Writing this once so I can stop repeating it across threads. It is about lean-mass preservation, and it is deliberately narrow — everything I am not confident about is marked as such.
What is actually established
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.
The condition it depends on
Protein targets should be set on a reference weight rather than current weight. Setting 1.6 g/kg on a starting weight of 130kg produces a target nobody hits on a suppressed appetite.
The practical version
If you are tracking this properly: same scanner, same time of day, same hydration, at least six months apart, and read grip strength or a lift number alongside it. Function is the outcome; the scan is the proxy.
What I am not sure about
The bit I cannot resolve on my own 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.
dave_SLC 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…
Agreeing with dave_SLC, and the qualification matters more than the agreement. 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.
dave_SLC 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…
This is where I part company with the consensus forming above. I think this board over-worries about lean mass. Some lean loss is obligatory — you need less muscle to move a smaller body, and preserving mass you no longer need is not a health outcome. The question is whether strength and function held, and mine did.
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View ResultsTaking the question as asked, rather than the general version of it. There is also a quality change that the scan cannot see. Weight loss shifts fiber-type distribution toward Type I and improves mitochondrial density and insulin-stimulated glucose uptake per fiber — so the muscle you keep is metabolically better even though there is less of it. That does not make the loss irrelevant, but it explains why function often holds up better than the number suggests.
Dr.SleepRoch 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…
True, though the ladder is longer and that is not a neutral detail — six dose steps means six opportunities to stall on the way up, and plenty of people never reach the dose the headline number came from.