Does fasting for 12 hrs really make that much of a difference in your cholesterol test?

Answer 1

Yes, although you really only need to fast for 8. A cholesterol test measures the amount of cholesterol in your blood, which can rise dramatically after a meal (though it falls after that as the lipids are taken into the cells). Only a fasting lipid profile will give you an accurate measure of the "real" lipid levels, and all of the studies that were done on cholesterol and the effects of lowering it were done with fasting levels, so nonfasting levels are very hard to interpret correctly.

Answer 2

no as long as you did not have a fatty meal immediately before the rest.