This research is aimed at verifying the effects of diets with high protein and low glycemic index (GI) on weight management among overweight or obese Chinese adult. Additionally, the investigators intend to verify the effects of two new approaches, including food replacement and Internet-of-things (IOT) monitoring on weight control.

Inclusion Criteria:

• Health adult, age:18-65，BMI（kg/m2）:27.0-40.0

Exclusion Criteria:

• Patients under regular medical treatment for chronic diseases like diabetes, hypertension, gout and hyperuricemia.
• The patients with chronic renal diseases or other diseases which impose restrictions on the intake of proteins.
• Mental patients.
• People who suffer from secondary obesity caused by endocrine, metabolic disorders or some central nervous system diseases.
• People who are under medical or surgical weight-loss treatments in the past three months.
• People whose weight fluctuations are not less than 5kg in the past two months；
• People with food allergies.
• Men or women who drink regularly over 25g or 15 g daily,respectively.
• Pregnant women and women who prepare to be pregnant.
• Lactating women