Fat is pure evil. Pizza spikes can happen anywhere between 3 and 14 hours after eating, and are seriously impossible to predict. Last week it was my mom's birthday so we went out for pizza for lunch. I think that was the first time I'd had pizza at lunchtime rather than dinner, I bolused the full amount upfront and I was pleasantly surprised by the fact that my BGs were almost totally flat on a 200% temp basal from midday (when I ate the pizza) to 10PM (when I went to bed). At about 2AM I woke up sky high with the CGMS alarming at me. It was, undoubtedly, a pizza spike.. And that was 14 hours after eating! When I was on vacation this summer, I had "american style" pizza for the first time (i.e. it had a really thick, doughy base rather than being very flat like the Italian typed pizzas we get over here). My gosh. Whole different ball game.. I didn't think the fat spikes could get worse, but they did. I needed a ridiculous amount of insulin to deal with it. As long as I measure sugar correctly and bolus for it, life is good.