km-I have had two really large cats in my life, and most were at least a little chunky. Years ago they were all inside/outside, now they are all inside only. All had many exercise options and few table scraps. Yet I have never had any success in getting a cat to lose weight. My first large cat, Zebo, weighed 16 lbs, but he was a very large cat anyway - his ideal weight probably would have been about 13 lbs. He never suffered any arthritis, diabetes, or anything weight-related. I tried every way I knew of to take some weight off him, including many of the prescribed diets, and nothing worked. Conversely, when he eventually had to go on the relatively high-calorie kindey diet, he did not gain weight. I have a cat now that weighs 17 lbs. I have his entire family - his mom was still just a kitten weighing 7 lbs even though she was pregnant when I took her in. She now weighs just under 10. His sisters weigh 8 and 9 lbs. They were all raised the same, with the same amount of food and exercise. In fact, Big got fat on mother's milk - at 6 weeks he was already 3 lbs, and when he was neutered at 4 months he already weighed 8 lbs. Again, he is a naturally large cat who probably would weigh about 14 lbs if he were lean. My mom has a very fat calico, Lacy. She was very concerned about her weight, but her vet told her it was a genetic problem linked to the calico gene, and probably no amount of dieting would help her. Lacy is gettin up in years and has no health problems. So, my ultimate question after all this history - is putting a cat on a diet an act of futility? Is it not largely genetic? All these cats were fed the same diets and got the same amount of exercise as their biological and house brothers and sisters. And if nothing can be done, are they really at more risk for certain diseases? Anyone else have any insight? This is something that concerned me with Zebo, and it has cropped up again since Big was born.