I've been getting quarterly DEXA scans since starting tirzepatide 14 months ago and I promised this forum I'd share my complete data once I had a meaningful dataset. Here it is.

Background: Male, 42, started at 118kg. On tirzepatide 12.5mg. Resistance training 4x/week (upper/lower split) since month 2. Protein intake 1.5-1.7g/kg throughout. Creatine 5g/day since month 3.

DEXA Scan Results:

Key Takeaways:

• Total weight lost: 33.1kg
• Fat lost: 26.9kg (81.3% of total loss)
• Lean mass lost: 6.2kg (18.7% of total loss)
• The STEP/SURMOUNT trials showed ~35-40% lean mass loss without structured exercise. I'm at 18.7%.
• Lean mass loss was front-loaded — most occurred in months 0-6 before my training program matured. Months 9-14 showed only 0.6kg lean loss despite continued weight loss.

The data speaks for itself. Lifting works. It's not optional if you care about your body composition, metabolic health, and long-term outcomes.

this is genuinely impressive data and mirrors what we see in the clinical literature. A few comments:

Your lean mass preservation ratio of ~81% fat loss is significantly better than the trial averages. The combination of resistance training + adequate protein + creatine is doing exactly what the evidence predicts.

The observation about front-loaded lean mass loss is particularly interesting. The first 3-6 months of rapid weight loss is when muscle loss risk is highest because:

1. The caloric deficit is often most severe (appetite suppression peaks)
2. Training programs haven't matured enough to provide adequate stimulus
3. People are still figuring out their protein intake

This argues for starting resistance training AND optimizing protein from day one of GLP-1 therapy, not waiting until you've already lost lean tissue.

Lean mass lost: 6.2kg (18.7% of total loss)

Important note: some lean mass loss is unavoidable and even expected with significant weight loss. Your body requires less structural lean mass to support a lighter frame. The goal isn't zero lean mass loss — it's minimizing it and preserving functional strength. Your strength numbers going up while bodyweight drops tells the real story.

Okay this is making me nervous. I'm 7 months in, lost 22kg, no resistance training. Just walking and the medication. Am I screwed? Is all my muscle gone?

I can't afford DEXA scans and I've never set foot in a gym. Be honest with me — how bad is the damage?

First — breathe. You are NOT screwed. Muscle isn't gone forever; it has "muscle memory" (via myonuclei) and can be rebuilt. Starting resistance training now, even 7 months in, will absolutely help.

Without exercise, your lean mass loss is likely in the 30-40% range of total weight lost — so maybe 7-9kg of lean out of your 22kg. Not ideal, but not catastrophic.

What you can do RIGHT NOW:

• Start resistance training, even bodyweight exercises at home. Push-ups (wall or knee), squats, lunges, planks.
• Prioritize protein — aim for 1.2-1.4g/kg minimum
• You don't need a gym. Resistance bands cost £15 and you can do a full program at home.

It's never too late to start. The best time was 7 months ago. The second best time is now.

The advice above is right. And for what it's worth — look at my data. I didn't start lifting until month 2, and my training wasn't dialed in until maybe month 4-5. Most of my lean mass loss happened before I got serious about lifting. But the curve flattened dramatically once I did.

You can absolutely change your trajectory starting today. And you don't need DEXA to track progress — grip strength (cheap dynamometer on Amazon), how many bodyweight squats you can do, how long you can plank. Functional measures tell you a lot.