I first heard of the paleo diet about four years from a coworker who was following it at the time. When he explained the diet guidelines to me, my first reaction was a mixture of amazement and horror – no bread? No peanut butter? No cheese? How could a person just give up, in my opinion, all of the most delicious types of food? With that question in mind, here is an overview of the possible positive and negative impacts of the now-popular paleo diet.
History of the Paleo Diet
The idea of the Paleolithic, or paleo, diet partly stems from former University of California – Irvine Economics Professor Arthur De Vany. For the past 25 years, Professor De Vany has advocated an “evolutionary fitness” regimen, which combines a high-protein/low-carb diet with interval or cross-training sessions and periodic fasting. This overall regimen is meant to mimic the nomadic lifestyle that our hunter-gatherer ancestors followed before the rise of agriculture about 10,000 years ago.1 However, this idea of returning to a hunter-gatherer lifestyle extends decades back.
On August 10, 1913, artist and illustrator Joseph Knowles began his two-month-long wilderness trip in Maine. The Boston Post tracked Knowles’ feat. Knowles reported eating just berries for the first few days before he learned how to fish for trout and hunt deer. He wove tree bark strips together to create clothes, and he killed a bear with only a club he had fashioned for himself in the woods. On October 4th, 1913, he returned to Boston wearing the bearskin and received a huge welcome. Knowles later wrote a memoir titled Alone in the Wilderness, which became a best seller. Interestingly, he had kept track of his vital statistics, such as weight, lung capacity, etc., before and after his two-month experiment and found, for example, that he had lost 11 pounds and that his lung capacity had increased from 245 cubic inches to 290 cubic inches. Dudley Allen Sargent, the Director of Hemenway Gymnasium at Harvard University, complimented Knowles’ on his newfound strength and healthy complexion and digestion. Knowles’ actions were part of a larger cultural movement at the time that embraced the wilderness as a source of strength while America became increasingly urban and industrial.2
Fast forward to 1985, when S. Boyd Eaton and Melvin Konner published “Paleolithic Nutrition – A Consideration of Its Nature and Current Implications” in The New England Journal of Medicine.3 This article brought the paleo diet to the attention of the public and explored the diet’s use of evolutionary science. Finally, in 2011, after De Vany published The New Evolution Diet, this “eat like a caveman” concept really took off.4
Paleo Diet Guidelines
What you can eat:5
- iiLean meat (chicken, turkey, pork, beef, bison)
- Seafood
- Fruit
- Non-starchy vegetables (spinach, asparagus, broccoli, etc.)
- Nuts (almonds, walnuts, cashews, etc.)
- Seeds (pumpkin, sunflower, etc.)
- Eggs
- Plant-based oils (olive, coconut, etc.)
What you cannot eat:6
- Grains (oats, wheat, barley, rice)
- Starchy vegetables (potatoes, corn, etc.)
- Legumes and beans (peanuts, soy, hummus, black beans, baked beans)
- Dairy products (milk, yogurt, cheese, ice cream, etc.)
- High-fat meats (salami, pepperoni, hot dogs, ribs, etc.)
- Sugar (soda, honey, jam, syrup, candy, cake, cookies, sports drinks)
- Processed food and trans fats (doughnuts, French fries, fruit snacks, mac and cheese, etc.)
- Salty food (crackers, chips, pretzels, etc.)
Note: There are no specified portions for the allowed foods.
Benefits of the Paleo Diet
Given the current state of the , there are some indisputable health benefits to the paleo approach. First, our Paleolithic ancestors consumed three times more produce, more fiber, protein, omega-3 fatty acids, unsaturated fat, vitamins, minerals, and less saturated fat and sodium than the average American does today. Since many of our diets’ today are heavily reliant on grains and starchy vegetables, we could certainly use an emphasis on fruits, vegetables, and lean protein. This emphasis also helps one avoid the processed, pre-packaged foods that are designed to sit on grocery store aisles for months.7 As De Vany says, “[j]ust because you can eat it doesn’t mean it’s food.”8 In addition to avoiding additives and preservatives, the paleo diet has anti-inflammatory effects from the nutrients found in the allowed fruits, vegetables, oils, nuts, and seeds. Paleo dieters have also noted that they feel more satisfied and full between meals because of the increased intake of protein and fat. Another benefit is that this satiation combined with the elimination of processed foods leads to weight loss for many paleo dieters.9
Negative Aspect of the Paleo Diet
There are certainly drawbacks to this lifestyle approach. First, the paleo diet’s emphasis on protein makes it very costly and not necessarily accessible to the masses. Second, your body may experience a nutrient imbalance if you take away certain foods, such as dairy products, and do not find suitable replacements for them. Third, vegetarians will find following this diet extremely difficult due to its emphasis on meat and its bean and legume ban.10
Science Behind the Paleo Diet
There is a good deal of dispute surrounding the evolutionary science that the paleo diet is supposedly based upon. First, it is worth pointing out that our hunter-gatherer ancestors faced many health problems themselves, such as parasites, infectious disease, and atherosclerosis, which is the hardening of the arteries.11 Second, there was no universal Paleolithic lifestyle because people during that time period already lived in vastly different climates, prompting different diets, behaviors, and genetic adaptations. Many disagree with De Vany’s claim that a baby born 40,000 years ago is genetically the same as baby born today—human genetics have been continuously evolving since 40,000 years ago, especially since the birth of agriculture around 8,000 B.C.E.12
The paleo approach to exercise, which encourages short, cardiovascular bursts in order to mimic hunting, has also been criticized for being historically inaccurate. Daniel Lieberman, a human evolutionary biologist at Harvard University, states that the human ability to run long distances and produce sweat were adaptations key to survival during those times. Unlike De Vany claims, Paleolithic hunters did not quickly attack their prey but rather used a model called persistence hunting, in which they may have run for up to 9 miles per day following their prey until it collapsed from overheating.13 Furthermore, it is likely that the gatherers walked around 6 miles per day collecting food. For these reasons, Lieberman asserts that a human 40,000 years ago would have actually been a great endurance runner but a terrible sprinter.14
Whether or not you agree with the full paleo lifestyle, certain facets of the diet, such as choosing fresh fruits, vegetables, and lean protein over processed foods, are definitely worth adopting. Perhaps it is even easier than it sounds once you really get going?!
