It goes by a variety of names—the Stone Age, Caveman, Hunter-Gatherer, and Ancient diet. In a nutshell, it’s a modern attempt to replicate the diet of our earliest ancestors. You don’t have to eat exactly the way cavemen did—the key is picking and choosing contemporary foods that are comparable to what people ate back then.
If you’re overweight or you’ve got health problems, adopting a Paleo diet can lead to dramatic improvements. In a Swedish study, researchers asked people to follow either a Paleo or Mediterranean diet for three months. All of the subjects had advanced heart disease, plus either type 2 diabetes or some other form of glucose intolerance. By the end of the study, subjects on the Paleo diet averaged a 26 percent decrease in blood sugar levels, compared with only a 7 percent decrease among those on the Mediterranean diet. Paleo dieters also had an average 2-inch decrease in their waistlines, compared with a 1-inch decrease in the Mediterranean group.
Origins of the Paleo Diet
S. Boyd Eaton, MD, of Emory University, wasn’t the first person to think about the benefits of ancient diets, but he was the first to give it scientific credibility with a 1985 article published in the New England Journal of Medicine. Eaton made the argument that human genes coevolved with their surrounding nutritional environment. In the process, our genes and biochemistry become dependent on the nutrients in fresh, whole foods. Colorado State University’s Loren Cordain, PhD, author of The Paleo Answer, has expanded on Eaton’s work.
Both Eaton and Cordain explain that modern eating habits—heavy on sugar- and carb-rich convenience, fast foods, and junk foods—are incompatible with our genetic heritage. As modern foods clash with our ancient genes, we run a high risk of becoming overweight and developing diabetes, heart disease, cancer, and many other degenerative diseases.
Eaton and Cordain base their research largely on anthropological surveys of 229 different pretechnological hunter-gatherer societies and 50 20th-century hunter-gatherer societies who ate much as their ancient ancestors did. These societies were free of modern diseases, often called the “diseases of civilization.”
Granted, ancient eating habits varied by geography and season. The members of landlocked societies hunted for game, whereas those near the ocean caught seafood. In addition, they all gathered and ate edible plants native to their habitat. The ratio of animal-to-plant foods varied, with some societies consuming more animal foods and others more plant foods. It might come as a surprise that none of the societies was completely vegetarian, according to both Eaton and Cordain.
The Original Organic Diet
In effect, the Paleo diet was the original organic, whole foods diet. Notably absent was the consumption of grains and sugars, with the occasional exception of honey, which was difficult to obtain. Early people didn’t eat bread, muffins, bagels, pasta, pizza, desserts, candy, or soft drinks—no junk foods of any kind.
Our ancestors’ diets began to change around 10,000 years ago with the advent of agriculture and the consumption of large amounts of grain products—including flour, bread, and alcohol. Because human teeth cannot effectively chew hard grains, the seeds had to be pulverized before consumption.
Such processing boosts the glycemic effect of grains, leading to a higher risk of weight gain, diabetes, and heart disease.
There are other problems with wheat as well. In his book Wheat Belly, William Davis, MD, notes that modern wheat is, for all practical purposes, a different plant from ancient wheat, known as einkorn. Einkorn contains only 14 chromosomes (containing genetic material), whereas modern wheat has 42.
Composition of Ancient Diets
Eaton, Cordain, and other advocates of the Paleo diet believe that we can maintain a healthy weight and reduce our risk of disease by eating more like our ancestors. So how does the average Paleo diet stack up to the average American diet today?
- Protein. Animal protein in Paleolithic times provided 19–35 percent of calories, compared with 16 percent today. However, most Paleo meat came from grass-eating animals, so it was relatively lean and comparable to grass-fed beef or venison.
- Plants. Ancient peoples consumed an average of 100 types of vegetables and fruits over the course of a year, providing a diversity of nutrients and antioxidants. Today, most people consume a very narrow range of vegetables, such as small amounts of iceberg lettuce, potatoes, peas, and corn.
- Carbohydrates. Early humans’ carbohydrates came from whole foods, including leaves, roots, nuts, and seeds. Because carbs were part of a fibrous
matrix, only small amounts were actually absorbed. Today, refined high-glycemic carbohydrates (including sugars) account for approximately 80 percent of the calories Americans consume.
