Human blood glucose may also rise when you don’t eat, because human blood glucose is not only related to diet, but also related to the glucagon in the body. For example, if blood sugar rises in the early morning, on the one hand, it is because hypoglycemia has occurred at night, and hypoglycemia at night reflexively causes high blood sugar in the early morning. On the other hand, it may also be due to the dawn phenomenon of diabetic patients, that is, the secretion of adrenaline, growth hormone and thyroid hormone reaches its peak in the early morning, which antagonizes the hypoglycemic effect of internal insulin, so the blood sugar may rise in the morning. In addition, similar reactions may occur in diabetic patients around 4:00 pm, which is called the twilight phenomenon, mainly because the growth hormone level increases, so there may be an increase in blood glucose level without eating. Therefore, in order to avoid abnormal blood sugar fluctuations, it is recommended to eat three meals on time and avoid having a full meal. Patients with diabetes or elevated blood sugar should pay attention to strict dietary management and not eat or reduce the amount of food with high glycemic index. If blood glucose rises significantly, it is recommended to use medication to maintain a stable blood glucose level as prescribed by the doctor.