| I always carry my glucose tabs with me, and a juice box and granola bars if I'm planning to be in a setting such as you described. Haven't had any trouble bringing food like this inside anywhere, including theme parks (Canada's Wonderland, for example). Once I mention that I am diabetic, I usually don't have to explain any further. It's not like I'm carrying a full lunch, just enough carbs to get myself through any kind of lineup. I've also had my meter, insulin pens, and medic alert id on hand, but really, it never gets that far. Security is usually afraid of getting picked by a needle, so they do not really open anything, but be prepared to open your cases for them, in the event that you meet up with an inquisitive security guard. | 
