Our Human Ancestors Were Vegetarian

Artificial colors. Artificial flavors. Artificial sweeteners. High fructose this. Partially hydrogenated that. Few would argue that the “food products” found on most grocery store shelves these days are anything close to natural.

In fact, most of these products didn’t even exist just a few decades ago. Take high fructose corn syrup, for example. Hard to believe, but the now-ubiquitous HFCS only went mainstream about 30 years ago.


A few decades can seem like an eternity in the context of a human life, but it’s a blink of an eye on the scale of the Earth’s history and timeline. So it’s no wonder many people worry about the impacts of our rapidly-changing diets on our slowly evolving bodies. And this concern has predictably led to…you guessed it, new diet books!

“Paleolithic diets have become all the rage, but they are getting our ancestral diet all wrong,” notes biologist and writer Rob Dunn in a recent piece for Scientific American.

So-called Paleolithic diets are an attempt to mimic the eating style of Paleolithic man. If you couldn’t hunt it or gather it you couldn’t eat it. There was no agriculture – plant or animal – no processed foods, no grains, and no shipping in bananas from Central America. These diets are typically classified as “low carb” and emphasize meat, fish, nuts and seeds, and certain fruits and vegetables.

While researchers disagree about the prominence of meat in the diet of Paleo man, Dunn aptly points out that it may not actually matter. He explains:


“…if we want to return to the diet our guts and bodies evolved to deal with, we should not be looking at our most recent ancestors. Instead, we need to understand the diet of our ancestors during the time when the main features of our guts, and their magical abilities to turn food into life, evolved. We need, in other words, to look at apes, monkeys and other non-human primates.”

He also points out that the digestive systems of modern man are remarkably similar to those of gorillas, chimpanzees, monkeys, and apes. And their diets consist mainly of fruit, nuts, leaves, and insects, and the occasional bird or lizard. Overall, however, meat makes up less than three percent of their dietary intake.


Thus, this dietary composition mimics the way our ancestors spent the most time eating during the largest periods of the evolution of our guts. And it hardly sounds low carb.

So what should we be eating? Dunn quips about giant sloths, mastadons, insects, and even feces. But fruit, nuts, seeds and greens sound like a pretty solid base. Throwing in a few foods your ancestors wouldn’t recognize probably won’t kill you, but they shouldn’t be staples in your diet.

Image Credit: Scientific American