The modern dietary regimen known as 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 nutritional plan based on the presumed ancient diet of wild plants and animals that various hominid species habitually consumed during the Paleolithic eraâa period of about 2.5 million years duration that ended around 10,000 years ago with the development of agriculture. 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, vegetables, fruit, roots, and nuts, and excludes grains, legumes, dairy products, 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 two small prospective studies of the Paleolithic diet in humans have shown some positive health outcomes. Supporters point to several potentially therapeutic nutritional characteristics of allegedly preagricultural diets.
This dietary approach is a controversial topic amongst dietitians and anthropologists, and an article on the National Health Service of the United Kingdom Choices website suggests that it may be a fad diet. Critics have argued that if hunter-gatherer societies failed to suffer from "diseases of civilization", this was due to a lack of calories in their diet, or a variety of other factors, rather than because of some special diet composition. Some researchers have taken issue with the accuracy of the diet's underlying evolutionary logic.
Also disputed are some dietary recommendations and restrictions on the grounds that they provide no health benefits or pose health risks and are not likely to accurately reflect the features of ancient Paleolithic diets.