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Book Reviews: Holistic Health, Integrative Nutrition, Natural Remedies

The Metabolic Typing Diet


William Wolcott and Trish Fahey

2002: Random House, New York, NY

428 pages



            The Metabolic Typing Diet, by William Wolcott, along with The Nutrition Solution, by Harold Kristal, are the two most important metabolic typing sources available today. Much of the information is similar between the two books, while The Metabolic Typing Diet focuses more on different foods for different individual biochemistries; it has about 50% more pages. The theory of metabolic typing is that no two people have exactly the same metabolism, just as no two people have the same fingerprints or DNA (identical twins have DNA changes between them after conception). The application of this theory can be applied to almost any disease that a person is afflicted with, since most chronic disease states involve metabolic imbalances. This more complete theory of metabolic typing has been developed by Wolcott and Kristal from the more divergent findings of previous researchers in the 20th century. These previous biochemical researchers include: Weston Price, D.D.S., George Watson Ph.D., Francis Pottenger, M.D., William Kelley, D.D.S., Roger Williams, Ph.D., and Royal Lee, D.D.S.


            The Metabolic Typing Diet book starts out with a very interesting first sentence in the Foreword section “I first began to investigate metabolic typing almost fifteen years ago, after hearing reports of the exceptional clinical results that people were achieving with it”. Unfortunately, there are no clinical results that have been published on metabolic typing in America. There have been articles published by most of the now deceased authors listed above, but no mainstream contemporary articles on metabolic typing have been published by anyone, whether they “believe” in metabolic typing or not. This is a shame, since metabolic typing has much scientific grounding and deserves to be taken seriously by the bio-medical community. When the author of the Foreword section (Etienne Callebout, M.D.) wrote of the “exceptional clinical results” of metabolic typing, this assumedly was on a case-by-case basis, which is, for better or worse, what occurs in the holistic health field in general. Dr. Callebout resides in Great Britain, which has a somewhat different definition of what is clinical practice.  However, bio-medical articles are accepted for publishing by journals from all over the world, and metabolic typing, wherever it is practiced has still not broken this published article barrier.


            As with The Nutrition Solution book, Wolcott’s Metabolic Typing Book explains the four different metabolic types: sympathetic, parasympathetic, fast oxidizer, and slow oxidizer. The first two metabolic types are influenced primarily from a part of the central nervous system called the autonomic nervous system. The other two metabolic types are more influenced by the oxidative biochemical system, which is much more well-defined in its actions on digestion and assimilation of foods and other nutrients.  Sympathetics and slow oxidizers have relatively lower metabolisms. Heavy foods such as beef and pork tend to slow them down even further, and they often cannot properly digest large amounts of these foods. These two metabolic types tend to do better on carbohydrates, which are burned much faster than the protein and fat in heavier foods.  Sympathetics and slow oxidizers are termed “carb types”. In contrast, parasympathetics and fast oxidizers have relatively higher metabolisms. They can handle a heavy meal much better than other people. However, carbohydrates are too “fast” for them---too many carbohydrates, especially if they are not balanced with protein and fat, will be burned too quickly, resulting in various problems, including blood sugar swings and/or mental disturbances. Parasympathetics and fast oxidizers are termed “protein types” although fat is also found in abundance with most foods high in protein. In Wolcott’s book, there is also a third “mixed” metabolic type, which is neither a carbohydrate or protein type. Wolcott originally followed the teachings of Dr. Kelley, who emphasized the autonomic system, while Kristal built upon the research of Dr. Watson, who emphasized the oxidative system. At first, it appeared that the results of the two different systems were completely contradictory, but later it was found that they complement each other, as will be described below. However, there is still much to be learned about the mechanisms of metabolic typing.


            Interestingly, and up to this point unresolved, is the observation that intake of different foods causes a person’s blood pH to go up or down depending on their metabolic type. Carbohydrates raise blood pH for the autonomic types, and lowers blood pH for the oxidative types. Conversely, protein lowers blood pH for the autonomic types, and raises blood pH for the oxidative types. Blood pH, or the number of H+ ions in blood, falls within a very narrow range of 7.35 to 7.45, with the average being 7.40. Any blood pH change outside the above limits will immediately cause drastic breakdowns in metabolism and/or nerve function, such as seizures (high blood pH), or acidosis leading to coma or death (low blood pH). Any blood pH within the range of 7.35 to 7.45 is considered clinically normal, but that does not mean the person feels well or even is well. Some people are sensitive to very minor blood pH changes, and anything outside of the optimal blood pH of 7.40 may be felt as a number of different symptoms. This is why people with a slightly high blood pH of 7.41 to 7.45 (the parasympathetics and slow oxidizers) should eat protein or carbohydrates, respectively, to lower their blood pH toward the optimal 7.40. People with slightly low blood pH (the sympathetic and fast oxidizers) should eat carbohydrates or protein, respectively, to raise their blood pH toward 7.40.


