1) weight loss/metabolic surgery may be considered in Asian populations with T2DM with or without comorbidities; 2) weight loss/gastrointestinal metabolic surgery should be a treatment option in Asian populations with BMI 30-35 kg/m2 and T2DM, especially with cardiovascular risk factors, when lifestyle and medications are difficult to control blood glucose or comorbidities; 3) weight loss/gastrointestinal metabolic surgery should be a treatment option in Asian populations with BMI 28.0-29.9 kg/m2 with T2DM and at least 2 additional criteria for metabolic syndrome. 29.9 kg/m2 in an Asian population with combined T2DM and centripetal obesity (waist circumference ≥ 90 cm in men and ≥ 80 cm in women) and at least 2 additional criteria for the conditional metabolic syndrome: high triglycerides, low HDL cholesterol levels, and high blood pressure. 4) For adolescents with BMI ≥ 40 kg/m2 or ≥ 35 kg/m2 with severe comorbidities, and who are ≥ 15 years of age, skeletally mature, and in Tanner developmental class 4 or 5, LAGB or RYGB may also be considered as a treatment option with the patient’s informed consent; 5) For T2DM patients with a BMI of 25.0-27.9 kg/m2 , surgery should be performed with informed consent, strictly according to the study protocol. However, the nature of these procedures should be considered purely as part of an experimental study approved in advance by the ethics committee and should not be extensively expanded. All patients with type 2 diabetes mellitus who have experienced poor results or are intolerant to long-term non-surgical treatment may be considered for gastrointestinal surgery as long as there are no obvious contraindications to surgery. Better outcomes can be expected if the following conditions are met: (1) the patient is ≤65 years old; (2) the patient has had T2DM for ≤15 years; (3) the fasting C-peptide is more than 1/2 of the lower limit of normal and the C-peptide is more than twice as responsive 2 hours after meals compared to before meals. At the same time, patients do not have serious mental disorders or intellectual disabilities; patients fully understand the surgical modality for treating diabetes, understand and are willing to take the risk of potential complications of the surgery, understand the importance of postoperative diet and lifestyle changes and are willing to bear them; patients can actively cooperate with postoperative follow-up and other aspects are also considered in the selection of surgery.