- Fiber. Ancient people consumed more than 100 grams of plant fiber daily, compared with an average of less than 20 grams today. According to Eaton, most of the fiber in preagricultural diets came from roots, nuts, and fruits; it did not contain the mineral-inhibiting phytic acid found in grains.
- Grains. As they foraged, ancient peoples likely consumed small amounts of seeds that were the ancestors of modern grains. However, they didn’t consume substantial amounts of grains, which were originally the seeds of wild grasses.
- Fats. Paleolithic humans used no cooking oil, so they consumed only the fats naturally found in meat, fish, and vegetables. This resulted in a relative balance of pro-inflammatory omega-6 and anti-inflammatory omega-3 fats. Today’s grain-fed cattle contain a higher percentage of omega-6 and saturated fats. With the widespread consumption of oils from cereal grains (e.g., corn and soy), the omega-6 to omega-3 ratio is an average of 20:1, which is pro-inflammatory and disease-promoting.
- Dairy. With the exception of infants who were breast-fed, ancient humans did not consume dairy foods. Humans today are the only species on Earth that consumes the milk of other species. Many people are sensitive to casein, one of the proteins in cow’s milk.
- Vitamins and minerals. On average, the amount of vitamins and minerals in ancient diets was several times higher than today’s government recommended amounts. Because foods weren’t processed (other than sometimes being cooked), nutrient density was far higher than in today’s foods.
- Sodium-potassium imbalance. Both minerals are essential for normal heart function. In ancient times, people consumed far more potassium than sodium—roughly 7,000 mg of potassium and 600 mg of sodium daily. The typical American adult now consumes about 4,000 mg of sodium daily, most of which is added during food processing—that is, before food reaches the table. Potassium consumption is lower than in the past, about 3,000 mg daily, mainly because most people eat few vegetables.
- Acid-alkaline balance. The body’s acid-alkaline balance, or pH, affects kidney function and the integrity of bone and muscle. Vegetables and fruits (because of their naturally high content of potassium and bicarbonate) help create a neutral to slightly alkaline body pH, which is healthy. Most other foods create an acidic pH, which leads to the breakdown of bone and muscle to buffer the acidity. Ancient diets contained 35 percent or more plant foods, which Cordain believes helped maintain a normal pH.
The Paleo Payoff
Adopting a modern version of the Paleo diet can lead to rapid improvements in health. Here are some general guidelines, which are relatively easy to follow.
- The Paleo diet is a moderately high protein diet that also contains plenty of fruits and vegetables. In general, you want to eat at least two to three times more vegetables than protein.
- For your protein, emphasize fish, grass-fed meat, and eggs rich in omega-3 fats. For your fruits and vegetables, the keys are fiber and diversity. Eat as many different kinds of vegetables as you can—but avoid or restrict potatoes.
- Limit your intake of grain-based products, particularly wheat, rye, and barley, which contain gluten. Many people are sensitive to gluten, which is also found in many processed vegetarian and vegan foods.
- Minimize your intake of dairy foods because, again, many people are sensitive to them. Although both whey and casein proteins come from dairy, the former is less allergenic.
- A little olive oil and butter are better than grain-based oils such as corn, soybean, and safflower oils. But as a general rule, use as little cooking oil as possible.
- Strictly limit your intake of refined sugars, including most processed foods and beverages.
Like any successful diet, this modern version of ancient eating habits requires some personal discipline. The toughest part for many people may be eating fewer sugary and carb-rich beverages and foods.
Odds are, however, that you’ll begin to see the payoff in just a couple of days—you’ll simply start to feel better. And after several weeks, your blood sugar will likely improve and you’ll see some weight loss.
Jane Barthelemy, author of the new cookbook Paleo Desserts, has perfected the art of gluten-and grain-free baking. “After 20 years of a low-carb diet—all the while still craving sweets—I decided to do something about it,” says Barthelemy, a self-described “ex-sugar-holic.” She discovered that using Paleo-friendly ingredients such as coconut flakes and cacao powder allowed her to enjoy desserts without regret, lethargy, moodiness, and brain fog. Her new book is filled with dessert classics, from Spicy Carrot Ginger Cake with Crème Cheese Frosting to Dutch Apple Pie with Streusel Topping with Whipped Crème. Here, she shares her recipe for Awesome Fudge Brownies, also available in her new book.