TrialNerd_Beth 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.

hans_munich said:

I lifted three times a week throughout and still lost lean mass.

OMG yes. lean mass + resistance training is the combo. Can confirm.

Dr.RaviCardio said:

I think this board over-worries about lean mass.

Back pain as a lean mass side effect: not from the medication itself, but from rapid body composition changes. Losing 53 lbs shifts your center of gravity and your core muscles need time to adjust.

Physical therapy has been essential. Core strengthening exercises (planks, dead bugs, bird dogs) daily for 10 minutes have eliminated my lower back pain. Your body is literally relearning how to carry itself.

One thing that is still open after AttorneyGrant’s answer:

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?

Reporting back.

Follow-up: I dropped the cardio to two easy sessions and put the effort into three real lifting sessions. The scale slowed and the scan improved.