8-10 hrs of fasting required.

Fasting blood sugar levels are measured by taking a blood test after a period of fasting, usually of 8 hours without food. Typically, fasting blood glucose levels are taken in the morning before any breakfast is eaten. When having your fasting blood glucose levels take, you should not have any drinks apart from water during the period of fasting.

 

The test is performed to determine whether or not your blood glucose level is within normal ranges; to screen for, diagnose, and monitor diabetes, and to monitor for the presence of hypoglycaemia (low blood glucose) and hyperglycaemia (high blood glucose).