@silas0307 Aside from beginners, I’ve found surprisingly little research on the best strategies to build muscle mass and burn fat (whatever structure that ends up taking), seemingly because research funding either goes towards improving elite athletes’ performance, towards public health concerns, or towards specific medical conditions. That leaves a vacuum where people (who are doing their best) parrot something they heard that sounds plausible.
The thing that I know about science is that you can’t assume very much, and you have to pay careful attention to what the research isn’t saying. If short-term studies (which are relatively cheap to fund) show that beginners can build muscle mass and burn body fat simultaneously, that leaves us (or at least me) with a lot of questions. Is it only beginners who experience this, or are people who have been regularly active able to have the same phenomenon but to a lesser extent? Or does the phenomenon disappear? What nutrition is required? And more.
The problem is, and people may not like this, the studies I have seen don’t exactly support a lot of the claims I see repeated online, and often when people cite studies, they infer way more from them than the articles actually back up. However, I also don’t have the time, energy, or desire to argue with people online that I don’t know, so I don’t. The hard truth is that plausible sounding “conventional wisdom” is just as often proven wrong as it’s proven right, whenever it finally undergoes rigorous study. So if there’s a lack of scientific consensus on a topic, I just accept that the conventional wisdom is more of a best guess than anything else.
All of that to say, my current understanding is that there’s a lot of open questions in science about how to build muscle mass and lose body fat (because there’s not a lot of research funded towards studying that), and whether that can occur at the same time for non-beginners, or if it can only occur in sequential bulking and cutting cycles, and either way what are the requirements for such a thing to occur. I have my own pet hypotheses but they’re just best guesses like everyone else’s. Wish I could be more helpful.