There are still hunter-gatherer societies in the world, just as there were in prehistory.
They obtain their food by hunting, gathering and fishing, and tend not to suffer from diseases of affluence like high blood pressure, clogged arteries and cardiovascular disease. So should we all start eating like hunter-gatherers, enjoying a largely meat-based diet? It has been found that meat is often in very short supply. So in lean times, their diet consists mainly of plants and tubers, supplemented with fruit and honey.