"Serve a proper portion and don't go back for seconds."
Portion sizes have gotten out of control in our supersized culture, so what exactly is a proper portion size? You'll find different theories on this, but the easiest for me to remember is that a serving of animal protein should fit in your plam, a serving of veggies should fill both of your cupped hands, fruit fills one cupped hand, a serving of grains is the size of your fist, and fat or oils should be no larger than the size of your thumb. If you still decide that you HAVE to have seconds, at least wait several minutes before going back. After giving yourself a few minutes, you may discover that you really don't need more, or at least not as much as you thought.
All the tips given for the 28 Days of Real Food Challenge were compiled from "Food Rules", by Michael Pollan.