Will eating high cholesterol foods the night before a lipids lab test affect my results?

Minimally, if at all. Remember most of the cholesterol in your body is made by your liver. Only about 1/4 of it comes in through your diet, and if you are adequately fasting (at least 8 hours), most of the dietary cholesterol should be out of your system. Also, the total and HDL (good) cholesterols are not affected much by diet, and can be checked without fasting.