Two DEXA scans eleven months apart: down 24kg total, of which the scan says 6kg was lean. I want to know whether that ratio is bad, normal, or simply what happens.
The question I want answered is what fraction of loss being lean mass is actually normal, because the numbers quoted here range from 10% to 40% and cannot all be right.
Numbers rather than impressions, if you have them.
Short answer first, then the reasoning. The intervention that works is boring and well evidenced: resistance training two to three times a week at a genuine effort, protein at 1.4 to 2.0 g/kg of reference body weight, and not making the deficit larger than the training can support. Cardio does not protect lean mass and in a deep deficit competes with recovery.
PeptideChemSF said:The intervention that works is boring and well evidenced: resistance training two to three times a week at a genuine effort, protein at 1.4 to 2.0…
Agreed on the ranges, with the condition that a single DEXA is not a measurement, it is one draw from a distribution. Hydration status moves the lean compartment by a kilogram or more between scans, so any comparison of scans done at different times of day or different hydration states is noise.
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Shop Reference StandardsMikeFit_NJ said:Two DEXA scans eleven months apart: down 24kg total, of which the scan says 6kg was lean.
Can confirm the pattern MikeFit_NJ describes. 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 protein. Both numbers need a caveat that matters: "lean mass" on a DEXA is not muscle. It includes water, glycogen and the lean fraction of organs, and glycogen alone carries about three grams of water per gram. A large early lean drop is mostly the glycogen and water going, which is why the first scan flatters and the second is the honest one.
Correct me if the detail matters more than I have assumed.
From the other side of the consultation, briefly.
DEXA scan update relevant to lean mass:
Scanned at months 0, 6, and 12. Here are the body comp numbers:
| Baseline | Month 6 | Month 12 | |
|---|---|---|---|
| Total mass | 259 lbs | 239 lbs | 216 lbs |
| Fat mass | 119 lbs | 79 lbs | 51 lbs |
| Lean mass | 157 lbs | 150 lbs | 153 lbs |
| Body fat % | 44% | 30% | 25% |
Lean mass preserved — actually GAINED 1-2 lbs thanks to progressive overload + 1.4g/kg protein. The lean mass discussion needs to include body comp data, not just scale weight.