The blood sugar after eating is called postprandial blood sugar, which is mainly standardized by two-hour postprandial blood sugar. Two-hour postprandial blood sugar is timed from the first bite of meal, and two-hour postprandial blood sugar is normally less than 7.8mmol/L. When the two-hour postprandial blood sugar is between 7.8-11.1mmol/L, it is diagnosed as abnormal glucose tolerance and belongs to pre-diabetes. When the two-hour postprandial blood glucose is greater than or equal to 11.1mmol/L, diabetes can be diagnosed if it has the typical symptoms of diabetes. If there are no typical symptoms of diabetes, fasting or postprandial blood glucose needs to be rechecked at different times to confirm or exclude the diagnosis of diabetes. Therefore, when the two-hour postprandial blood glucose is greater than 7.8 mmol/L, there may be abnormal glucose tolerance or diabetes, and it is necessary to treat diabetes with diet and exercise, and pay attention to monitoring blood glucose.