Read an Excerpt
Becoming the Caveman
What would it look like if a caveman were interviewed on TV? America was about to find out. On February 3, 2010, I was backstage at The Colbert Report, waiting to be interviewed by the razor-sharp comedian. Colbert's interviews are among the most difficult on television--and it was going to be my first ever TV appearance.
Colbert had invited me on because of my so-called caveman diet. Admittedly, my health regimen sounds unusual at first. I attempt to mimic aspects of life during the Stone Age--or, as many people jokingly refer to it, "living like a caveman." Heck, I even look the part, with a shaggy mane and scruffy beard.
In popular culture the "caveman in civilization" is a reliable source of punch lines. In 2004 GEICO ran an award-winning series of commercials showing a pair of well-dressed cavemen offended at the insurance company's tagline, "So easy a caveman can do it." On Saturday Night Live in the mid-nineties, Phil Hartman played Unfrozen Caveman Lawyer, a thawed Neanderthal who enrolled in law school and won over juries by pretending to be a simpleton ("Ladies and gentlemen of the jury, I'm just a caveman!") before delivering the clinching argument.
The jokes begin as soon as people find out about my lifestyle. Whenever I use a piece of modern technology (a cell phone, a Styrofoam cup, a spoon), someone reminds me, "Cavemen didn't use those!" People tease me about the caveman approach to dating: clubbing a girl over the head and dragging her by the hair back to my apartment. And if I ever eat anything other than raw meat straight off the bone, my co-workers kindly inform me that I am doing it all wrong. Apparently, watching reruns of The Flintstones turns anyone into an expert paleoanthropologist.
Given the widely held cartoonish perspective of Stone Age life, I had a pretty good idea of what kind of jokes to expect from Colbert. My job was to point out that our impression of how humans lived in the Stone Age is exactly that: a cartoon. In the same way that Mickey and Minnie Mouse tell us little about the lives of real mice, The Flintstones tells us little about the lives of real Stone Age humans. In fact, the terms "caveman" and "Stone Age" are inaccurate and outdated. Though some early humans lived in caves, particularly in cold or mountainous climates such as Europe, our Paleolithic ancestors lived for millions of years underneath the big open sky of the African savannah.
These early humans were hunter-gatherers who foraged for a variety of wild foods, and whose lifestyle was quite different from the lives people lead today. This ancient, ancestral lifestyle is more important than we realize--especially when it comes to being healthy in the modern world.
Here's the simple truth: genetically speaking, we're all hunter-gatherers.
Of course, we're not just hunter-gatherers. We also carry the genes of primates; herders and farmers; factory workers and explorers; office workers and computer programmers. But at our biological core we are still largely hunters and gatherers.
My path to discovering my inner hunter-gatherer began during my junior year at college. Two important but seemingly unrelated events took place at the same time. First, I went through a long breakup with a girlfriend and watched my physical and mental health suffer. Second, I began studying under cognitive psychologist Dr. Steven Pinker, learning about the evolution of the human mind over millions of years and how that evolutionary history shapes the way our minds work today.
In the middle of the breakup I had an epiphany: If I got fewer than eight hours of sleep, it felt like my world was coming to an end. But on the days when I got more than eight hours of sleep (and exercised), I was able to put it all behind me. It blew my mind that my entire outlook on a relationship could be so noticeably influenced by my bedtime. Rather than having a mind or spirit that rose above my base body, it seemed like I was nothing more than a bunch of cells and chemicals sloshing around in a big, leaky sack.
As the geneticist Theodosius Dobzhansky said, "Nothing in biology makes sense except in the light of evolution." Pinker's course on evolutionary biology examined the capacities of the human mind through the lens of the survival and reproductive pressures faced by our ancestors. It addressed questions like "Why do many people have a visceral fear of snakes, which kill only a few people each year, but not of automobiles, which kill tens of thousands of people each year?"
Evolutionary theory points out that snakes were a real and deadly threat to our ancestors--but automobiles were not. Our ancestors with an innate fear of snakes would have been less likely to risk a deadly encounter with one, and thus would have been more likely to produce more offspring. This hypothesis wasn't just an after the fact rationalization of a fear. The fear of snakes is widespread among other primates, which share similar predators. The same line of thinking can be used to explain a variety of common fears that were past evolutionary threats, such as darkness, deep water, and heights. The power of the human mind is such that instinctual fears can be overcome (and novel fears can be imprinted), but the predisposition still looms in our minds.
