What was the last grain you ate? Chances are very good it was wheat, corn or rice, the grain triad that directly contributes more than half of all calories consumed by humans worldwide. Early on humans recognized food that was relatively easy to process, with high yields (and therefore high calories) and good taste. Each grain traveled far from its origins long before agricultural industrialization. Already familiar to most people, and aided by modern practices, the triad was in the perfect position to dominate the modern food grain market.