These next few rules are very short so I figured I'd post them all together. No one wants to read just one sentence! Enjoy.
#18 Don't ingest foods made in places where everyone is required to wear a surgical cap.
#19 If it came from a plant, eat it; if it was made in a plant, don't.
#20 It's not food if it arrived through the window of your car.
#21 It's not food if it's called by the same name in every language. (Think Big Mac, Cheetos, or Pringles.)
-Michael Pollan, Food Rules