The Curious History of the Paleo-Diet, and its Relationship to Science & Modernity

Joseph Knowles emerging from the woods in his "Wilderness Garb," Oct. 4th, 1913

Over the past few years, I've been following the career of a new fad called the "paleo-diet," which advises us to adopt the eating habits of the Pleistocene. I first became aware of it from a New York Times article featuring John Durant, a 20-something office worker turned fitness guru from Manhattan who tries to live as our ancestors did before the dawn of agriculture. On his website, Durant explains that when he started working at his first job out of college, he began to notice that he often felt tired, anxious, and stressed out. He also started to put on weight and noticed that his complexion was becoming uneven.

On the lookout for an explanation for what might be going on with his body, Durant came across the UC Irvine Economist Art de Vany, who had developed a so-called evolutionary fitness regimen. Durant decided to give it a try, and began to eat a diet that is high in fat and protein, as well as fresh fruits and vegetables, but completely avoids grains and all processed foods. Moreover, Durant began to fast for long periods in between meals to simulate the lean times that hunter gatherers often had to endure. Indeed, some advocates of the paleo-diet even go so far as to engage in strenuous exercise before breaking a fast, reasoning that early hominids had to hunt down their prey before consuming a large dose of protein.

There's been a lot of chatter about the relative merits and shortcomings of the paleo-diet recently (including an advice column at the Huffington Post and a hilarious review of Marlene Zuk's book Paleofantasy: What Evolution Really Tells Us About Sex, Diet and How We Live on Salon). I'm not going to evaluate any of the substantive claims made either for or against this lifestyle.  Instead, I want to give a bit of historical context for these discussions from the late 19th and early 20th century (see the image above!).

Most people who have written about the paleo-diet cite a 1985 article in the New England Journal of Medicine entitled "Paleolithic Nutrition — A Consideration of Its Nature and Current Implications" as the point of origin for the fad. In what follows, I'll try to push the narrative considerably further back into recent history. But the NEJM article is worth taking seriously because it makes an important point about not only this fad diet, but indeed every fad diet: they all claim to be grounded in science. What is unique and special about the paleo-diet is that it draws on an unusual branch of science, namely evolutionary theory.

On his website, Art de Vany claims that our evolutionary history did not prepare humans for a modern lifestyle.  To see why one might think this, it is worth taking a detour and listening to an excellent TED Talk that Daniel Dennett gave several years ago.  In his talk, Dennett used a piece of chocolate cake to explain Darwin's curious form of "reverse reasoning." It's not true that we like the chocolate cake because it is sweet, Dennet explains. Rather, it is sweet because we like it.

There is nothing about cake that is inherently sweet. You can stare at a sugar molecule for as long as you want, and you will never understand why it tastes sweet. To understand that, you have to know something about how our brains are wired. And this wiring, Dennett explains, is a product of evolution. Our brains evolved to give us a psychological reward--the taste of sweetness--whenever we eat something that contains sugar, which, of course, is rich in calories. Something similar holds true for fat, salt, and a number of other foodstuffs.

The claim made by proponents of the paleo-diet is that this was good thing during the Pleistocene, because humans did not have access to a lot of calorie-rich foods. To survive and have offspring, you had to consume all the calories available. But in today's world of industrial agriculture and high-fructose corn syrup, that is no longer the case. Differently put: there was no such thing as chocolate cake during the Pleistocene. Probably the sweetest thing anyone would have eaten at that time was a carrot. The chocolate cake is what the ethologist Niko Tinbergen called a super-normal stimulus -- what my own behavioral ecology teacher called "the Dolly Parton effect"--something that is way off the scale of what our bodies have evolved to cope with.

Now, advising people to avoid or at least moderate the consumption of processed foods that are high in salt, fat, and sugar is not in the least bit controversial. I am willing to bet that any conventional nutritionist would be on board with the idea that just because something tastes good does not mean it is good for you, and that we should be careful about simply giving in to all of our cravings. But proponents of the paleo-diet want to go several steps further. Beyond advocating that we avoid foods packed with super-normal stimuli, they also counsel us to avoid dairy, grains, and cereals; indeed, anything that was unavailable prior to the development of agriculture. In so doing, they add an extra ingredient to the evolutionary reverse argument, namely an aversion to modernity.

To see why this is the case, it is useful to extend our historical vision beyond modern-day evolutionists such as Dennett and recent proponents of the paleo-diet like Durant and de Vany. In particular, I want to use the example of Joseph Knowles (pictured above) to show that the paleo-diet is rooted in a much older tradition of what constitutes healthy living.

Joseph Knowles was an artist and illustrator who became famous almost overnight for what he described as an "experiment" that consisted of trying to survive for two months alone in the Maine wilderness. His fifteen minuts began when reporters from the Boston Post photographed him gingerly disrobing, discarding his knife and other accoutrements of modern life, demonstrating his ability to make fire by rubbing pieces of wood against one another, and entering the woods, all on the morning of August 10, 1913.

Joseph Knowles demonstrating his wilderness survival skills just before heading off into the forest, August 10th, 1913.

