My cat is responding to the strict diet I put her on in January. She's down to about 11½ pounds from 13 pounds. Target weight is 10 pounds. She's already more active, though that might just be her being angry with me for not feeding her as much. But things like the 4½ foot leap from my desk to my bed that she previously would take a couple minutes to work herself into, she now jumps without giving much thought at all. Of course, I now wake up to her insistence every morning that she be fed now. If she isn't fed by 7 she starts knocking things off my desk, shelf and dresser. She's not quite as fat, happy and contented as she used to be. Once she gets down to around 10 pounds, I'll up her portions a bit so she maintains weight instead of losing it, and perhaps at that point she'll stop whining as much about food.