Glucose tolerance is the glucose tolerance test, which mainly involves drawing blood to test the blood glucose value, and is an important test to confirm the diagnosis of diabetes mellitus. It is not recommended to control sugar three days before the glucose tolerance test, and is generally required to eat normally for three days before the test. In the three days before the glucose tolerance test, the daily carbohydrate intake should not be less than 150g, which means that you have to eat normally. There is no need to control sugar excessively, but avoid eating too much food with high sugar content, so as to avoid excessive sugar intake affecting the normal level of glucose in the blood, which is not conducive to the doctor’s judgment of the specific situation through the results of the glucose tolerance test. It is recommended that you follow your doctor’s instructions for checkups and seek medical attention if you have any discomfort.