To drain fat or not?

If you are talking about cooking the meat in the pan with oil (or butter, lard, etc), then you would also include the amount you are using. You can serve the entire contents of the pan. You will have the nutrient values for everything. For instance, if the ingredient says pan-fried, then the nutrient values were calculated for this food after being pan-fried.

I hope I am understanding your question.

Pan fried hamberger, serve with the remaining liquid fat or not?

Please drain the remaining liquid fat before serving.

Obviously draining excess fat would effect the calories.