I have two adult cats and two kittens. I free feed them all Felidae. It is for all life stages, is this ok? Since I free feed if I were to feed just kitten food the two adult cats would eat it too. Also i have to leave food out at all times cause Fez is so skinny and he eats threwout the day. So should i keep them all on Felidae or put all of them on kitten food???Thanks!