Outcomes of Surgical and Nonsurgical Treatments in Adults With Metabolic Conditions and a BMI of 30.0 to 34.9 kg/m2

Outcomes (at 1 year unless otherwise specified)Bariatric Surgery*Behavioral Changes**Medications**
  • A BMI decrease of 5 to 7 kg/m2 (about 15 to 20 kg for someone whose height is 5 ft 6 in).
  • Weight gain from 1 to 5 kg with some drugs.
  • Weight loss of 2.8 kg with GLP-1R agonists.
  • No weight change with metformin.
HbA1c, percentage of total hemoglobin
  • Decrease of 2.6 to 3.7 percentage points.
  • Decrease of 0.3 to 2.2 percentage points.
  • Decrease of 0.5 to 1.0 percentage points.
Other metabolic outcomes
  • Diet improved fasting glucose (a reduction of 1.3–36.6%) and triglycerides (a reduction of 11.3–58.9%).
  • The PREDIMED study conducted in Spain found that a Mediterranean diet reduced metabolic syndrome prevalence by 13.7 percent at 1 year.
  • The Finnish Diabetes Prevention Study found that behavioral change reduced metabolic syndrome prevalence at 3.9 years (OR = 0.62).
  • Most medications had minimal effects on systolic and diastolic blood pressures with changes less than 5 mmHg.
  • Metformin and second-generation sulfonylureas generally decreased LDL-cholesterol levels.
Prevention of diabetes
  • Data unavailable.
  • The U.S. Diabetes Prevention Program (DPP) found diabetes incidence at 10 years reduced by 34 percent by behavioral change versus placebo.
  • The DPP found diabetes incidence at 10 years reduced by 18 percent in the metformin group versus placebo.

Data are primarily from observational studies and a few RCTs.


Data are almost entirely from systematic reviews and RCTs.

Oral medications include second-generation sulfonylureas, biguanides, thiazolidinediones, meglitinides, and alpha-glucosidase inhibitors.

Abbreviations: GLP-1R = glucagon-like peptide 1 receptor; LDL = low-density lipoprotein; OR = odds ratio; RCT = randomized controlled trial

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