Glucose tolerance refers to the glucose tolerance test (OGTT), which is usually done in the morning and not in the afternoon.
The OGTT test requires fasting after 10 p.m. the day before the test until early the next morning, drinking 75g of sugar water prepared with anhydrous glucose in a fasting state, and determining blood glucose at 30 minutes, 60 minutes, 120 minutes, and 180 minutes after fasting and oral glucose intake, so it cannot be done in the afternoon because doing it in the afternoon will make the patient starve for a long period of time, resulting in low blood glucose.
In addition, OGTT test in order to ensure accuracy, do not exercise strenuously and emotional excitement during the test, avoid drinking coffee, strong tea; 3 days before the test daily diet needs to contain at least 150g of carbohydrates.
Glucose tolerance test needs to be conducted under the guidance of a doctor.