Last year my vet told me to switch from Purina Cat Chow to Iams Weight control 'cause my 7 year old cat was almost 15 pounds. He's still a porker even though he gets less than a cup a day. :shrug: I read somewhere that you're supposed to change their food gradually over 5 days but I ended up mixing in the new food with the old over a period of a month. I didn't want any more digestion problems with him. He eats plastic (grocery bags, ziploc bags etc.) and it got lodged in his stomach so it cost $1000 for surgery. I don't even think he noticed that his food was changed.

