As a dentist Weston Price chose to study races around the world in the 1930's for their outstanding levels of health and exceptionally low level of tooth decay. He picked races that were isolated from modern society. He discovered 14 races including Australian Aboriginies, the Masai in Africa, certain Native American Indians, Islanders off Scotland, and isolated Swiss. They all ate diets of locally obtainable foods, plentiful in protein and animal fats, whether from meat, fish, dairy products or eggs. These races were long lived, productive into old age, and without any appreciable tooth decay (generally 1 tooth in 100 or less showing any decay at whatever age a person was) or degenerative diseases such as arthritis, tuberculosis, cancer, diabetes, heart disease etc.. Other communities living close to the healthy ones with a very similar lifestyle to them, but not including their diet, had more "normal" levels of tooth decay and diseases as we know them today. Each race or community Price studied however, had some striking similarities with the composition of their diets.
They knew how to access and utilise correctly the minerals in their food which was rich in protein and fat. They placed emphasis upon digestion of the foods they ate. Many more minerals are taken from food by eating plentiful fat soluble vitamins - vitamin D (as a complex of 8-12 components and not just the one we get from the action of sunlight on our skin) and vitamin A*, vitamin K2 (which was unknown in Price's time and he called it Activator X) as well as possibly still unknown factors. People in modern society avoid those same fats which contain these factors because they believe they increase cholesterol and make you fat (no they don't!). So they choose the "Healthy Option" low fat varieties at supermarkets and wonder why they are sick.
These healthy races only ate unrefined foods, and with certain foods such as grains, only prepared in a way that deactivates their copious anti-nutrients, such as using a natural fermentation method. They ate next to no foods containing sugar, even sweet fruits. Price certainly showed that a mixture of certain correctly prepared cooked foods with other foods taken raw maintained exceptional health in these races.
We are several generations down the line from the exceptionally healthy. If you read Price's book Nutrition and Physical Degenertion it is obvious that even our physical structure is quite different - the narrow, pinched faces, crowded teeth, hunched backs and narrow hips of mineral depleted people are now seen as normal!
For much more information on Weston Price's work and others following this line of thinking today look at www.westonaprice.org
* Natural vitamin A is not the same as the synthetic version which has received a very bad press in recent years. It seems that synthetic vitamin A increases the need for natural vitamin A and can produce true vitamin A deficiency. Studies showing, for example, that vitamin A is toxic in pregnancy have been performed using the synthetic version. Price found that the races he studied ensured that pregnant women ate MORE food that were rich in vitamin A, going way beyond the level which orthodox medicine now views as safe.