Need to fast from 12mn onwards. First, they will take ur blood sample. Afterwhich, u will be given a bottle of glucose syrup which u need to finish. They will take blood sample again every 1 hour for 2 times. U cant eat until the test is over, but u are allowed to take sips of water.
U need to fast 8hrs. Once u at clinic, nurse take 1st blood tube. Then give u drink orange syrup. Then u cont to be fasted. For the nxt 2 blood tube. U only can eat after 3 blood tubes taken. U cant vomit out the orange syrup.