Mine was all done in A&E, where the diabetes was diagnosed, so had no warning or knowledge of the test. From what I understand there are different levels but if they haven't asked about food intake not sure how they can say if mine was low or high. If it was a fasting test it was just above normal but depending on which set of bloods it was it could have been after the bag of crisps or the sandwich, in which case from what I can read up on it, it was low. Getting something non carb to eat which is also gluten free is not easy when in A&E!I think there are different ranges depending on whether the test is done 'stimulated' i.e. eating carbs or 'non stimulated' i.e. fasting. People would normally be told what to do before the test.