Jenn, I'm sorry to hear about Calloway. Hopefully the new diet will make him lose the weight that he needs so that his diabetes can be controlled by diet.

When I first stopped free feeding, my cats weren't too thrilled either but they soon learned that they had to eat when I fed them. After about 1 week your cats should learn the routine and do better. I know that if I continued free feeding that Sky, Starr, and Ziggy Stardust would be extemely over weight by now. Good luck.