you have to eat nothing but veggies for about a week prior to the test. and don't put butter on them.
the main thing is a 12 hour fast before the test. Other than that eat like you normally do.
Cholesterol testing can only be done every three months and there is a reason for that. The testing is an average reading so what has happened in the last 12 or 24 hours will not alter the test all that much. It isn't repeated for three months in order for any changes that have been made to appear on the retesting. The point of the test is to determine your cholesterol and triglyceride levels for the purpose of enhancing your health. If you aren't interested in an accurate result so you can make dietary changes then I must agree with above that there really isn't much point in wasting time and money on this.
Eat like you normally do before the test. That way you will have an accurate assesment from it. Otherwise, don't take the test. Cause it doesn't even make sense to cheat your way through it. It is completely voluntary.