Getting protein by combining foods occurs why? I note that Japanese gohan means both rice and a meal. Is this because in order to get protein, rice has to be combined with other typical ingredients in the diet? Is that why bread figures prominently in every meal in most cultures? 

My interest is not in getting out of the Paleo diet... I'm firmly committed to it..... but just to understand how cultures developed methods over the centuries to extract protein from the diets which did not provide it directly through copious consumption of meats. As an old anthro major, that way of finding the best ways to function without knowing the underlying science fascinates me.
Pat Barrett  [log in to unmask]
http://ideas.lang-learn.us/barrett.php