We have 2 cats, Tonks, who is 16.2 lb and Mac who is 10.8. Mac and Tonks are brothers and have been together since birth, they are on a scheduled feeding time on diet food to keep them down, mostly for Mac's sake so keep from over stressing his lame elbow. Mac has gone down to a healthy weight but Tonks keeps gaining. We also just got a new puppy about 3 weeks ago. Mac has always been very open to her but Tonks has always been very stand offish and has just now started coming back down stairs. We keep the puppy from every going up stairs so the cats have a safe place but now when we put the food down Tonk instantly eats. He doesn't eat the whole thing since it's 2 servings at once (both cats have always eaten out of the same dish). We're worried about Mac loosing too much weight and Tonks is already 6 lbs overweight.I'm worried about feeding them separately because Mac doesn't instantly eat when we put food down. I'm also worried about the cats feeling neglected due to the puppy. Help!