Coffee is one of the specific items Mayo Clinic advises people to avoid while fasting before a cholesterol test. Typically, doctors ask people to fast for nine to 12 hours before a cholesterol test and drink nothing but water.
Some studies have actually shown coffee has little effect on cholesterol results, but the jury is still out as of 2014, according to Everyday Health. It is generally believed that total cholesterol scores and HDL scores are unaffected by drinking coffee. Doctors have concerns that triglyceride and LDL scores do not read accurately without proper fasting. Given the uncertainty, the safest approach is to avoid coffee until testing is complete.