well, maybe you should change the feeding habits for all of them because they all may get fat like jack gradually. my friend's 2 cats were rather fat and what she did was just put out a certain amount of dry food (maybe 2 cups a day) instead of the "non-stop" container. she also gave them a little can food in the evening. anyway, of course they didn't like it first, but gradually got used to it and lost weight. it's just like with humans - you hate it first and it's very difficult, but if you survive the first days or weeks, you et used to it. unlike humans, they can't get the food themselves, so you have to be the strong one. keep in mind, it's for his (or their) good and good health! you're the more intelligent one! act according to that. just like feeding a child what it should eat not want it wants. good luck. 8-))