Okinawa, one of the longest-lived and healthiest populations in the world, practice a principle they call hara hachi bu: Eat until you are 80 percent full.

Don't eat anything your great-grandmother wouldn't recognize as food. Don't eat anything with more than five ingredients, or ingredients you can't pronounce.

In 2008, a year of supposed 'food crisis', we grew enough food to feed 11 billion people. Most of it was not eaten by humans as food, however.

That eating should be foremost about bodily health is a relatively new and, I think, destructive idea-destructive not just the pleasure of eating, which would be bad enough, but paradoxically of our health as well. Indeed, no people on earth worry more about the health consequences of their food choices than we Americans-and no people suffer from as many diet-related problems. We are becoming a nation of orthorexics: people with an unhealthy obsession with healthy eating.

Eat food. Not too much. Mostly plants. That, more or less, is the short answer to the supposedly incredibly complicated and confusing question of what we humans should eat in order to be maximally healthy.

The best farming systems are ones where animals and plants are put into a synergistic relationship.

Don't ingest foods made in places where everyone is required to wear a surgical cap.