A 2-hour postprandial blood glucose value of less than 7.8mmol/L is considered normal. Normal people’s 2-hour postprandial blood glucose value should be less than 7.8mmol/L. When the OGTT, or glucose tolerance test, when the 2-hour postprandial blood glucose is 7.8~11.1mmol/L, it is considered to be glucose tolerance abnormality, which suggests that insulin resistance already exists in the body, and it is the precursor to the occurrence of diabetes mellitus; when the 2-hour postprandial blood glucose is higher than 11.1mmol/L, it is considered to be diabetes mellitus. There are many types of diabetes, the most common is type 2 diabetes, accounting for more than 90%. The amount of insulin secretion needed by the body is closely related to body weight, level of exercise, genetic factors, etc. Obese people are more likely to develop insulin resistance and then diabetes due to their weight and lack of exercise. Many people with type 2 diabetes can reduce insulin resistance early on through dietary control and increased exercise, delaying or even avoiding the development of type 2 diabetes. When the 2-hour postprandial blood glucose is found to be higher than 7.8mmol/L, it is recommended to consult a doctor in time to investigate the cause of elevated blood glucose, and to be diagnosed and treated by a professional physician to avoid delaying the condition.