I was recently informed that whole rice was essentially unprocessed white rice, which blew my mind. Yet, having spent time in poor areas of several rice-eating countries, the only option was consistently white rice. When and why did we decide to start adding another layer to the generation of these foodstuffs, especially in countries with lower production (not to mention, with lower nutritional value)
This may be more of an AskScience question. I'm not going to be able to provide a complete answer but basically, for white bread it has to do with removing the bran and the germ which helps prolong shelf life. This is because the bran and germ contain oils, so the goal is to dry out the bread ingredients.
When they first started doing this on an industrial scale, the powers that be realized the population was becoming malnourished because essential nutrients were substantially reduced. So fortification was introduced to something like Wonder Bread so you don't need end up eating a whole lot of nothing.
But again this is possibly a better question for a food scientist. Unless you wanted to talk about foods of a really long time ago.