I understand fully what all of the folks who have written here are saying. I have lived with this longer than probably all of you, and I still do cringe when someone sees me eat something sweet when my levels are low and they ask "are you supposed to have that?" I am not an angry person by nature, though, so I find that what makes me feel better about stuff like this is if I take it as an opportunity to educate someone. The reality is that we are the rarity among diabetics -- I read once that 90 percent of diabetics are type 2 (don't quote me on this, for the percentages may be changing and the article that gave this number was written a couple of years ago). Most people don't know the difference -- this is not their fault, just that they have never had someone tell them..
So I normally respond by asking, "Did you know that there are 2 very different diseases that are both called 'diabetes'? Then, I explain that my type is an autoimmune disease similar to lupus or rheumatoid arthritis, whereby my immune system is overactive and that at some point in my earlier years, it was stimulated (when I caught a virus) to attack and kill my pancreas' insulin-producing cells. And I explain that type 2 is insulin resistance, often caused by too many fat cells. (One question and 2 sentences later, and I am almost done with my educational lesson, so this doesn't take very long in a conversation). I go on to say that because my pancreas does not produce insulin, I take insulin by injections, matching the amount to the carb count in whatever I eat. Therefore, I can eat ANYTHING as long as I take appropriate insulin to convert the carbs to energy. If the person I am talking to looks confused, I then say that people who have type 2 diabetes have to be very careful what they eat because they can't take insulin injections to cover their carbs effectively -- they have to lower their carb count and take oral meds to help their bodies use the insulin they produce. I follow by summarizing: "Therefore, type 1 diabetics can eat anything as long as we know the carb count and take appropriate insulin, while type 2 must carefully watch to make sure they don't overdo the carb count in their foods. Two very different treatments."
After this, the person never bothers me again with the "you can't eat that" comment, either because I have educated them or perhaps because I have bored them to tears and they don't want to listen to me explain it again. Either way works. :o)
I am chuckling at the thought of scaring people away from making comments... but truthfully, people just don't know. Type 1 just doesn't get the media coverage and most people who KNOW diabetics in their families know only about type 2. I always make a very big deal over the fact that they are two totally different diseases that just happen to result in the same consequence: elevated glucose levels. I suppose I don't tend to get angry over ignorance -- that's not the person's fault. They just need to be taught. We can all do that easily enough in daily life. You can follow with a comment about how difficult it is to often have to explain this to people who don't know the difference between the two types and how they are treated. A really super polite response after the explanation would be something like this:
"I really appreciate the fact that you care enough about me to ask me about my diet. However, I know exactly what I need to do to balance my glucose levels with food, so don't worry about me. All type 1 diabetics absolutely MUST have some carbs in their bodies at all times for the insulin to work on so we don't drop too low and pass out completely." A gracious reply like this leaves the person feeling like we appreciate their friendship or caring, but politely lets them know that we know what we are doing and do it deliberately.
Hope this offers some of you a possible way to handle it. I have NEVER explained to a person and had them say, "Oh, I knew that." They always thank me and tell me that they didn't know the differences. They will then hopefully never both another type 1 person with a comment like this again. So by explaining, we are not only helping ourselves, but also other type 1 folks by spreading education around.