Not as far as I know. The ratio of fat-to-muscle loss depends on several factors, most notably the rate of weight loss (see https://pubmed.ncbi.nlm.nih.gov/34371981/). In fact, retatrutide is popular notably because it is known to preserve lean body mass better than other weight loss drugs.
> because it is known to
I thought that this was not yet substantiated in human trials? There's a plausible mechanism and, I think a mouse trial, right?