Unfortunately, until the sugar levels are controlled, eating alot with weight loss is a symptom of diabetes. What kind of insulin were you giving? Have you thought of trying others? Did you change your kitty to a high protein, low carb diet? Sometimes that will help bring the levels down. My diabetic cat is being controlled by diet without having to take insulin injections anymore. Check out this website for some tips on feeding. How long has your kitty been diabetic?