Bucking the philosophical underpinnings of the popular Paleo Diet—which invokes habits of ancient peoples to emphasize eating large amounts of meat and shunning carbohydrates—a new study of ancient Andean remains indicates that those societies actually preferred to primarily consume plants. Thanks to new archaeological analytical techniques, researchers can now better determine ancient diets based on how isotopes bind to the bones; the results suggest that the diet of prehistoric populations comprised 80 percent plants—heavy on tubers—and only 20 percent meat.