I agree that this sounds definitely like a control issue. You say there is plenty of foods in the house that he "doesn't have to do insulin for." Honestly, there are so few things in our cabinet that my daughter doesn't need insulin for (not just sweet things - she's more of a "salt" person anyway), that I think she would be behaving in the same way if I restricted her to only 0 carb snacks. There's only so much meat and cheese that a person can eat before you want something else -- anything else. Everyone wants what they can't have; I think it's human nature. Do you practice these same habits - only eat 0 carb foods outside of meal time? If you don't, I suggest you try it for a month both as a way of supporting your child and to see what a life like that is like and what cravings you might or might not have.