Catt31,
The kitten was on kitten food for a few months, but he always seemed to want to eat the older cat's food (and vice versa). The overweight cat's weight is verging on unhealthy, so I'm naturally more concerned with what he's eating. Also, I beginning to think part of the reason the overweight cat is overweight is because he was on kitten food for almost a full year!
I think what I'm going to do it feed them all the RC Indoor and give the kitten canned kitten food and cat's milk to supplement. Seems like the best/simplest solution.
Thanks!