I get that I probably shouldn't be thinking about this from a scientific standpoint, but among all the other things, there's one thing that keeps needling me on the back of my mind. They transform way more often than those in other sex switching manga, and since it's attributed to genes instead of magic mumbo jumbo, I would have to assume the growth and removal of flesh, and everything else, takes actual calories and nutrients. A lot of them. So it's a good thing Sakura is rich enough to afford higher food intake and Ajiro has his mom to hunt for... sustenance. Actually, I don't know what the nutritional value of bear is, but a high protein, calorie, and calcium diet would help