06/12/2026
You lost 100 pounds... but how much of it was actually fat?
A review highlighted by Massachusetts General Hospital looked at body composition changes during GLP-1 weight loss and found that in some major studies, approximately 25% to 45% of the weight lost came from lean tissue, not just fat.
That doesn't mean medications like Ozempic and Wegovy are a problem. For many patients, they can be incredibly effective and life-changing.
What it does mean is that the number on the scale doesn't tell the whole story.
As a plastic surgeon, I see this all the time. Two patients can weigh exactly the same, yet look dramatically different because of differences in muscle mass, body fat percentage, and body composition.
While losing weight, it's worth paying attention to:
• Protein intake
• Resistance training
• Body composition measurements such as an InBody or DEXA scan
In some cases, losing weight a little more slowly while preserving or even building muscle can create a better overall result than simply chasing the lowest number on the scale.
Muscle supports metabolism, strength, and body shape. That's one reason body composition often tells a much more complete story than weight alone.
Study Reference:
Neeland IJ, Goodpaster BH, et al. Changes in Lean Body Mass With Glucagon-Like Peptide-1-Based Therapies and Mitigation Strategies. Diabetes, Obesity and Metabolism. 2024.