Adding the clinical framing, because it changes how the question reads.

Physical therapist weighing in on lean mass. I work with bariatric and metabolic patients daily.

The resistance training evidence is critical here:

The Lundgren 2024 JAMA paper[1] showed that structured resistance training preserved 73% more lean mass in GLP-1 patients vs medication alone. When discussing lean mass, we MUST include the exercise component.

My minimum prescription: 3x/week compound movements (squat, deadlift, press, row), progressive overload, 7-10K steps/day, and 1.2-1.6g protein/kg/day.

DoseLogDan said:

Back pain as a lean mass side effect: not from the medication itself, but from rapid body composition changes.

Saving this. It is the first explanation that did not require me to already understand it. I will report back once I have actually tried it.

Clinical perspective, offered as context rather than as advice.

My endo's protocol for lean mass plateau: if weight loss stalls for 6+ weeks at current dose, we go through this checklist before titrating up:

1. Food diary review — is intake creeping up?
2. Protein check — minimum 100g/day
3. Activity audit — steps + resistance training
4. Sleep quality — poor sleep kills GLP-1 efficacy
5. Stress/cortisol management

Only after addressing all of these do we increase the dose. Often fixing one lifestyle factor restarts progress without needing more medication.

james_edin said:

My endo's protocol for lean mass plateau: if weight loss stalls for 6+ weeks at current dose, we go through this checklist before titrating up: Food…

This is my experience too, for whatever a second data point is worth. Posting only so the count is not one.

Moderator note: leaving this open. It is being argued well and the disagreement is the useful part.