For a healthier planet, eat these 50 foods, campaign urges

A farmer inspects a plant in her dry maize field.
Just three crops -- wheat, corn and rice -- make up nearly 60 percent of the plant-based calories in most diets, according to a new report. Above, a farmer inspects a plant in her dry maize field on March 13 in Zimbabwe.
Jekesai Njikizana | AFP | Getty Images