Comment by AngryData

I don't know if I can accept that offhand because high levels of muscle atrophy is a human adapted trait specifically to save calories for the brain. If muscle maintenance costs were so insignificant why would we have adapted a trait to make us physically weaker?

This is anecdotal but the difference between what I can eat working on a farm with having lots of muscle mass and sitting around on a computer with that same muscle mass was not really significant. But the difference between sitting at a desk with a lot of muscle mass and sitting at a desk with noticeably less muscle mass is night and day in how much I have to eat. With small and inconsistent amounts of strength exercise to maintain a bit more muscle mass again, my caloric expenditure went back up, far beyond what is lost from the exercise itself.