They used every part of the animal they hunted to survive. However, now we have all kinds of clothing and housing and we are no longer constantly hunted by other animals, so eating their meat is simply a luxury. Before man knew how to hunt larger animals, plants and grains were eaten. It was not an inconvenience and the man lived well. Returning to this way of living would transform the world into a cleaner place and could possibly help the world move to an organic way of living, which would benefit the planet.