For the study, researchers compared cholesterol testing results of 300,000 people from Denmark, Canada, and the U.S. In both the U.S. and Canada, fasting for eight hours before a test is required. In Denmark, however, it is not.
Patients who are scheduled for a lipid profile test should fast (except for water) for 12-14 hours before the blood sample is drawn. If the patient's cholesterol is to be fractionated, he or she also should avoid alcohol for 24 hours before the test. http://www.healthatoz.com/healthatoz/Ato...
Among the studies that found that fasting may have little impact on cholesterol blood test results was a large 2012 Canadian study of more than 200,000 people that found average levels for HDL and total cholesterol varied less than 2 percent, regardless of whether people had eaten an hour earlier or fasted for 16 hours.