when does blood sugar spike?

Depends what you eat.
If I eat a lot of protein (e.g. a big steak) I peak at 3 hours!!

Angie

Hi! The idea of testing isn't necessarily to catch your spike; that can occur at anything from 30 mins to 3 hours after eating according to the food. The idea of 2 hour testing is that by then, your BG should be back to a fairly normal level. If its higher than 8.5 (according to NICE guidelines), or some lower target that most of us set such as 7.8 at that2 hour stage, then you should modify what you ate for that meal; normally by reducing the amount of starchy carbs in it. you say you're not diagnosed yet. You should probably wait until you are, then concentrate on these 2 hour tests to modify your diet.