At home I serve the kind of food I know the story behind.

Once you introduce the issue to young people and suggest to them that they have the ability to vote with their forks, either by positively going for certain kinds of foods or rejecting other kinds of foods, they realize that this is a responsibility and an opportunity to shape the world a little bit by their own choices.

Eat food. Not too much. Mostly plants.

I get letters from classes all the time. Say it's assigned in someone's 8th grade class, and the teacher asks everyone to write a letter to me about their impressions and what they learned. So, it's incredibly gratifying to hear.

Do all your eating at a table.

Fairness forces you - even when you're writing a piece highly critical of, say, genetically modified food, as I have done - to make sure you represent the other side as extensively and as accurately as you possibly can.

American farmers produced 600 more calories per person per day in 2000 than they did in 1980. But some calories got cheaper than others: Since 1980, the price of sweeteners and added fats (most of them derived, respectively, from subsidized corn and subsidized soybeans), dropped 20 percent, while the price of fresh fruits and vegetables increased by 40 percent.