The Paleolithic Diet, AKA the original human diet, is the diet that humans consumed during the Paleolithic era (2.6 million years ago – 10.000 years ago). Our Paleolithic ancestors consumed wild plants and animals that were present in their environment. Meat, seafood, eggs, insects, nuts, seeds, vegetables, and fruit were important components of their diet.
There wasn’t just one Paleolithic diet. The composition of hunter-gatherer diets (both contemporary and ancient) varies seasonally and geographically. Whereas some foragers consume a lot of animal source foods, other rely heavily on plant foods for nourishment. With that said, all hunter-gatherer diets have certain characteristics in common. Among other things, they are largely devoid of grains and contain no dairy foods, refined sugars, or highly processed foods. When compared to modern, grain-based diets, hunter-gatherer diets are low in carbohydrate, salt, and omega-6 and high in protein, fiber, and omega-3.
The foods that line the shelves of modern supermarkets differ from those our Paleolithic ancestors ate. This is not only true if we compare foods that were a part of the Paleolithic diet with modern foods that weren’t available to our preagricultural ancestors, but it also to some extent extends to comparisons between similar types of foodstuffs. For example, modern, domesticated fruit tends to be sweeter and larger than wild, uncultivated fruit.
With that said, the differences that exist between similar types of foodstuffs (e.g., domesticated, modern fruit vs. ancient, wild fruit) are small when compared to the differences that exist between dissimilar types of foodstuffs (e.g., chocolate vs. wild game meat). This is particularly true if the modern Paleo foods are produced from animals and plants that have lived under conditions that match well with their biology.
The Paleo diet concept is built on the premise that we humans are inadequately adapted to eating foods that were recently (from an evolutionary point of view) introduced into our diets, such as grains, milk, and highly processed foods. This idea – that “modern” foods don’t agree with our bodies – is supported by a solid body of scientific research.