If you consider how we live in the Western world today very little resembles the way our hunter-gatherer ancestors lived 10,000 years ago.
We live in houses, sleep in beds, travel by cars and planes. We build bridges and skyscrapers. We can read and write.
While most people are happy to exist in the present, when it comes to food, growing numbers of people are abandoning modern diets and returning to the food habits of our primitive forebears in the Paleolithic period, between 2.5 million and 10,000 years ago.
Broadly speaking, proponents of the Paleolithic, or paleo diet, believe longevity and good health comes from eating mostly fish, meat and vegetables – foods we presume ancient hunter-gatherers ate before the advent of agriculture and industry.
Paleo followers eschew grains, dairy and processed foods.
But the logic of the diet fails for a couple of reasons; it oversimplifies what early hunter-gatherers ate, and it assumes humans haven’t evolved since the stone age.
So what do we know about the feeding habits of our Paleolithic ancestors, and how relevant are those habits to our own wellbeing?
While scientists cannot return to watch our ancestors prepare their meals, studies of archaeological remains, such as pottery and shells, combined with research on skeletal remains, particularly fossilised teeth, reveal many clues about their diets.
Significant insights have also come from observing contemporary hunter-gatherers, such as the Kalahari bushmen in southern Africa.
Professor Vanessa Hayes, a geneticist who works with African populations, says, unsurprisingly, the diet of contemporary hunter-gatherers is based on what they can gather.
But apart from this commonality, their diets vary significantly, depending on climate and geography, says Professor Hayes, from the Garvan Institute of Medical Research.
“The basic diet of the hunter-gatherers in the Kalahari is the bush potato, bush cucumber and the manketti nut,” she says.
But travel to a community 500 kilometres further south and a type of raisin berry is the centrepiece of their diet.
Where traditional hunter-gatherer diets diverge significantly from the paleo craze is meat consumption.
Professor Hayes says meat was not a daily staple of ancient ethnic groups in Africa.
“Meat was a celebration [because] you had to expend a lot of energy on the hunt,” she says.
After a successful catch, the entire beast was consumed, more or less, at once.
“The hunter-gatherer diet was one based on stuffing yourself until everything was eaten, then you may live three or four days without eating at all,” she says.
“I don’t think anyone [today] would advocate that.”
Professor David Raubenheimer, a nutritional biologist at the Charles Perkins Centre at the University of Sydney, says studies that examine what types of food were available also tells scientists about the food habits of these groups.