So if you are reading this and you don't understand the problem, let me fill you in. If you are diabetic, sugar is not your friend! Especially excess amounts. Your body does not have a good way of processing that sugar. And excess sugar in the system causes harm to all vital organs. When that sugar gets to a certain high level, you can become groggy, light headed, feel faint and possibly end up in a coma or worse.
Now, let's say you don't end up in a coma, but you thoroughly enjoy that lemonade and you happen to have an open sore on your foot. Well, bacteria love sugar so basically you just gave them a meal of a lifetime! This causes more bacteria to grow leading to infection that could lead to a hospital stay, surgery or even amputation.
Wow! All that from a simple lemonade! Well, lesson here is to always ask for diet. And if you aren't sure about it, return and just get water. At least with water, you never have to worry about the sugar or calorie content!