To be used most efficiently by the body, all the essential amino acids that make up a protein must be present in a food in certain amounts and proportions. Incomplete proteins are missing one or more amino acids or supply small amounts of amino acids. Examples of foods that contain complete protein include beef, poultry, fish, milk, eggs and cheese. Foods considered incomplete-protein sources are typically plant proteins and include beans, rice, grains, peanut butter, nuts, pasta and some vegetables. One exception is soy protein.
Soy protein provides all nine missing amino acids, making it a complete protein.
The soybean is the only vegetable offering a complete protein profile. Various protein sources supply different nutrients, so it is important to eat a variety of foods, both those that contain complete protein and those that contain incomplete protein. The information contained herein is presented in good faith and is not intended to be a replacement for professional medical or related technical advice. Copyright 2000 everything about food. All rights reserved.