Sue, he eats like a vacuum and he wakes us up every day even though we can't feed him until a certain time, he seems like he's hungry all the time! Also, he's definitely not constipated but he isn't going too much so everything seems normal there.
I was petting him while he was devouring his food just now and I don't know if I'm imagining it but he did seem a tiny bit less bony so maybe he's slowly coming around? I hope so!
As far as trying other food options, so far it's been BFF or nothing, for such a hungry cat he is awfully picky :roll: