So far studies of foragers like the Tsimane, Arctic Inuit, and Hadza have found that these peoples

 So far studies of foragers like the Tsimane, Arctic Inuit, and Hadza have found that these peoples

 traditionally didn’t develop high blood pressure, atherosclerosis, or cardiovascular disease. “A lot of people believe there is a discordance between what we eat today and what our ancestors evolved to eat,” says paleoanthropologist Peter Ungar of the University of Arkansas. The notion that we’re trapped in Stone Age bodies in a fast-food world is driving the current craze for Paleolithic diets. The popularity of these so-called caveman or Stone Age diets is based on the idea that modern humans evolved to eat the way hunter-gatherers did during the Paleolithic—the period from about 2.6 million years ago to the start of the agricultural revolution—and that our genes haven’t had enough time to adapt to farmed foods.

A Stone Age diet “is the one and only diet that ideally fits our genetic makeup,” writes Loren Cordain, an evolutionary nutritionist at Colorado State University, in his book The Paleo Diet: Lose Weight and Get Healthy by Eating the Foods You Were Designed to Eat. After studying the diets of living hunter-gatherers and concluding that 73 percent of these societies derived more than half their calories from meat, Cordain came up with his own Paleo prescription: Eat plenty of lean meat and fish but not dairy products, beans, or cereal grains—foods introduced into our diet after the invention of cooking and agriculture. Paleo-diet advocates like Cordain say that if we stick to the foods our hunter-gatherer ancestors once ate, we can avoid the diseases of civilization, such as heart disease, high blood pressure, diabetes, cancer, even acne.

That sounds appealing. But is it true that we all evolved to eat a meat-centric diet? Both paleontologists studying the fossils of our ancestors and anthropologists documenting the diets of indigenous people today say the picture is a bit more complicated. The popular embrace of a Paleo diet, Ungar and others point out, is based on a stew of misconceptions.

The Hadza of Tanzania are the world’s last full-time hunter-gatherers. They live on what they find: game, honey, and plants,