New or unregulated diabetic kitties are hungrier because the diabetes makes it difficult for their bodies to metabolize food, so Fluffy may be hungrier cause of the diabetes or from turning down your efforts to change the diet. On the food, I didn't know it until I tried to change my kitty Max's diet, but he is sure a finicky eater. He loved the high carb dry food I was feeding him (had no idea it was so high in carbs and so bad) and hated it when I tried to switch him to the low carb wet diet. You may have already tried this, but I would try a selection of brands and flavors and see if you can find one that Fluffy and the other kitties like better than the others. I was having a really hard time with Max, and then I finally found the one and only flavor of wet he will eat consistently (Fancy Feast Classic - Chicken, not even the other FF flavors, just chicken, but there are many not too expensive options like Friskies, 9 Lives). Paws crossed you can find the one for Fluffy. There may be some lower carb dry food options, but I think the carbs are still pretty high for a diabetic. The diet change made a big difference for Max so don't give up and good luck!