During the two months he allegedly spent in the wilderness, Knowles periodically sent updates about his adventures to the Post, written in charcoal on a piece of tree bark.  Among other things, he recounted spending the first few days subsisting on berries before learning how to fish trout and hunt partridge and deer. He also wove strips of tree bark together to create a kind of textile that he could fashion into clothing and shoes. Then, on August 24th, about two weeks after he entered the forest, a front page story in the Post described how Knowles had successfully killed a bear using nothing but his wits and a club.

When he emerged from the wilderness wearing the bearskin on October 4th, Knowles received a hero's welcome. He was cheered on at every stop of the way from Maine down to Boston, and huge crowds gathered to see him arrive at North Station before he gave a rousing speech about his experiences in the Boton Common. In the months that followed, Knowles wrote a best-selling book about his adventures entitled Alone in the Wilderness and received top billing on the Vaudeville circuit.

There's lots to be said about Joseph Knowles, including the fact that a rival newspaper published evidence to the effect that he had spent most of his time in the "wilderness" drinking beer in a friend's cabin. But I want to focus on one piece of the story in particular. One of the first things Knowles did after arriving in Boston was to pay a visit to Dudley Allen Sargent, the Director of the Hemenway Gymnasium at Harvard University.

Dudley Sargent examines Joseph Knowles at Harvard's Hemenway Gymnasium.

In his autobiographical account of the saga, Knowles quoted Sargent as attesting to the fact that his time in the wilderness had left him in better shape than any of the college's "football men," reporting, among other things, that "With his legs alone he lifted more than a thousand pounds." Sargent also noted a remarkable improvement in Knowles' complexion: "Subjected to the action and the stimulus of the elements, Mr. Knowles' skin has [come to serve] him as an overcoat, because it is so healthful that its pores close and shield him from drafts and sudden chills." Thus, Sargent declared the "experiment" a complete success. "Forced to eat roots and bark at times, and to get whatever he could eat at irregular hours, his digestion is perfect, his health superb."

Along with this testimonial, Knowles also included a chart comparing some of his vital statistics from before and after the time that he spent in the wilderness. Not only had he lost more than ten pounds, but, remarkably, he had grown slightly taller as well. Moreover, his muscles all increased in size and in girth, and his lung capacity shot up from 245 cubic inches to an astonishing 290 cubic inches!

Joseph Knowles' vital statistics before and after the wilderness "experiment."

As historians of science and environmental historians well known, Joseph Knowles was part of a larger cultural movement that Roderick Nash's classic account describes as a kind of "wilderness cult." Other notable examples of this movement's popularity include the founding of the Boone and Crockett Club in 1887, the Sierra Club in 1892, the Boy Scouts of America in 1910, as well as Theodore Roosevelt's fierce advocacy on behalf of wilderness preserves such as Yellowstone National Park as a place in which white, urban elites could experience what he called the "strenuous life."

It is no surprise that the wilderness cult took off when it did. At a time in which America was becoming increasingly urban, industrial, and ethnically diverse, many worried that rather than heading for increasing prosperity, the country was inevitably on the decline. Thus, it seemed natural to harken back to a simpler and more authentic past, one in which people's communion with nature left them healthier in body, mind, and soul. It was, after all, during this period that the historian Frederick Jackson Turner used a podium at the 1893 Chicago World's Fair--a celebration devoted to industrial progress in a city that did more than any other to conquer the west--as a platform from which to mourn the official closing of the nation's western frontier. And it was also during this period that Madison Grant, director of the Bronx Zoo and Trustee of the American Museum of Natural History, published his eugenic masterpiece, The Passing of the Great Race. Envisioning a dark future indeed, Grant counseled his readers to eschew the comforts and luxuries of modern civilization and allow the Darwinian struggle to continue tending the health of the gene pool.

Few things sum up these sentiments as well as the first edition of Ernest Seton's Handbook for the Boy Scouts of America. "We have lived to see an unfortunate change," he lamented on the very first page of the Handbook. "Partly through the growth of immense cities," and "[p]artly through the decay of small farming," he continued, America entered a period that Seton and so many others described using the word "Degeneracy."  Thus, it was to "combat a system that has turned such a large proportion of our robust, manly, self-reliant boyhood into a lot of flat-chested cigarette smokers, with shaky nerves and doubtful vitality" that he brought scouting to America. Mindful of the fact that "Consumption" had become "the white man's plague," he concluded, "I should like to lead this whole nation into the way of living outdoors for at least a month each year."

In closing, let me forestall a possible misinterpretation. Of course I do not mean to imply that Durant and other advocates of the paleo-diet are all eugenicists at heart. That is certainly not the lesson I hope people take away from the history that I have tried to present. But I do think that a few striking and salient parallels present themselves.

Perhaps it is a cliche to say that we are living through a time of enormous change, just as people during the American Gilded Age and Progressive Era did, but that does not make it any less true. One thing that I would like to suggest we are seeing, not just in the paleo-diet, but certainly there as well, is a kind of aversion towards modernity. People now as well as a hundred years ago have looked and are looking to the past in search of a simpler, more authentic, and, importantly, more healthful way to live one's life.

But what is so curious about all of this is that so many of these people--from Joseph Knowles to Art de Vany--are also looking to science, a quintessentially modern institution if there ever was one, for both advice on how to get there as well as for the authority to argue that an earlier period in human history really was healthier and more adapted to our physical, spiritual, and emotional needs.