There really is no right answer; it is different for everyone. There have been several threads on this topic already that you might find helpful...look in the Foods and Nutritition forum to start and you will see several different thoughts.
"If you drop an egg, you don't say, 'Oh, shoot' and drop the other 11, do you?"
-Source unknown, but obviously brilliant
Reached goal 4/16/2010...but kind of afraid to look these days