Yeah, they worried about renal failure, that's a bust. They worry about bone loss, they gonna find it's also a bust. They worry about animal-plant protein ratio, another bust to find. Next, maybe they gonna try low-carb just for kicks and find that's some awesome stuff. But there's the problem of lower overall food intake in spaceflight, low-carb won't fix that, it's gonna make it worse cuz hunger just drops. Maybe at some point they gonna look at direct hormone/enzyme therapy, like ghrelin analogs to increase food intake cuz it works real well for that, then at myostatin/follistatin to increase muscle mass, and maybe at GH and testosterone and other stuff shunned on Earth. Or maybe they've already been looking at that privately cuz you know how it goes with that stuff.