In the past, a test for measuring cholesterol levels was typically done by drawing blood after you fasted overnight. According to the latest guideline from the American Heart Association (AHA) and the American College of Cardiology (ACC), most people who don’t take statins or other cholesterol-lowering drugs no longer need to fast (though it’s still OK to do so).
A simple blood test that can be done on the spot in your doctor’s office is accurate enough to get a reliable baseline reading of cholesterol numbers. However, if you’ve ingested an extremely high-fat meal in the past eight hours, your results may be inaccurate, so your doctor might suggest you be tested at another time when you’ve eaten a lighter meal or are fasting.
In some cases, you may not be able to skip fasting. For example, you’ll still need to fast if:
- You’re already taking statins or another cholesterol-lowering drug
- An initial nonfasting test reveals high triglyceride levels, in which case you’ll need to undergo a second test, this time after fasting
- You have a family history of premature cardiovascular disease (occurring in a male relative younger than 55 or a female relative younger than 65)
- You have a personal or family history of familial hyperlipidemia, a genetic condition that predisposes people to abnormally high cholesterol
The new guideline was simultaneously published in Circulation and the Journal of the American College of Cardiology in November 2018.