GenomicsKate said:The honest range is roughly 20 to 40% of total loss as lean mass without deliberate resistance training, and roughly 10 to 20% with it plus adequate…
Thank you — that is the clearest version of this I have read, and I have read a lot of them. Printing the relevant bit and taking it with me.
From the other side of the consultation, briefly.
Bone density monitoring on lean mass: DEXA bone density at baseline and month 12.
Lumbar spine T-score: -0.12 → -0.7 (stable to slightly improved)
Femoral neck T-score: -0.12 → -0.8 (stable)
No significant bone loss despite 59 lbs of weight loss. Key factors: adequate calcium (1200mg/day), vitamin D (5000 IU/day), resistance training 3x/week, and adequate protein. Weight-bearing exercise is critical for maintaining bone density during rapid weight loss.
LibrarianMeg said:Regarding lean mass: I accidentally injected my dose intramuscularly instead of subcutaneously last week (went in at wrong angle, too deep).
Sharing my comprehensive lab data relevant to lean mass:
| Biomarker | Baseline | Month 3 | Month 6 | Month 9 |
|---|---|---|---|---|
| Weight (lbs) | 279 | 239 | 219 | 214 |
| A1C (%) | 7.4 | 6.9 | 6.0 | 5.6 |
| hsCRP (mg/L) | 9.0 | 3.0 | 2.5 | 1.5 |
| Triglycerides | 189 | 159 | 139 | 99 |
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.
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Browse GL BiochemDr.GastroMayo said:There is also a quality change that the scan cannot see.
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.
[1] Lundgren JR, et al. JAMA. 2024;331(1):38-48.
Moderator note: leaving this open. It is being argued well and the disagreement is the useful part.