What is the ruling on making up missed fasts (qada') with the intention of not feeling hungry, especially for a diabetic patient?

Intention (niyyah) cannot accommodate hesitation or conditionality; rather, it must be resolute. Your statement: "If you don't feel hungry, then fast; otherwise, break your fast" is an unresolute and conditional intention, and thus, it is not valid for initiating the fast. Therefore, make your intention to fast resolute, without hesitation, and have your suhoor. If something occurs that makes fasting difficult for you, then it is permissible for you to break your fast.