hon I am overweight and my OB always makes me do the 3 hour test every time, This time we are doing it earlier at 26 weeks. My frist two pregnances didnt have GD, havent had the test this time yet. My pathology always gives me a diet to follow for 3 days before the test on what to eat, it maybe different in different states. I have to ring up and book the test and thats when they give me the diet over over the phone or if I see them personally before the test.