how long to fast for common blood work
However, blood tests that do not demand fasting may require you to omit certain foods from your diet altogether. Certain foods may influence the results of blood tests, thereby leading to a false diagnosis. The type of foods to avoid before a blood test depend upon the type of blood test that you are planning to undergo. Foods to Avoid Before a Blood Test Fasting for blood work usually begins 8 to 12 hours before the blood test. During this time, you are not supposed to eat or drink anything (though, some tests may allow drinking water). Given below are some foods that you should avoid for common blood tests.