonal and biochemical changes in moderately obese type 2 diabetic patients who are sub-optimally controlled on at least 2 anti-diabetic agents. Study participants will either receive implantation of the gastric contraction modulator or conventional treatment with insulin therapy.

Inclusion Criteria:

• Able to provide written informed consent
• Adult patients aged between 18 and 60 years (inclusive)
• Male or female of Chinese ethnicity
• Type 2 diabetes mellitus with disease duration of greater than 2 and less than 10 years
• severe obesity, includes BMI 25 to 27.5 kg/m and central obesity defined by waist circumference greater than 90 cm in women and greater than 95 in men, or BMI greater than 27.5 to less than 35 kg/m
• HbA1c greater than or equals to 7.5% but less than 10% despite treated with maximum dose or maximally tolerated dose of 2 anti-diabetic drugs (OAD) with good drug compliance

Exclusion Criteria:

• On anti-obesity drugs
• On insulin treatment at the time of the recruitment
• On glitazone or incretins (dipeptidyl peptidase-4 inhibitor or glucagons-like peptide-1) treatment
• On any implantable device including cardiac pacing
• Anticipated to have MRI examinations
• Fasting C-peptide level less than 0.5g/L
• Renal impairment (defined as serum creatinine greater than 150mol/L and/or estimated glomerular filtration rate less than 60 mL/min/1.73m)
• Significant liver impairment (ALT more than 3 times upper limit of normal range)
• Active malignant disease. Patients with malignant disease who have been disease-free for at least 5 years are eligible
• Active infection
• Active and uncontrolled thyroid diseases
• Childbearing age female patients without reliable contraceptive methods
• Life expectancy less than 12 months
• Administration of another investigational drugs or procedures within 4 weeks before screening
• Any medical illness or condition as judged by the investigators as ineligible to participate the study
• Special population, e.g. prisoner, mentally disabled, investigators' student or employees