From the other side of the consultation, briefly.

Sharing my comprehensive lab data relevant to lean mass:

Protocol: Tirzepatide 15mg/wk, resistance training 4x/week, protein 1.6g/kg/day.

The improvements in lean mass are clearly reflected in these numbers. The inflammatory marker reduction (hsCRP) is particularly striking.

A narrower follow-up, since the general answer is now clear:

How would you tell the difference between that and the alternative explanation?

Dr.GastroMayo said:

Sharing my comprehensive lab data relevant to lean mass: Biomarker Baseline Month 3 Month 6 Month 9 Weight (lbs) 263 243 213 203 A1C (%) 6.8 6.3 6.0…

Back pain as a lean mass side effect: not from the medication itself, but from rapid body composition changes. Losing 44 lbs shifts your center of gravity and your core muscles need time to adjust.

Physical therapy has been essential. Core strengthening exercises (planks, dead bugs, bird dogs) daily for 10 minutes have eliminated my lower back pain. Your body is literally relearning how to carry itself.

Dr.GastroMayo said:

Sharing my comprehensive lab data relevant to lean mass: Biomarker Baseline Month 3 Month 6 Month 9 Weight (lbs) 263 243 213 203 A1C (%) 6.8 6.3 6.0…

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.

Moderator note: good thread. Keeping it here rather than moving it, because the question is general enough to be useful. No action needed from anybody.