This test is done after three days of unrestricted diet and an overnight (10-16 hours) fast. The first fasting glucose sample is taken and then the patient is asked to drink typically Lucozade (or equivalent drink giving the recommended glucose load of 75g for adults, or 1.75g/kg for children). After 2 hours another glucose blood sample is taken. If this result is above 7.8 but under 11.1 the diagnosis is Impaired Glucose Tolerance (IGT) but if it is equal or above 11.1 a diagnosis of diabetes is clear.