My doc said I didnt have to fast for the 1 hour..just not to have anything sugary for breakfast that morning. I scrambled myself some eggs & drank a bottle of water & passed without a problem.
You're doctor should have told you, but to get an accurate reading of how your body handles an intense amount of sugar at one time, you should be fasting for 8 hours.
Just make sure you dont eat anything extra sweet or fast food within an hour or 2 of drinking the bottle because it can skew your results and force you to do the 3hr.