There are few areas of modern life that are burdened by as much information and advice, often contradictory, as our diet and health: eat a lot of meat, eat no meat; whole grains are healthy, whole grains are a disaster; eat everything in moderation; eat only certain foods—and on and on. In , biological anthropologist Stephen Le explains how cuisines of different cultures are a result of centuries of evolution, finely tuned to our biology and surroundings. Today many cultures have strayed from their ancestral diets, relying instead on mass-produced food often made with chemicals that may be contributing to a rise in so-called Western diseases, such as cancer, heart disease, and obesity.