I'm so tired of the narrative that GLP-1 medications inevitably cause devastating muscle loss and there's nothing you can do about it. Here are my three DEXA scans over 9 months on tirzepatide:
| Metric | Baseline (Jun '25) | 4.5 Months (Oct '25) | 9 Months (Mar '26) |
|---|---|---|---|
| Total Weight | 231 lbs | 207 lbs | 193 lbs |
| Body Fat % | 34.8% | 28.1% | 22.4% |
| Fat Mass | 80.4 lbs | 58.2 lbs | 43.2 lbs |
| Lean Mass | 144.2 lbs | 142.8 lbs | 144.6 lbs |
| Appendicular Lean Mass | 62.8 lbs | 63.1 lbs | 65.4 lbs |
| Bone Mineral | 6.4 lbs | 6.4 lbs | 6.5 lbs |
Read that again: lean mass went from 144.2 to 144.6 lbs while I lost 38 lbs total. Appendicular lean mass (arms + legs — the best proxy for actual skeletal muscle) INCREASED by 2.6 lbs.
My protocol:
- Progressive resistance training 4x/week (PPL + extra leg day)
- Protein: 180-200g/day (1g per lb of GOAL body weight)
- Creatine: 5g/day
- Sleep: 7-8 hours strictly
- Caloric deficit was moderate — roughly 500-700 cal/day, not the extreme deficits some people end up in
M/36, 5'11". I was not a total beginner to lifting but I was detrained — hadn't lifted seriously in about 3 years before starting this.
This is compelling data. The appendicular lean mass increase is particularly noteworthy because ALM is less confounded by water/organ weight changes than total lean mass. A 2.6 lb ALM increase during a 38-lb weight loss is genuinely impressive.
A few caveats for scientific rigor:
- Creatine supplementation can increase intramuscular water retention, which DEXA reads as lean mass. Estimated effect: 2-4 lbs. Were you taking creatine before the baseline scan?
- DEXA has a coefficient of variation of about 1-2% for lean mass measurements, so small changes should be interpreted cautiously.
- That said, even accounting for both of these, you almost certainly maintained your baseline muscle mass, which is itself an excellent outcome during significant weight loss.
Fair points. To address #1: no, I started creatine at the same time I started tirzepatide, so the baseline scan was pre-creatine. That means some of the lean mass "preservation" could be creatine-related water. If we assume 3 lbs of that is intramuscular water, I'd be at 141.6 lbs of "real" lean mass vs. 144.2 baseline — still only a 2.6 lb loss during a 38 lb weight loss, which is exceptional by any standard.
Re: DEXA variability — all three scans were done on the same machine, same facility, same time of day, fasted. I tried to control as many variables as possible.
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Shop Reference StandardsHow did you manage 180-200g protein per day while on a GLP-1? I'm struggling to hit 100g. The appetite suppression makes it really hard to eat enough, and protein is the most satiating macro so it's a double whammy.
It's a genuine challenge. Here's what works for me:
- Protein shake first thing in the morning (40g) — liquid calories are much easier when appetite is suppressed
- Greek yogurt + protein powder as a snack (35g)
- Two meals centered around lean protein (chicken, fish, lean beef) — about 40-50g each
- Casein shake before bed (25g)
Some days I still fall short and land around 150g. But consistency over perfection. I also time my biggest meal about 2 hours after training when appetite is slightly higher.