feeding of newly-adult cat

Question
I have two cats; one just turned 1 and one is about six months.  We were sent home from the Humane Society both times with Science Diet Kitten Food; I fed my older cat Winston this food exclusively.  When my younger cat was adopted. the vet at her first visit told me about the "Ratkins" approach; I have since been feeding her both Science Diet and canned food.  Why not change to canned food exclusively? Well, Winston won't touch it; a few weeks ago I began to change him over to science diet adult formula and he won't eat that either, even though it is somewhat mixed with the kitten food.  I don't think it could be healthy for Winston to remain on kitten formula forever but I am at a loss...I've never had a cat who wouldn't eat canned food, so he is the pickiest cat I've ever known!  I would appreciate some advice..he won't touch his mixed food and steals the younger cat's grub.

Answer
You can probably keep Winston on the kitten food for six more months but I switched my kitten to an adult food at 6 months because I had a senior cat at the same time.

She did just fine on it. Feeding them wet and dry is fine, but it's how you do it that usually matters. I give a few spoonfuls of wet in the morning and not at night. Dry is measured out and kept in a bowl. He will eat the dry if you just leave it. He won't starve himself.

Just keep Winston on kitten until the other one is one year or switch them both to the adult. That will stop the problem!