Is the Popular 'Paleo Diet' a Bunch of Baloney?
A decade ago, we went crazy for Atkins. Now, a new grain-free, low-carb diet is sweeping the nation. The so-called “Paleolithic” diet – or “paleo” for short – instructs dieters to eat like their Stone Age ancestors ate. The premise of the diet is simple: your body evolved to eat a radically different diet than what most Americans eat today. Go back to that original diet, and you’ll lose weight and eliminate a host of diseases.
Have our bodies evolved to only consume foods found in a hunter-gatherer diet and not from agriculture? And, does the paleo diet, as outlined by the bestselling books by Loren Cordain and Robb Wolf, accurately capture what our cave-dwelling ancestors ate?
The Paleolithic era is defined as the “Old Stone Age.” Roughly speaking, it includes everything from the oldest use of stone tools by human ancestors in Africa up to the dawn of agriculture a mere 10,000 years ago. About 1.8 million years ago, our ancestors experienced a massive increase in brain size. The date humans acquired controlled use of fire is debated, but it likely occurred by about 300,000 years ago at the latest. And, at some point during this long period, our ancestors left Africa and spread throughout the world.
Needless to say, it’s impossible to accurately lump together the diet of every single human ancestor or even just the Homo sapiens who lived in this period. “The truth of the matter is there is no paleo diet,” summarizes Katharine Milton, a professor in the Department of Environmental Science, Policy, and Management at UC-Berkeley. “The only thing you can do is generalize very broadly and you can say beyond a shadow of a doubt that paleo peoples were eating wild plant and animal foods because there was no agriculture and there were no domesticated animals.” A piece in Nature backs her up, showing how difficult it is to reconstruct human diets of the distant past through a variety of means.
Proponents of the paleo diet attempt to distill it into an easy diet plan nonetheless. They tell dieters to eat grassfed meat, seafood, fruits and vegetables, eggs, nuts and seeds, and “healthful” oils (defined as coconut, olive, macadamia nut, avocado, flaxseed, and walnut oils). The list of prohibited foods includes what Cordain calls “Neolithic and industrial-era foods:” all grains, legumes (including peanuts), dairy, refined sugar, potatoes, processed foods, salt, alcohol, and refined vegetable oils.
According to Cordain, “The crucial aspect is to not precisely mimic the exact foods our hunter-gatherer ancestors ate, as this would be impractical or impossible, but rather to mimic the food groups they ate (fresh fruits, vegetables, meat, seafood, poultry, nuts) with commercially available foods from the supermarket.” According to him, “nearly 71 percent of the calories in the typical Western diet come from refined sugars, vegetable oils, cereal grains and dairy products – typically via processed foods. Our hunter-gatherer ancestors from any location on the planet or any time period rarely or never consumed these foods."
How does he know? Logic, he answers. It’s pretty easy to figure out what kinds of food you can’t get when you’ve got no agriculture and little more than stone tools to work with. But, he notes, there are other techniques one can use, including “ethnographic data from historically studied hunter-gatherers,” studying the chemicals in fossilized remains of human ancestors, and finding remains of butchered animal bones or even fossilized human feces.
No matter what, there are several aspects of this diet that deserve praise. Cutting down on sugar, salt, alcohol, and processed foods is a healthy move. So is switching to pasture-raised meat, if you eat animal products. And the oils recommended each provide healthy ratios of omega-6 to omega-3 fatty acids, thus addressing a common problem in the American diet. The diet also preaches variety, telling dieters to switch up what they eat every day, instead of relying on the same handful of foods. These are all concepts that are broadly recommended by many nutrition experts – and they can be adopted without turning back the clock 10,000 years to before the dawn of agriculture.