Evolutionary psychology can also explain some of our moral intuitions. For example, why is there an almost universal aversion to incest? Inbreeding is far more likely to result in birth defects; just ask the owner of a purebred dog. In our evolutionary past, people with an aversion to having sex with their close kin would have been more likely to produce fertile and healthy offspring. Cultural norms almost always reinforced this instinctual aversion to incest, even though people may not have understood why the norms existed. They just worked, and the people who held such norms ended up flourishing.
This newfound perspective redirected my entire course of study halfway through college. I shifted away from my major, history, and toward evolutionary psychology, culminating in an interdisciplinary thesis advised by Pinker. I wanted to explore mankind's murky origins--and their lingering effects on us today.
Then I graduated. I moved to the urban jungle and joined the daily grind. Abstract ideas about cavemen gave way to the concrete reality of paying the rent on a cave-like apartment in New York City.
I worked long hours, including weekends, at a consulting firm. My company would buy takeout when I worked late, which meant I ate takeout almost every night. I sat most of the day and rarely found time to exercise. I didn't sleep enough, and when I had the opportunity I usually went out drinking with friends. "Work hard, play hard" meant being hard on my health all the time.
Like most others starting their first desk job, I found that my metabolism seemed to slow down in a big way. I gained about twenty pounds of solid fat. This actually didn't bother me that much. I had been lean before, and now I was "normal" (meaning, kind of hefty). To me the more important issue was my energy level: It was up and down. I often couldn't even stay awake, let alone function productively, without large amounts of caffeine.
Just like during that breakup, as my energy went, so went my mood. Low energy meant pessimism, impatience, irritability. High energy meant optimism, confidence, and an upbeat perspective. My outlook, my judgment, my decisions--things that were central to who I was as a person--seemed to be influenced by something as simple as what I had eaten for lunch (often a footlong Subway meatball sub) and whether I had made a Starbucks run.
I don't know why it took me so long to make the connection--it certainly wasn't a lack of coffee--but one day I considered the situation in a new light. Could I take control of my health and diet in order to improve my mood and outlook? Could I be "up" all the time?
I began where most people who want to get healthier begin: my diet. Maybe, as so many nutritionists advise, I needed to nibble on lots of small snacks throughout the day to keep my blood sugar up. Or maybe my metabolism was just naturally slowing down due to age. Or maybe I was eating too much fat or too many calories. Or maybe I was supposed to eat organic. Regardless, I knew I had to eat healthier--which is what most people would call "going on a diet." But I had never been on a diet in my life.
As any rugged man age eighteen to thirty-five can tell you, diets are for women and organic food is for hippies. The only time I had ever counted calories in a meal was to brag about how many I had just eaten. If I was weighing myself, it was probably because I wanted to gain weight (i.e., muscle). It's not as if the diet industry had a great track record of success. From an outsider's perspective, it seemed like a constant churn of celebrity-endorsed double-talk that gets renamed, repackaged, and resold to desperate women straight out of a Cathy cartoon. Ack!
I needed a scientific framework that worked and made sense. I needed something that had the power to explain why.
That "something" popped into my inbox at 4:01 P.M. on February 14, 2006. It came attached to an email from my older brother Clark, who sent me a twenty-six-page essay by Dr. Art De Vany, a retired economist from the University of California. De Vany titled his essay "Evolutionary Fitness." The title was an academic pun: it referred to "fitness" in the common definition of exercise, as well as "fitness" in the evolutionary biology sense of reproductive fitness, meaning an organism's overall ability to leave offspring.
The essay was based on a simple premise: There is a mismatch between our genes and the lives that we lead today.
Humans aren't adapted to sitting at desks all day long, eating Twinkies and drinking Pepsi. Humanity spent most of its evolutionary existence living as hunter-gatherers on the African savannah; therefore humanity was better adapted to that type of lifestyle. Many modern health problems, such as obesity, diabetes, heart disease, and cancer, are rare to nonexistent among contemporary hunter-gatherers. Our hunter-gatherer ancestors were healthier and lived longer than most people realize. If we wanted to be healthy, then we might be able to learn a thing or two from them.
