Being a type-I diabetic I feel qualified to explain something. And I WANT to do it because I am always being asked the same questions, in bars, at work, in airports, in dog kennels: "How can you eat sweet things when you're diabetic?"
There is a misconception about sugar and diabetes. If you already know this, skip over it. If not, though, read carefully...it will make the next diabetic you meet very, very happy:
Diabetes is not about avoiding sugar, it's about REGULATING food intake. When other people eat food, they break down the food into sugars that circulate in their blood. They then NATURALLY produce insulin to remove the sugars from the blood and turn it into energy, or fat, or whatever. It's all taken care of in that well-balanced, finely-tuned, slightly gross thing we call a "body."
Type-I diabetics cannot produce that insulin, so the sugars -- derived from the food they've eaten -- just stay in the blood, floating around and making us feel awful. This isn't a good thing because your blood isn't supposed to be THAT full of sugar, and because your cells need the sugar. So diabetics INJECT insulin to remove that sugar. If diabetics inject TOO MUCH insulin, the amount of sugar in the blood gets too low and the cells -- particularly in the brain -- begin to starve. This is an "insulin reaction." It's why, when diabetics collapse, you're supposed to force-feed them sweet things.
It's also why, occasionally, I say really stupid things.
My point is: EVERYBODY needs sugar, carbohydrates, food. Diabetics too. But diabetics need to keep track of the amount of carbohydrates they've eaten, and inject an appropriate amount of insulin to get the resulting sugar out of the blood. I can eat a whole box of sugar if I want to, and everything will be fine as long as I inject enough insulin to take care of it. So next time you see me eating a candy bar, don't say "diabetics aren't supposed to eat sugar," or I'll grab you by the ear and yank really hard.
NOTE: Anybody who eats a whole box of sugar needs help, diabetic or no.