what sources does protein come from
1 Proteins derived from plant foods (legumes, seeds, grains, and vegetables) can be complete as well (examples include chickpeas, black beans, pumpkin seeds, cashews, cauliflower, quinoa, pistachios, turnip greens, black-eyed peas, and soy).2  Most plant foods tend to have less of one or more essential amino acid. Proteins derived from plant foods (legumes, seeds, grains, and vegetables) can be complete as well (examples include chickpeas, black beans, pumpkin seeds, cashews, cauliflower, quinoa, pistachios, turnip greens, black-eyed peas, and soy).