            Although the above theory does not have a concrete reason for why a certain food raises or lowers blood pH in different people, it does go a long way in clearing up many confusing results that the bio-medical community published in the past. For example, it was long thought that eating too much fat led to heart disease. Along came Dr. Atkins, and all of a sudden eating fat for many people actually lowered their cholesterol and other risk factors for heart disease. Some people do great on the Atkins diet, some do not. Similarly, some people do very well on the carbohydrate-rich Ornish diet, and some do not. Obviously, not everyone has the same genetics, which largely determines their metabolism, otherwise everyone would have done well on either a high-fat/protein diet or the high-carbohydrate diet. Results like these are confusing to clinicians, because they don’t take into account biochemical individuality and differing rates of metabolism. Many clinicians follow a “one size fits all” dogma of diagnosing and treating diet-related illnesses. With all of the conflicting information generated from different diet plans during the last fifty years, it should be clear that there is simply not one type of diet for everyone. This is exemplified by Wolcott stating that eighty percent of Americans cannot find lasting solutions to their chronic illnesses after trying conventional doctors (and dieticians).


Some dietary differences do have a kind of common-sense element to them, however. For example, Eskimos have been eating Caribou meat and Whale blubber for thousands of years, and yet their rates of heart disease are no greater than anyone else. This makes sense, since the Eskimos live in a very cold environment, where humans and animals need to constantly generate body heat, thus their metabolisms are high. They can burn fat quickly, before it becomes a problem. Conversely, tropical cultures have been thriving on complex carbohydrates such as fruits, vegetables, and rice for thousands of years, and their rates of diabetes (a disease associated with excess carbohydrates) are not high. Unlike the Eskimos, there is no need for people who live in the tropics to generate excess body heat to survive, since there is plenty of heat from the blazing sun in their environment. In fact, slowing their metabolism would be a benefit to people in the oppressive heat of the tropics. If the two traditional diets were switched, however, what would happen? Could the Eskimos thrive on carbohydrates? Conversely, could the tropical cultures thrive on a high protein and high fat diet? Probably not, since both of their metabolisms have adapted to the food in their environment that is available to them, and to the external conditions such as temperature. Of course, there have been a great deal of human migrations and genetic blending between distant cultures in the past, which can make typing of metabolisms challenging.


            There are also other factors that influence metabolism, and Wolcott does mention these in the second half of the Metabolic Typing Diet book. The other factors influencing metabolism that Wolcott mentions are: anabolism/catabolism (the building and taking apart of molecules), endrocrine (hormone) type, acid/alkaline balance, prostaglandin (a type of hormone) balance, constitutional type, electrolyte (salt) balance, and blood type. The first three factors listed above are actually essential to metabolic typing itself, while the last four are merely related to metabolic typing and not necessarily integral to it. Wolcott and others believe that disease arises from biochemical imbalances in one or more of the above metabolism-influencing factors. In addition, different nutrients affect the four metabolic types in different ways (as mentioned earlier with the example of carbohydrates vs. protein). By definition, an imbalance means that one side of the system is dominant over the other.


Certain nutrients can restore metabolic balance, depending on the metabolic type in question, while other nutrients may strengthen the dominant imbalance further, thus creating even more imbalance. This is what happens if protein types eat too many carbohydrates or carbohydrate types eat too much protein and fat. Wolcott provides charts for these imbalances, along with different nutrients, including vitamins, minerals, and dozens of different foods. Wolcott provides both a self-test to determine which metabolic type someone is, along with dozens of pages of nutrient recommendations for the protein, carbohydrate, and mixed types. He recommends that protein types have about 40% protein, 30% fat, and 30% carbohydrate in their diet. Any diet with a protein amount above 25% of total calories should first be cleared with a physician, since protein can be hard on the kidneys and pancreas. Carbohydrate types should eat about 25% protein, 15% fat, and 60% carbohydrate. Even this percentage of carbohydrate is relatively low compared to a vegetarian, whether they include fish or eggs in their diet or not. As you may have imagined, Wolcott recommends 50% fat and protein and 50% carbohydrate for mixed metabolic types (30% protein and 20% fat). This is somewhat close to Dr. Sears’ Zone diet of 60% fat and protein, and 40% carbohydrate. If the Zone diet were matched up against Wolcott’s recommendations, it would fall between the protein type and the mixed type in nutrient content.


            Wolcott’s book is very good; it contains more useful details than Kristal’s, although Kristal’s seems to provide a somewhat clearer picture of the overall metabolic typing theory and how it relates to disease. Both books are indispensible to anyone attempting to understand metabolic typing. A practical person without a degree in Biology or Biochemistry may want to choose Wolcott’s book, if they had to buy one of the two. A physician, clinician, or bio-medical researcher may prefer Kristal’s book instead.




General Importance to Field of Nutrition: A

Importance to Bio-Medical Field: C

Importance to General Public: A

Quality of Information/Data/Research in Book: B

Quality of Scientific References in Book: C


Overall Rating: B

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