Clinical perspective, offered as context rather than as advice. The distinction that resolves most of these threads is between what is true on average and what is true for one person. Both are real; they answer different questions and get quoted as if they were the same one.

Worth separating that from lean-mass preservation, which this thread keeps folding into the same question. They behave differently and the advice does not transfer.

Dr.CardioMD said:

The distinction that resolves most of these threads is between what is true on average and what is true for one person.

Mine went the same way, slower.

Dr.CardioMD said:

The distinction that resolves most of these threads is between what is true on average and what is true for one person.

Coming at Dr.CardioMD’s question from a different direction. 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.

The figures, for anyone assembling their own picture. If you are going to change something, change one thing and give it long enough to express itself. Four weeks is the usual minimum for anything pharmacological on this board, and two weeks of data has told you almost nothing.

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

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?