According to Paleo devotees, the human diet began deteriorating during the Agricultural Revolution 10,000 years ago when we started eating farm-raised grains in large quantities. Then, 200 years ago, the Industrial Revolution led to processed, packaged foods laden with additives and preservatives, resulting in our current obesity epidemic.
Dr. Loren Cordain, father of the Paleo movement, advocates a meat-centric diet that supposedly is based on the diet of ancient societies. According to his studies, the typical Paleolithic tribe’s diet was comprised of roughly 56 to 65 percent meat. A paper published in the New England Journal of Medicine in 1985 suggested the ratio could even be higher. However, many anthropologists say some older Paleolithic studies that contributed to the “meat-centric” caveman image were skewed by the fact that bone is far better preserved at archaeological sites than biodegradable vegetable matter.
While meat played a critical role in human evolution, most anthropologists today have largely rejected the myth of blood-thirsty carnivorous cavemen. Instead, primitive human beings were opportunistic omnivores—with teeth, limbs, and a gastrointestinal tract more conducive for digesting plant material than large quantities of meat. Gathering wild plants required much less caloric expenditure than hunting, and yielded more reliable sustenance. While meat consumption varied by geographic location, anthropologists at Washington University in St. Louis estimate that meat comprised less than 20 percent of most paleolithic diets.
Berries, nuts, and even wild grains comprised the bulk of the diet for many Paleolithic tribes, according to Dr. Anna Revedin at the Italian Institute of Prehistory. Researchers found evidence on 30,000 year-old grindstones found throughout Europe that suggests Paleos harvested plants like cattails and fern roots to make flour. Meanwhile, grains have been found in Paleolithic storage bins, and a 2004 study of a Stone Age site in Israel showed the staple food was wild grasses.
Rebecca Mohning, a registered dietician who teaches at George Washington University, puts the Paleo Diet in the same “fad” classification as the Atkins diet, though she believes Paleo is more balanced than its predecessor.
“The Paleo Diet’s emphasis on fresh, seasonal produce and minimally processed foods is commendable, but I don’t recommend a diet that cuts back on whole grains,” she says. “Carbohydrates are the body’s essential fuel, especially for athletes.”
A growing number of fitness professionals warn endurance athletes from adopting such a severe nutritional approach.
“Your body needs carbs to function. Endurance athletes need them even more,” says Colin Izzard, head coach at Carmichael Training in Asheville, N.C. “If you don’t replace them during activity and after, you bonk. In the long term, your body will begin to break down. The strict Paleo Diet won’t work for endurance athletes. Can you imagine how many apples you’d have to eat for a 3,000-calorie bike ride?”
Even Paleo founding father Loren Cordain acknowledges the need for carbs in endurance athletes. His latest Paleo book, The Paleo Diet for Athletes, recommends incorporating carbs like sweet potatoes into an athlete’s workout cycles, then pairing down on the carbs during rest periods. It’s a more balanced approach to nutrition that takes the individual into account.
“I have to modify the Paleo Diet when I’m training for a race,” says Erin Kelly Ferner, a Paleo practitioner dietician, and endurance athlete. “Nutrition is extremely individualized. The Paleo Diet, like any other nutrition plan, is about trial and error. You have to play with it and see what works for you.”
While meat remains a bone of contention, Paleo critics and advocates agree that seasonal fruits and vegetables are essential components of a healthy diet, both then and now. Also universally celebrated is the Paleo Diet’s emphasis on eliminating refined sugars, preservatives, and processed foods. Over one-third of America’s diet today consists of junk food, soft drinks, sweets, alcohol, and salty snacks.
“Look at the diet objectively, and most of it is just common sense healthy eating,” Izzard says. “It’s nothing new. It’s just packaged differently.”