Have you ever wondered why discussions about what to eat can get so intense and be incredibly polarizing? Vegan versus paleo, cooked versus raw, etc. One reason is that food is part of our tradition and our identity, and most people feel very strongly about this. The other reason is that people are different, and indeed need different diets. Last month, I started examining the common principles of indigenous diets. This month, I’m exploring different metabolic types, as researched by Dr. Price and other scientists.

While the work of Dr. Weston A. Price is well known (albeit, often misinterpreted as synonymous with a purely-meat diet), findings from other scientists in the nutritional field are less known.

For instance, Physician Francis Pottenger, Sr. was a pioneer describing the function of the autonomic nervous system, around the same time as Dr. Price’s career. The autonomic nerves directly control all internal organs and its functions; including, heart rate, immune function, endocrine system, and all digestion. It consists of two parts: the sympathetic and parasympathetic nervous system. Each branch contains its own nerves connecting to the same organs and glands; however, each produces opposite effects. Simply put, the sympathetic branch activates the fight-or-flight response, increasing heart rate. This results in more blood pumping to the brain (for quick thinking) and muscles (for quick movement), while the immune system and digestion slows down. When the parasympathetic nerves fire, the opposite happens: heart rate slows down, and the immune system and digestion is turned on. This is the regeneration system of the body which is especially active during sleep and rest. In reality, this is a very complex system with both branches working together in synergy and allowing us to adapt to any situation in life.

Over many years of close observation, Dr. Pottenger found that not all people were born with a balanced autonomic nervous system. Some of his patients were born sympathetic dominant or parasympathetic dominant. He observed that these three different groups (the balanced type, dominant sympathetic, and dominant parasympathetic) reacted to different nutrients – such as calcium, magnesium, and potassium – in different ways. Dr. Pottenger used these three nutrients to bring an imbalanced autonomic nervous system back into balance, which helped his patients’ conditions improve.

Dr. William Kelley, a dentist that cured himself of pancreatic cancer during the 1960s, went even deeper into nutritional healing. He had so much success with his nutritional approach that he became somewhat famous – not by the mainstream media or medical system, but by health-seeking patients that had given up on by the allopathic medical system. Continuing the work of Dr. Pottenger, over many years of clinical observation, based on the autonomic nervous system, he defined ten different metabolic types.

Not only did Dr. Kelley distinguish between balanced, sympathetic dominant, and parasympathetic dominant patients (and their different nutritional needs), he also took into account the efficiency of the autonomic nervous system. While he observed that some people thrived on a nearly all-raw, plant-based diet, he had patients who needed most of their food cooked to heal from their ailments. Some couldn’t tolerate leafy greens or citrus, but regularly needed fatty, red meat; while others thrived on unlimited fruit with barely any meat but lots of plant-based foods.

Dr. Kelley’s belief was that the sympathetic dominants originated from warm regions with a long growing season, for which the land produced a rich supply of grains and vegetables, plus a lot of pasture for dairy products. These people did well on a more vegetarian diet. On the other hand, the parasympathetic dominants came from northern regions with a very short growing season, and these people survived and thrived on a meat-based diet with little plants. The balanced types originated from the regions between, where a wide variety of foods, including grains, roots, meats, and fish, were available.

People from different regions adapted to their local food supply with their different nutritional profile, and, as long as they ate what their ancestors ate, enjoyed optimal health and well-being.

For reference and further reading, check out Nutrition and Physical Degeneration by Weston A. Price, D.D.S. and Nutrition and The Autonomic Nervous System by Nicholas J. Gonzalez, M.D. Check out the conclusion of this four-part series, in which I cover how to determine which diet is best for you.