I am having surgery on June 15 and I am on day 3 of 5 of the preop diet. I have only had my shakes but I am dying for real food. I know from being on the Atkins diet before, your body burns what carbs that are in your blood first. Our problem is we used to take in too many before they could be burned. If you have been pretty faithful and on your diet for some duration you stay strong for the rest of the weekend. You should be good.