So much for Fred Flintstone's brontosaurus ribs.
The popular caveman diet claims people will feel more powerful and healthier if they only eat items popular during the Paleolithic, pointing to nuts, berries and red meat. But a new study from Oxford University says meat wasn't making it for our ancient ancestors: 2.4 million years ago, man survived mainly on "tiger nuts" -- edible grass bulbs still eaten in parts of the world today.
"Tiger nuts, still sold in health food shops as well as being widely used for grinding down and baking in many countries, would be relatively easy to find," explained Gabriele Macho with Oxford University's Research Laboratory for Archaeology and the History of Art.
"They also provided a good source of nourishment for a medium-sized hominin with a large brain. This is why these hominins were able to survive for around one million years because they could successfully forage – even through periods of climatic change.
But early man couldn't live on nuts alone, of course, and Fred Flintstone was likely no exception. These early relatives may have also sought additional nourishment from fruits and invertebrates, like worms and grasshoppers, the study concluded.