AI Generated Image
What Really Disappears When You Lose Weight on GLP-1 Drugs?
SciTechDaily • • health
Key Points:
- New research presented at the European Congress on Obesity (ECO2026) found that 80-85% of weight lost with GLP-1 obesity drugs, including semaglutide, liraglutide, and tirzepatide, comes from fat, while relative skeletal muscle mass is largely preserved.
- The study analyzed 486 adults with obesity using bioelectrical impedance analysis (BIA) to separately track fat and muscle changes during treatment periods up to over 24 months.
- After about 14 months, patients lost an average of 9.9% of body weight, with fat mass decreasing by 18% and skeletal muscle mass only by 5%, indicating favorable body composition changes rather than muscle wasting.
- Statistical modeling showed that skeletal muscle mass remained stable over time when accounting for fat mass changes, and more than 70% of patients preserved or increased their relative muscle mass.
- Researchers note limitations due to the retrospective design, missing data, lack of placebo control, and predominance of female participants, emphasizing the need for larger prospective trials to assess long-term effects.
