I am having a 'fasting' blood test tomorrow at 9.40am. It's an annual thing because a couple of years ago I was in a medical study and they happened to discover that I have impaired glucose tolerance. So this is just a check-up to make sure I haven't developed diabetes. But I can't remember how many hours I have to have fasted for. I ate my dinner at 7. Do you think if I now have nothing but water from now until the test it will be long enough?