Back in January, I wrote about GLP-1 medications. What they are, the pros and cons, and what to think about before coming off them. If you missed it, worth a read.
But since then, new research has come out that I can’t ignore. And honestly, it changes the conversation a little.
Here’s the part nobody’s talking about enough.
The Scale Wins. Your Muscles Might Not.
GLP-1 medications like Ozempic and Mounjaro are doing what they’re supposed to do. People are losing weight. Real weight. And that’s not nothing.
But here’s what the latest clinical data is showing: a significant chunk of that weight isn’t fat. It’s muscle.
In the STEP 1 trial using semaglutide, participants lost an average of 33 pounds. Nearly 45% of that came from lean mass. That means close to half of what people lost wasn’t the stuff they were hoping to lose.
Tirzepatide (Mounjaro) showed better fat-to-muscle ratios overall, but a 2026 study found users still lost 2% more lean body mass compared to semaglutide users by the 12-month mark.
To be clear: this is not a slam on the medications. Losing weight through any means involves some lean mass loss. That’s normal physiology. The concern is when nobody tells you it’s happening, and you have no plan to address it.
Why Muscle Loss Actually Matters for the Long Game
Muscle isn’t just for the gym crowd. It’s your metabolism’s engine.
Less muscle means your body burns fewer calories at rest. Which makes maintaining weight loss harder. Which is exactly why so many people struggle after stopping GLP-1s and sometimes even while still on them.
The medication can suppress your appetite and help with the food noise. It cannot build your muscle. That part is still your job.
What You Can Do About It Right Now
- Strength train at least 3 times per week. This is the most direct way to preserve and build lean muscle while losing weight. Not optional. Non-negotiable.
- Prioritize protein at every meal. Aim for 0.7 to 1 gram per pound of bodyweight daily. Protein gives your body the raw material to hold onto muscle when calories are reduced.
- Don’t skip meals to speed things up. Extreme calorie restriction makes muscle loss worse, not better. Slow and steady still wins this race.
- Track more than the scale. If you can, monitor body composition, not just weight. Losing 10 pounds is great. Losing 10 pounds of fat while keeping your muscle is the actual goal.
Whether you’re on a GLP-1 or not, these habits matter. The medication changes the equation. It doesn’t change the fundamentals.
If you want help putting a real plan together around this, that’s exactly what we do. Reach out and let’s talk.
Michael Wilkie
Aspire Health & Fitness