I first began to investigate Metabolic Typing almost 15 years ago, after hearing reports of exceptional clinical results that people were achieving with it. I was intrigued when I learned of this novel nutritional technology, one that somehow enabled clinicians to identify the highly specific dietary needs of individuals. At the same time, of course, I was skeptical. It sounded a little too good to be true, and was based on concepts that seemed highly unconventional, even within the context of alternative medicine. Nonetheless, I decided to follow up on the subject, in case there might be something of value I might discover.

Back in the 1980s, I was, like many other clinicians, a true believer in the value of diet and nutrition. But like everyone else, I was also continually frustrated by the contradictions and complexity inherent in nutritional science. Nutritional therapy clearly held a great deal of potential as a primary therapeutic approach, yet there were so many practical challenges involved in applying it in clinical settings. Health professionals simply had no reliable means of evaluating peoples' dietary deficiencies and recommending predictably effective nutritional protocols. Time and again I had encountered the same frustrating dilemma: a dietary program that worked very well for one person would produce little or no beneficial results for someone else. There seemed to be no readily available solutions on the horizon.

Then in the mid-1980s I heard about a group of scientists and clinicians in the United States who had, over a period of years, evolved a unique way of addressing this problem, with a system they called metabolic typing. Researchers such as William Kelley, George Watson and Roger Williams had built upon the work of scientists and clinicians of an earlier era; men like Weston Price, Frances Pottenger, and Royal Lee. What they all shared in common was a profound interest in a concept that Williams described as "biochemical individuality," or the idea that no two individuals are alike on a biochemical or physiological level.

As far back as the 1930s, Weston Price embarked on extraordinary anthropological expeditions to remote corners of the globe, and uncovered the link between modern eating habits and the incidence of chronic degenerative illness. He also discovered that there is no such thing as a standard "healthy diet." Due to tremendous variations in climate, indigenous food supplies, environmental conditions, and the principles of evolution, adaptation and heredity, different cultural and ethnic groups, over a period of many centuries, developed distinctly different kinds of dietary requirements.

In later years, Watson, Kelley and others did remarkable work in examining what these variations in genetically-based nutritional needs were all about from a metabolic or biochemical perspective. They knew that a given diet upon which some people might thrive could easily cause other people to be sick. But why? What was the underlying scientific explanation for this phenomenon?

One of the factors they discovered early on was the pivotal role that the involuntary or autonomic nervous system (ANS) plays in determining metabolic individuality and in influencing health and disease. There are two separate branches of the autonomic nervous system. One of these branches, the sympathetic system, controls bodily processes that have to do with energy utilization, and is sometimes referred to as the "fight or flight" branch. The other branch, the parasympathetic system, controls bodily activities that pertain to energy conservation, and is often thought of as the "rest and digest" branch.

In most people, one branch tends to be stronger or more dominant than the other, which creates a certain amount of biochemical or metabolic imbalance. If this imbalance becomes too pronounced, disease processes can develop. Interestingly, specific foods and nutrients have the natural capacity to strengthen whichever side of the autonomic system is weaker. As a result, metabolic typing enables people to establish balance within the ANS. This is important, since the ANS is the master regulator of metabolism.

Another primary determinant of what kind of food a person needs in order to be healthy pertains to the rate at which their cells convert food into energy, or the rate of cellular oxidation. The oxidative rate, which is also largely determined by heredity, needs to be kept in balance if the body is to function properly. Some people are fast oxidizers, which means that their cells rapidly convert food into energy. To sustain metabolic balance, these people need foods that burn slowly, such as heavier proteins and fats. On the other hand, slow oxidizers are able to maintain metabolic balance with lighter food (carbohydrates) that burns faster than protein and fat.

In the late 1970s and early 80s, the nascent science of metabolic typing got a tremendous push forward when Bill Wolcott entered the picture and made a breakthrough discovery pertaining to the interrelationship between the Autonomic Nervous System and the Oxidative System. This discovery, which he termed "the Dominance Factor," enabled him to predict, with far greater levels of accuracy and precision than ever before, exactly what kinds of foods and nutrients a person would need to establish metabolic balance. In the years since then, he has single-handedly expanded and refined the foundational principles of metabolic typing to an extraordinary degree. The practical results have proven to be nothing short of spectacular.

By providing dietary solutions that are effectively tailored to peoples' highly individualized biochemical needs, Bill has shown us the true potential of diet and nutrition, and demonstrated the body's superior capacity to regulate and heal itself, once it's given the right raw materials to work with. His methodology resolves so many of the bewildering contradictions and limitations of modern nutritional science. He really has taken the guesswork out of dietary therapy.

One of the many unique aspects of metabolic typing is that it's not something that clinicians use to "treat" specific diseases or symptoms. Rather, it's a "non-specific" approach that allows us to look beyond symptoms, and to analyze the physiological imbalances and biochemical disturbances that underlie chronic health disorders. That's why people who use metabolic typing have the ability to build health and wellness from the ground up, rather than simply trying to address disparate symptoms in a piecemeal fashion. This foundational approach to diet and nutrition produces a health inducing "domino effect" on all the body's systems, and leads to the elimination of multiple symptoms at the same time.

I have used metabolic typing in my clinical practice for a long time, and I'm convinced that it is an unrivaled method for conducting dietary evaluations and developing dietary recommendations. I have found it to be very successful in resolving and/or alleviating the severity of, all manner of health problems: allergies, digestive disturbances, chronic fatigue, anemia, obesity, hormonal imbalances, mood swings, poor concentration, depression, high blood pressure, diabetes, low blood sugar, arthritis and so on. Yet it's important to realize that metabolic typing does a lot more than eliminate symptoms. Because when you balance body chemistry, you then have the capacity to be vibrantly, glowingly healthy, not merely free of nagging aches and pains and ailments.

Unlike other methods of determining dietary individuality, such as blood typing and body typing, metabolic typing is a dynamic, comprehensive system that encompasses all of the body's known adaptation or homeostatic mechanisms. In other words, it doesn't just measure a single fixed variable such as your blood type or body type. Instead, it takes into account many different types of biochemical or metabolic variables, which are subject to continual change and flux over the course of your lifetime.

That's why metabolic typing is a very accurate dietary discipline, not subject to the laws of chance. This is also why it is a very advanced academic discipline, even though it's also a practical, easy-to-use nutritional technology.

There are so many levels to metabolic typing that I am sure it will go on being a wonderfully advanced clinical technology for health professionals. But what is exciting is that this book now provides health consumers with what they have desperately needed for so long: a simple, rapid and dependable way to identify their metabolic type and eat accordingly, and to adjust their dietary regimes as the need arises.

The term "revolutionary" is so frequently over used in our modern era. But in the case of metabolic typing, it's a very apt description. I think you will agree with me when you read Bill Wolcott's marvelous book.

Etienne Callebout
Harley Street, London