I think it is very interesting that a study of eating habits of past and some present cultures on this planet shows that the balancing of amino acid was naturally done without having any of the laboratory information now available.
In the Far East, primarily soybeans, adzuki and mung beans were used with rice or millet. In the Middle East, primarily garbanzo and fava beans with rice and wheat were used. In South America, corn and beans, etc. In Peru, quinoa is used, which is a complete protein unto itself
Learn more: http://www.naturalnews.com/035342_nutrition_carbohydrates_proteins.html#ixzz1rg0bMVU3