[coffeecantcode]

Not an expert, but from my own research muscle will always atrophy to its functionally base necessary mass, there are of course genetics involved in muscle mass retention as well that can’t be overlooked. But you can be in a caloric deficit and your body is burning fat(which often times this leads to lower energy and less intense resistance training) while still losing muscle mass. I don’t believe they’re mutually exclusive.

You’re 100% right though, the key to retaining muscle mass while in a caloric deficit is consuming sufficient protein, or even over-consuming protein. In starvation situations muscle is next up after fat when getting consumed for energy but it seems like for the most part the muscle mass deterioration during significant weight loss periods is a natural side effect of the process and lifestyle required to accomplish it.

[aaronblohowiak]

>1) compared with persons with normal weight, those with obesity have more muscle mass but poor muscle quality; 2) diet-induced weight loss reduces muscle mass without adversely affecting muscle strength; 3) weight loss improves global physical function, most likely because of reduced fat mass; 4) high protein intake helps preserve lean body and muscle mass during weight loss but does not improve muscle strength and could have adverse effects on metabolic function; 5) both endurance- and resistance-type exercise help preserve muscle mass during weight loss, and resistance-type exercise also improves muscle strength. We therefore conclude that weight-loss therapy, including a hypocaloric diet with adequate (but not excessive) protein intake and increased physical activity (particularly resistance-type exercise), should be promoted to maintain muscle mass and improve muscle strength and physical function in persons with obesity.

https://pmc.ncbi.nlm.nih.gov/articles/PMC5421125/