For normal people, eating sweets the day before the blood glucose test will not affect blood glucose as long as the fasting state is maintained for 8~10 hours; for diabetic patients, eating sweets the day before the blood glucose test may have an effect. Normal people will have higher blood glucose after eating sweets, and accordingly the body will secrete a certain amount of insulin to control the elevated blood glucose concentration in order to maintain the stability of blood glucose. Therefore, normal people who eat sweets will not be affected by fasting blood glucose measurement as long as they keep fasting for 8~10 hours. Diabetic patients may be accompanied by absolute lack of insulin or insufficient insulin secretion, insulin resistance and other abnormalities, if the day before the blood glucose measurement ate sweets, and the body is unable to produce the appropriate insulin to control elevated blood glucose may have an impact on the next day’s blood glucose measurement. It is recommended to go to the hospital if you have abnormal blood glucose values.