The paleolithic diet (abbreviated paleo diet or paleodiet), also popularly referred to as the caveman diet, Stone Age diet and hunter-gatherer diet, is a modern nutritional plan based on the presumed ancient diet of wild plants and animals that various hominid species habitually consumed during the Paleolithic era—a period of about 2.5 million years which ended around 10,000 years ago with the development of agriculture and grain-based diets. In common usage, such terms as the “Paleolithic diet” also refer to the actual ancestral human diet.
Centered on commonly available modern foods, the “contemporary” Paleolithic diet consists mainly of fish, grass-fed pasture raised meats, eggs, vegetables, fruit, fungi, roots, and nuts, and excludes grains, legumes, dairy products, potatoes, refined salt, refined sugar, and processed oils.
First popularized in the mid-1970s by gastroenterologist Walter L. Voegtlin, this nutritional concept has been promoted and adapted by a number of authors and researchers in several books and academic journals. A common theme in evolutionary medicine, Paleolithic nutrition is based on the premise that modern humans are genetically adapted to the diet of their Paleolithic ancestors and that human genetics have scarcely changed since the dawn of agriculture, and therefore that an ideal diet for human health and well-being is one that resembles this ancestral diet. Proponents of this diet argue that modern human populations subsisting on traditional diets allegedly similar to those of Paleolithic hunter-gatherers are largely free of diseases of affluence, and that multiple studies of the Paleolithic diet in humans have shown improved health outcomes relative to other widely recommended diets. Supporters also point to several potentially therapeutic nutritional characteristics of preagricultural diets.
Eating like our ancient ancestors, is healthy says Professor Loren Cordain, author of The Paleo Diet. He says: “Clinical trials have shown that the Paleo diet is the optimum diet that can lower the risk of cardiovascular disease, blood pressure, markers of inflammation, help with weight loss, reduce acne and promote optimum health and athletic performance.”
Supporters of this nutritional approach have published papers and books and created web sites, to promote it. They argue that today’s typical Western diet is responsible for the epidemic levels of obesity, heart disease, diabetes and other health problems.
The Paleo or Caveman diet is not without controversy. Some nutrition experts assert that humans have adapted to a broader diet, including whole grains, dairy products and legumes. Others question the evidence for the diet’s evolutionary logic.
Even though grains and dairy seem healthy, Professor Cordain says our “genome has not really adapted to these foods, which can cause inflammation at the cellular level and promote disease”.
The Caveman diet: What you can eat
The diet is based on the foods that could be hunted, fished and gathered during the Paleolithic era – meat, fish, shellfish, eggs, tree nuts, vegetables, roots, fruits and berries.
However, a true paleolithic diet is impossible to mimic because wild game is not readily available and most modern plant food is cultivated rather than wild and meats are domesticated.
At best, you can eat a modified version of the original diet that’s gluten-free and includes lean meat, organ meats, fish, poultry, eggs, vegetables, fruit and nuts.
You won’t find any dairy, grains, sugar, legumes, potatoes, processed oils or any foods that were grown after agriculture started.
On this diet you’d skip salt and any drinks other than water, coconut water or organic green tea.
You can satisfy your sweet tooth with raw honey or coconut palm sugar, but only in limited quantities.
Some versions of the plan encourage fasting, eating raw foods and eliminating “nightshade” vegetables (tomatoes, aubergine).
Some plans allow a little flexibility, like adding some processed oils from fruits and nuts, such as olive and flaxseed oil.
Supporters suggest eating organic plant foods, wild-caught fish and grass-fed meats because they’re closer to the nutritional quality of the foods of our ancestors.
The Caveman diet: How it works
Supporters of the Paleo diet say people are genetically programmed to eat like cavemen did before the agricultural revolution. They also say it’s a way to cut the spiralling cases of obesity, diabetes, heart disease and other chronic conditions.
That’s because a diet rich in lean protein and plant foods contains fibre, protein and fluids that work together to satisfy, control blood sugar and prevent weight gain and type 2 diabetes.
You may not need to eat this way all the time. According to Professor Cordain, eating like our ancestors 80% of the time offers health benefits. He suggests trying the diet for two weeks to see if you feel better on the plan.
The plan also encourages people to be physically active on a regular basis. After all, hunter-gathers had active daily lives seeking food, water and shelter.
The Caveman diet: Experts’ views
Nutrition experts have been clamouring for years for a cleaner diet based on whole foods, lean meats, fruits, vegetables and less sugar, sodium and processed foods.
However, they also typically include low-fat dairy, legumes and whole grains, based on the wealth of research that supports the role of these foods in a healthy, well-balanced diet.
Dr Áine O’Connor, nutrition scientist with the British Nutrition Foundation tells us: “The Paleo or paleolithic diet has some positive aspects in that lean meats, fruits, vegetables and foods containing less sugar and salt are encouraged, but it has limitations, namely by excluding certain food groups such as milk and dairy foods, which can lead to nutrient deficiencies in the long term.
“Overall, the Paleo diet is not sustainable due to lack of variety and the potential for nutrient deficiencies.”
The British Dietetic Association refers to the Caveman diet as a fad diet. It says it comes in several variations but, in general, is based on eating one main meal per day between the hours of five and seven in the evening, when hunters are thought to have come back with the goods. The remainder of the day involves grazing on foods such as nuts and dried fruit.
It says the key to losing weight and maintaining weight loss long term is having regular meals and cautions that nuts and dried fruits, though high in nutrients, are also high in energy ( calories) that can add up.
David Katz, author of Way to Eat, says eating more foods direct from nature is far better than the diet most people typically eat, but adds: “How the Paleo-type diet compares in terms of long-term outcomes to an Asian, Mediterranean, vegan or other optimised diet, we just don’t know.”
The Caveman diet: Food for thought
A diet that includes whole, unprocessed foods is the basis of most healthy diet recommendations, but so are whole grains, low-fat dairy and legumes.
Including these food groups will help meet nutritional needs and contribute to a well-balanced diet plan. You can satisfy dietary requirements without these foods but that requires careful planning and supplementation.
If the Paleo or Caveman diet appeals to you, consider supplementing the plan with calcium and vitamin D after speaking to your GP or a registered dietitian.
Eliminating all grains, dairy, processed foods and sugar will probably lead to weight loss but it may be tough to follow this plan long term due to the diet’s restrictive nature.
Kathleen Zelman is director of nutrition for WebMD. Her opinions and conclusions are her own.