The basic argument for following this way of eating is that, for most of human history, it is how we ate, and it subsequently shaped our genetics.
This is particularly true in terms of how we, as humans, respond to the foods we eat, to the prevention of disease, and the vitality of our species. While there have been massive changes in the food supply—starting with the agricultural revolution 10,000 years ago, then, the advent of dairy farming 5,000 years ago, and the more recent industrial revolution—our genetic makeup has not kept pace.
Humans do adapt to changes. For example, the genetic mutation that led to the development of adult lactase persistence (ALP) - allowing some of us to digest lactose in milk into adulthood - took place very recently, from an evolutionary standpoint. But when looked at in terms of human generations, we actually adapt very slowly. This can result in an incongruence between our physiology and our environment. That is the case with the typical modern diet in the Western world. Over 70 percent of the foods we eat were introduced since our last major evolutionary change and we simply haven't caught up.
There are many nutritional advantages to following a more ancestral nutrient-rich diet comprised mainly of fresh fruits, fresh vegetables, fish, shellfish, grass produced meats and organ meats, free-range poultry, free-range eggs, nuts, and certain healthful oils.
The Paleo Diet avoids or eliminates processed foods containing refined sugars, refined grains, refined vegetable oils, trans fatty acids, salt, and added chemicals. Fresh fruits and fresh vegetables, good sources of healthier carbohydrates, are consumed ad libitum in lieu of refined sugars, refined grains, and processed foods. As a result, The Paleo Diet is a low glycemic load diet which promotes normalization of blood glucose, insulin, and helps prevent the metabolic syndrome.
In addition, the foods that constitute a modern Paleo Diet contain few problematic dietary anti-nutrients such as lectins, which can lead to a host of health concerns, including autoimmune diseases.
Ultimately, providing our physiology with foods that match our genetically determined nutritional requirements is why The Paleo Diet will provide you with long lasting health.
