Dr.EndoIndy said:Dr.RenalNash said: ...the muscle loss concern with lean mass...
Muscle fiber type changes during GLP-1-mediated weight loss, relevant to lean mass: preliminary biopsy data suggests that weight loss shifts the skeletal muscle fiber type distribution:
- Decreased Type IIx (glycolytic, fast-twitch) fibers
- Increased Type I (oxidative, slow-twitch) fibers
- Improved mitochondrial density and function
- Enhanced insulin-stimulated glucose uptake per fiber
This "metabolic remodeling" of muscle may contribute to improved insulin sensitivity independent of total lean mass changes. The muscle you keep becomes metabolically better, even if there's less of it[1].
[1] Pirkmajer S, et al. Front Physiol. 2023;14:1123456.
LarryQC_SD said:Agreed on the ranges, with the condition that a single DEXA is not a measurement, it is one draw from a distribution.
That reframing is the part I needed.
Dr.EndoIndy said:Dr.RenalNash said: ...the muscle loss concern with lean mass...
OMG yes. lean mass + resistance training is the combo. Can confirm.
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Browse GL Biochemmia_MS2 said:I lifted three times a week throughout and still lost lean mass.
Body composition tracking via bioimpedance on lean mass (InBody scan every 3 months):
| Metric | Baseline | Month 3 | Month 6 | Month 9 |
|---|---|---|---|---|
| Skeletal Muscle (lbs) | 74 | 72 | 68 | 72 |
| Body Fat (lbs) | 91 | 76 | 54 | 46 |
| Body Fat % | 40% | 32% | 27% | 22% |
| Visceral Fat (cm²) | 171 | 116 | 91 | 61 |
Note: skeletal muscle mass dipped initially then recovered with consistent resistance training + high protein. The visceral fat reduction is where the metabolic magic happens.