Liz Buchanan BVSc MRCVS
Hi! That's tricky because kittens have to double, triple, quadruple in size very quickly and they need the right nutrients to do that, so what is making your big cat fat may be ideal for your kitten (check with your vet as I don't know what you're feeding or your cats!) Rather, I wonder if kitten could have a specific feeding time on their own with the door shut, and then just take up the bowl with what they haven't eaten? (In time I guess you learn how much to put down). Definitely something to talk over with your vet - or perhaps the practice nurse, as they are usually better at that kind of thing than the vets are!