The term “complete protein” refers to foods or combinations of different foods that contain all essential amino acids and stems from a study that was conducted over a century ago. It is an old myth that you need to eat grains and beans at the same time to produce a complete amino acid pattern that mimics human body protein — this has turned out to be unnecessary! Our bodies maintain a reserve pool of different amino acids from various sources for later use, which means we can do our own “complementing.” Plus, all plant-based foods contain all nine essential amino acids — just in varying amounts.