What causes preprandial blood sugar higher than postprandial blood sugar?

In clinical practice, preprandial blood sugar is higher than postprandial blood sugar. Because after eating, if the patient's insulin function is good, it will stimulate a large amount of insulin secretion and cause blood sugar to drop. Preprandial blood sugar, generally not with a large amount of insulin secretion has an absolute relationship, but mainly to see whether the patient has insulin resistance, whether obese patients. Like many patients obese, fat cells are more, and insulin resistance, it will cause high blood sugar before meals, and blood sugar before meals is higher than blood sugar after meals. In addition, one reason is fasting blood sugar in the morning, because of the secretion of a large number of human glucogenic hormones, such as growth hormone, glucocorticoid, glucagon, adrenocortical hormone, etc., which causes high blood sugar before meals.