It seems the article is now behind a paywall (can only get a reddit link w/ a screenshot atm [0]) but there was a study that showed body composition after 25% weight loss in terms of fat mass and fat-free mass (and the portion of fat-free mass that was skeletal muscle mass) after traditional several interventions, and also compared the breakdown of weight lost in terms of FM and FFM for several GLP-1 medications:

- diet alone

- diet + extra protein

- diet + exercise

- retatrutide

- tirzepatide

- semaglutide

tldr is that, despite some muscle loss, muscle as a percentage of body composition is higher (~50% FFM at start, whereas weight lost with GLP-1 meds ranged from 25%-39% of muscle). It also seems like the muscles will likely function better with less insulin resistance:

> Intentional weight loss causes a greater relative decrease in body fat than FFM or SMM, so the ratio of FFM/SMM to fat mass increases. Accordingly, physical function and mobility improve after weight loss despite the decrease in FFM/SMM, even in older adults with decreased FFM and SMM at baseline. In addition, weight loss improves the “quality” of remaining muscle by decreasing intramyocellular and intermuscular triglycerides and increasing muscle insulin sensitivity

https://www.reddit.com/r/tirzepatidecompound/comments/1dtzr2...