When i had the 2hr test i didnt have the carb diet either but i did have to fast for 12 hours beforehand. Then i had a blood test first, then the drink(which made me absolutely sick!) and then wait an hour and then have another blood test and then wait another hour and have a 3rd blood test. I actually did get to lay down in one of their rooms because i was so sick from the drink and i had a nap.