Here are some of my favorite food rules from "Food Rules" by Michael Pollan:
1. Avoid food products that contain more than five ingredients.
2. Only eat food that will eventually rot.
3. Don't eat anything that your Grandmother wouldn't recognize as food. (i.e Lucky Charms, goldfish crackers, GoGerts, etc.)
4. Buy your snacks at the Farmer's Market.
5. If it came from a plant, eat it; if it was made in a plant, don't.
6. Its not food if it arrived through the window of your car.
7. Treat meat as a flavoring or special occasion food.
8. Eat sweet foods as you find them in nature.
9. Eat more like the French. Or the Japanese. Or the Italians. Or the Greeks. (eat traditional foods according to traditional food culture- generally if you eat this way, you WILL be healthier)
10. Breakfast like a King, lunch like a prince, dinner like a pauper.