Old knowledge didn't need to be wrong knowledge.
The general mismatch hypothesis wasn't original to De Vany. A wide variety of academics and authors had written about a disconnect between our ancestral lifestyles and our current ones, but in the age-old scientific tradition of self-experimentation, De Vany was one of the first to take it out of the classroom, apply it to his own diet and exercise, and then share his experience with others online.
Because I had studied evolutionary psychology, the general evolutionary approach to health immediately struck a chord with me. Instead of reading a diet book to learn about what to eat, I could find out what humans naturally ate. Lions are well adapted to a carnivorous diet. Gorillas are well adapted to an herbivorous diet. Humans are well adapted to an omnivorous diet, based on the foods eaten by hunter-gatherers.
Online I discovered a small but growing group of people who were "eating paleo," and, more broadly, following a paleo lifestyle. But what did that actually mean?
Not only did eating paleo imply avoiding processed foods, as most conventional health authorities recommend, but it also meant casting a skeptical eye on allegedly "healthy" agricultural foods like whole grains and legumes (wheat, corn, soy) and dairy (milk, yogurt, cheese), which didn't enter the human diet in any meaningful amount until the Agricultural Revolution roughly 10,000 years ago. Also suspect were two common approaches to healthy eating--low fat and vegetarianism--since humans have been eating animals for millions of years.
As for exercise, other animals don't "exercise" so much as they either play or just do what is required to survive. Birds fly. Fish swim. Humans are well adapted to moving in our own natural ways: ranging across the savannah, hunting, gathering, fighting, and procreating.
Modern humans are more sedentary than ever, and the evolutionary perspective agreed with the modern conventional wisdom. Want to be healthier? Move more. Yet many people exercise in highly routinized and monotonous ways, like running on a treadmill in a gym. They focus on abstract goals, like burning calories, and lose sight of functional, goal-oriented movements such as sprinting away from a threat or carrying an animal carcass back to camp. At a minimum, the evolutionary approach implied injecting variety into the types of movements and intensity level; hunter-gatherers did not do the elliptical for thirty minutes a day, four days a week. But there were limits to this line of thinking. The hunter-gatherer's source of motivation was running from a lion; the closest modern analogue is chasing down a cab--and no matter what we tell ourselves, there's hardly the same sense of urgency.
There were specifics to fill in, but the general evolutionary approach was sound. It was the appropriate starting point for any intelligent discussion on how to be healthy--even if it wasn't the last word.
Theories are nice, but would it work? Things were going to get real Darwinian real fast.
I started eating paleo in September of 2006.*
I stopped eating industrial foods: no ketchup, mac and cheese, mozzarella sticks, or sweets. I stopped eating grain products like wheat, corn, and rice; legumes like soy, peanuts, and beans; and dairy. I also eliminated starchy foods like potatoes (though I would come to learn that roots and tubers are a staple in many hunter-gatherer diets, both Paleolithic and contemporary).
Surprisingly (to me), there was still a wide range of foods available to eat. My status as an "omnivore" was not in question. I ate meat, seafood, fresh vegetables, and a modest amount of fruit, nuts, seeds, and eggs--basically any category of food that seemed like it would have been available in the wild that also happened to be available in my local grocery store (except for my prejudice against potatoes).
I moved away from "three square meals a day" and interjected a little variation into my eating routines. I even fasted once a week for the first three months, skipping dinner and going roughly eighteen hours from lunch to the following breakfast.
I never counted calories or measured macronutrients (fat, protein, and carbs). Relative to what is considered "normal," I ended up with a high-fat, moderate protein, low-carbohydrate diet.
I found it hard to give up alcohol entirely, but I completely cut out sweet mixers and cut back on beer, which is grain-based. I reduced my coffee intake to about a cup a day, only in the morning.
I did my best to get at least seven hours of sleep at night, and I got more sunshine during the day.
After about ten days of eating paleo, I knew I had something. My "diet" was working.
* My current diet has "evolved" from my initial experiment at eating paleo. A longer discourse on food can be found in Chapters 7 and 8, and a summary is located in Recommendations.