The paleo diet, also known as the hunter-gatherer diet or the Stone Agediet, recommends eating lean meats, fish, fruits, vegetables, and nuts—foods available to our Paleolithic era ancestors—for optimum health in the modern era. The regimen excludes grains and dairy products, since paleo enthusiasts believe those foods emerged in the human diet less than 12,000 years ago, after the advent of agriculture.
But the Paleolithic era began at least 2.5 million years ago, and human diets have altered over that time. Just in the past decade, our impression of what ancient humans ate has changed drastically. If you’re seeking diet advice from some actual paleo humans, try these five rules based on recent archaeological findings that have revolutionized our understanding of the real paleo diet.
1. SCAVENGE YOUR MEAT.
Our first tip takes us to Ethiopia, the cradle of humanity. In 2009, paleoanthropologists there found 3.4-million-year-old animal bones with cut marks from stone tools that indicated butchering. The marks were particularly significant because they suggested that the Paleolithic era, or Old Stone Age—when early human ancestors created and used stone tools—began 800,000 years earlier than previously thought. The animal bones were so old that the beings using the tools weren’t even human; they were early hominins, probably Australopithecus afarensis. Previously, stone tool use was attributed only to our genus, Homo, which emerged about 2.5 million years ago.
The two animal bones came from “an impala-sized creature, the other from one closer in size to a buffalo,” researchers reported in Nature. They concluded that our early ancestors didn’t hunt the game; they scavenged it by butchering the meat from an existing carcass, likely the prey of another large predator. Scavenging is an important step in human evolution that differentiated hominins from apes. “Chimpanzees do not recognize large animals or carcasses killed by other animals as food,” Paleolithic archaeologist David Braun told Nature at the time. “At some point, hominins did.”
2. COOK YOUR DINNER OVER AN OPEN FIRE.
A 300,000-year-old hearth in Israel, reported in the Journal of Archaeological Science in 2014, is the earliest physical evidence of humans consistently building fire over a period of time. The hearth demonstrates that humans controlled fire for their daily needs, which also suggests that the people had a social structure and increased intellectual capacity. Stone tools for butchering and charred animal bones found nearby indicate that the people were cooking meat.
But our cooking skills may go back even further: A deposit of 1-million-year-old ash was found in South Africa’s Wonderwerk Cave. Anthropologist Richard Wrangham has proposed a theory—the Cooking Theory—that suggests learning to cook our food promoted the development of brains that are massive compared to those of other primates. By unlocking nutrients and reducing the time we had to spend chewing, cooking allowed hominins to spend time learning other skills. For this theory to correlate with our known evolutionary path, humans would have had to be cooking with fire about 2 million years ago.
3. EAT YOUR STARCHES AND VEGGIES.
The paleo diet, and other low-carb diets, are famously meat-heavy. That M.O. reflected the prevailing theory that early humans, particularly Neanderthals, ate meat almost exclusively. But our understanding of paleo human dining changed in 2014 after the discovery of some fossilized human poop in southern Spain, reported in the journal PLOS ONE. The 50,000-year-old coprolite is the oldest-known human feces. Chemical analysis revealed that the donor did eat meat, but also ate his or her share of vegetables.
Evidence of plant consumption has also been found on Neanderthal tools, and even in their calcified dental plaque. In 2017, Australian researchers analyzed dental calculus dating to 50,000 years ago and turned up a variety of carbohydrates and starch granules from plants, but very few lipids or proteins from meat. Neanderthals seemed to be broadly omnivorous, and in some areas, primarily plant eaters.
4. GO AHEAD, GORGE ON GRAINS.
The modern paleo diet forbids all grains, arguing that grain production was a result of the development of agriculture about 12,000 years ago and came after the optimal paleolithic period. The no-grain rule, however, doesn’t reflect the diet of actual paleo humans.
At another ancient site in Israel, Ohalo II on the Sea of Galilee, occupied about 20,000 years ago, researchers found uncultivated wheat and barley alongside an oven-like hearth. The wild grains were harvested with flint blades, processed, and baked. Additionally, analysis of 40,000-year-old dental plaque obtained from human teeth found in Iraq and Belgium indicated the presence of cooked grains.
Both of these discoveries predate the development of agriculture by tens of thousands of years, showing humans living in different places were consuming grains, and perhaps some version of bread, during the Paleolithic era.
5. EAT SWEETS SPARINGLY.
Paleo humans liked the sweet stuff when they could get it, including wild treats like dates and honey. How do we know? Then as now, one of the effects of sugar in one’s diet is the appearance of tooth cavities. In 2015, Italian researchers found the oldest known evidence of dental work in a 14,000-year-old molar, which showed markings from sharp tools used to dig out rotten tissue. Two years later, the same team of scientists discovered the oldest known filling, dating back roughly 13,000 years. An incisor showed a cavity that had been drilled and plugged with bitumen, a semi-solid form of petroleum. Cavities were not thought to be a major part of human experience until after the advent of agriculture, but these paleo chompers suggest otherwise.