This is a randomized, open, controlled and single-site clinical trail to investigate the effect and safety of Benaglutide or Metformin in patients with simple obesity who have inadequate weight control.

This is a randomized, open, controlled and single-site clinical trail to investigate the effect and safety of Benaglutide or Metformin in patients with simple obesity who have inadequate weight control.

Screening will be made to select eligible participants before intervention. Patients were randomly assigned to one of two groups(metformin or benaglutide) for therapies for 12 weeks including a two-week dose adjustment period and a 10-week dose stabilization period. Lifestyle interventions will be maintained during the treatment period. Subjects are followed up every 4 weeks for examinations.At the end of the study, data will be collected and analyzed.

Inclusion Criteria:

(1)20 years old≤70 years old; (2) simple obesity, gender is not limited; (3) 28.0≤BMI≤37.5kg/m2; (4) Before the screening period, the body weight was controlled by lifestyle interventions (diet and exercise) for at least 3 months, and weight was decreased by <5% from baseline; (5) Agree to sign the informed consent form;

Exclusion Criteria:

1. Accurately diagnosed as having type 1 or type 2 diabetes according to the WHO 1999 diagnostic criteria;
2. Use weight loss drugs within 3 months before screening;
3. Metformin was used within the first 3 months of screening;
4. Malignant tumors (excluding basal cell or squamous cell carcinoma treated) within 5 years before enrollment
5. Alanine aminotransferase or aspartate aminotransferase > 3 times the upper limit of normal or total serum bilirubin (TB) >34.2 μmol/L (>2 mg/dL)
6. Patients with moderate/severe renal impairment or end-stage renal disease (eGFR < 60 mL/min/1.73 m2); male subjects with serum creatinine (Cr) ≥133 μmol/L (≥1.50 mg/dL Serum Cr in female subjects was ≥124 μmol/L (>1.40 mg/dL);
7. Severe heart, lung, nervous, mental and infectious diseases;
8. Pregnancy, lactation and recent pregnancy plans;
9. Alternate or chronic systemic corticosteroid therapy, defined as treatment with any dose of systemic corticosteroids within 3 months of enrollment visit V1 > 4 weeks
10. History of alcohol abuse, history of abuse of active drugs (opioids, analgesics, etc.) within 6 months before enrollment;
11. Give any other test drug within 30 days before enrollment or within 5 half-lives of other test drugs;
12. Patients with past history or family history of medullitary thyroid cancer (MTC) and patients with type 2 multiple endocrine tumor syndrome (MEN2);
13. Inability to tolerate benalutide, metformin;
14. Any influence of the investigator's judgment on enrollment.