In normal patients, blood glucose usually increases, almost reaching its peak 0.5—1.5 hours after a meal; it begins to decrease, coming back to its normal range 2—3 hours after a meal. For several hours after a meal, the level remains in the same stable state as before meals. With three meals a day, blood glucose fluctuations between 5-6 hours. Little fluctuations mean normal pancreatic function, insulin secretion and glucose absorption.