Body composition changes during weight reduction with tirzepatide in the SURMOUNT ‐1 study of adults with obesity or overweight
An erratum to this article was published (Diabetes Obes Metab, Nov 2025 ↗)
Authors' conclusion
In participants with obesity or overweight from the SURMOUNT-1 trial, tirzepatide treatment significantly reduced body weight, fat mass and lean mass compared with placebo, while in post hoc analyses, the proportion of body weight lost as fat or lean mass was relatively consistent including in clinically relevant subgroups.
Study context
- Population
- Adults with obesity or overweight from SURMOUNT-1 with baseline and Week 72 DXA; 73% female, mean weight 102.5 kg, BMI 38.0 kg/m²of 2539 in SURMOUNT-1
- Participants
- 160 adults
- Comparison
- Tirzepatide vs placebo
- Tirzepatiden = 124
- Placebon = 36reference
- Primary endpoint
- Changes in body composition (DXA)
- Follow-up
- Week 72
Methodological detailspost hoc subgroup analyses
- Post hoc subgroup analyses
Primary result
As reported in the abstract
Change in body weight, fat mass and lean mass from baseline
| Group | Value | Fat mass change | Lean mass change |
|---|---|---|---|
| Tirzepatide | −21.3% | −33.9% | −10.9% |
| Placebo | −5.3% | −8.2% | −2.6% |
Value
Tirzepatide−21.3%
Placebo−5.3%
Fat mass change
Tirzepatide−33.9%
Placebo−8.2%
Lean mass change
Tirzepatide−10.9%
Placebo−2.6%
- Tirzepatide vs Placebo: P < 0.001 for all comparisons — body weight, fat mass and lean mass
Further findings
Proportion of weight lost as fat vs lean mass
- Fat mass share of weight lost, both tirzepatide and placebo
- ≈75%
- Lean mass share of weight lost, both tirzepatide and placebo
- 25%
- Proportions consistent across most subgroup analyses (post hoc)
Original publication
Body composition changes during weight reduction with tirzepatide in the SURMOUNT ‐1 study of adults with obesity or overweight. Diabetes Obes Metab. Published 25 February 2025. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →