In nearly all premodern societies, overwhelmingly vegetarian diets (commonly more than 80%, and even more than 90%, of all food energy was derived from plants) were dominated by a few staple crops. Consumption of four major grains (wheat, rice, millet, and corn), and also of tubers in the tropics and in the Andean highlands, was supplemented by a variety of pulses (lentils—one of the oldest cultivated species—peas, beans,
