Why do I need to fast before a GD test?

[Jummynbean]

Looking for a bit more insight here. I ate a late dinner last night, completely for getting that I shouldn't have been eating past 9pm. Just wondering how that will/may affect my results. Will 2 hours make a difference and will that make me pass/fail. And why? How does blood sugar work?

It can give you a false positive, since your blood sugar won't have "reset" with a long enough fast. If you're starting from a higher blood sugar than your fasting rate it will be that much easier to fail, since the spike will be that much higher.

But it will also depend on what you ate. Lean protein and veg would have a lot less impact than a full-on plate of pasta and breadsticks!

Thanks! It was a jacket potato, but when she took my blood sugar level, I was told it was nice and low, so hopefully it won't have interfered x