The Paleolithic diet, or caveman diet, is a diet ‘craze’ that has become popular in recent times. The dietary approach is based on ‘eating the way our ancestors did’ – an idea that in some form has been around since the 1960s, but has gained much more opoulatiry in recent years.
However, new research has questioned the accuracy of the modern ‘paleo’ diet – suggesting that following the actual Palaeolithic diet would give modern calorie-counters great freedom, because those ancestral diets likely differed substantially over time and space.
Led by researchers at Georgia State University and Kent State University, and published in The Quarterly Review of Biology, the research team examined the anatomical, paleoenvironmental and chemical evidence for the paleo, as well as the feeding behaviour of living animals.
Led by distinguished anthropologist Professor Owen Lovejoy, the team report that while early hominids were not great hunters, and their dentition was not great for exploiting many specific categories of plant food, they were most likely dietary "jacks-of-all-trades."
"Based on evidence that's been gathered over many decades, there's very little evidence that any early hominids had very specialized diets or there were specific food categories that seemed particularly important," said Dr Ken Sayers, a co-author of the research.
So what was a Paleo diet, and can we replicate it?
The team offer several points that need to be considered by people wishing to emulate the diets of our ancestors:
Firstly, whey warned that it's ‘very difficult’ to characterise what the Paleo diet really was.
They suggested that while advocates suggest certain types of foods and a percentage of energy that should come from protein, fats and carbohydrates, these recommendations are based largely on estimations from a limited number of modern human hunter-gatherers. The diet of early humans was almost certainly much broader, says Lovejoy and his colleagues.
"I think that you would certainly have lots of variation way beyond what those recommendations are," Sayers added.
In addition, the team added that our ancestors lived in a wide range of environments, which affected the types of food available. This is clearly observed, even today, they said – noting adding that modern hunter-gatherers in a northern climate may have an almost exclusively animal-based diet, while hunter-gatherers near the equator might rely heavily on plant-based resources.
Furthermore, even the "same food" isn't the same today as it was during the Palaeolithic era.
"The foods that we're eating today, even in the case of fruits and vegetables, have been selected for desirable properties and would differ from what our ancestors were eating,” Sayers warned.
Was a paleo diet even healthy?
According to Lovejoy and his team, early humans had much shorter life spans than today - so it's difficult to say if their diet was "healthier."
"Individuals throughout the vast majority of the Stone Age were not living that long. Life expectancies are so high today, at least in many regions of the globe," Sayers said. "A lot of the diseases that do come about today or have been linked with high-fat diets or things like that have been referred to by some researchers as 'diseases of affluence.' They're diseases that come about simply because we're living long enough that they can show their effects."
They noted that in recent years, controlled studies have compared the Paleo diet with alternative approaches, and with respect to particular health issues, nutritionists are largely taking a ‘wait-and-see’ attitude towards them.
However, Sayers and colleagues did also noted that our early human ancestors were focused on survival, and not necessarily eating a balanced diet.
"Throughout the vast majority of our evolutionary history, balancing the diet was not a big issue," said Sayers. "They were simply acquiring enough calories to survive and reproduce.”
“Everyone would agree that ancestral diets didn't include Twinkies, but I'm sure our ancestors would have eaten them if they grew on trees,” he said.