Metabolic Typing

The Metabolic Typing Diet by William Wolcott examines the work done by Dr William Kelley on establishing comprehensive guidelines for metabolic typing. Wolcott worked as Dr Kelley’s research assistant and then as his “trouble-shooter” helping the metabolic typing clinics with clients who needed extra help.

There are 8 different components of metabolic typing, the most important being how balanced the autonomic nervous system (ANS) is, and the oxidation rate. Dr Kelley discovered the different metabolic types after he cured himself of cancer with a vegetarian diet, but found his wife needed a high protein diet when she developed a chronic illness. He found that many people had imbalances in the ANS, some being parasympathetic dominant (ie. the sympathetic was weak) and some being sympathetic dominant, while some were more balanced.

If a person was sympathetic dominant, a vegetarian or high carb diet strengthened the parasympathetic side, bringing the person into balance. A parasympathetic dominant needed a high protein, low carb diet to come back into balance. A person who was fairly balanced needed a more mixed diet with a wider range of nutrients to stay in balance. This system worked well for most people, but there were some who didn’t thrive on it.

Wolcott then came across the research done by George Watson on oxidation rates. Those Watson called fast oxidisers (who burned carbohydrate very quickly) needed a high protein diet, like parasympathetic dominants. Slow oxidisers needed a diet like the sympathetic dominants. In most cases, parasympathetic dominants are fast oxidisers, and sympathetic dominants are slow oxidisers, so the diets match. A person who is fairly balanced in both areas is termed a Mixed Absolute and needs a mixed diet.

The problem arises when a parasympathetic dominant is a slow oxidiser, or a sympathetic dominant is a fast oxidiser, so that the diets don’t match. In this case, usually the oxidation rate takes precedence over the ANS imbalance, when determining which diet is suitable. Or this metabolic type, known as a Mixed Relative, might need to eat the Mixed diet.

Kelley and Watson had also both discovered that the different metabolic types react differently to vitamin and mineral supplementation. Each developed a list fo which supplements were suitable for each type. Unsurprisingly, they were very similar.

Kelley developed a very comprehensive questionaire (with about 3500 questions) which he used in conjunction with physical tests to determine all the variables of a person’s metabolic type. Each person would then get a personalised program covering their best diet, plus appropriate supplementation and any other recommended therapies. Over time, shorter questionaires have been developed until there are now 4 levels. A brief summary is below, but for more details see and

  1. The Basic Program, which comes from the book and includes a 65 part questionaire to determine your type, and instructions on how to fine tune your diet.

  2. The Intermediate Program, which includes a more detailed questionaire and a consultation with a trained Advisor. This gives you a more detailed breakdown of your typing and supplement recommendations. Go to to check out the questionaire. At the time of writing, this program costs $US105 which doesn’t include the supplements.

  3. The Advanced Program has more questions again, plus some physical tests. This level costs $US270 and the questionaire can be previewed at

  4. The Comprehensive Program which gives you Kelley’s complete analysis and costs $US520

For many people, the basic program will be enough for them to get some guidelines on the best way for them to eat. But for those with serious or chronic illnesses, or those who are Relative Mixed, one of the more advanced programs may be necessary. I can’t comment on the effectiveness of the more advanced programs, but can give you my impressions of the value of the book.

The book firstly covers the theories behind the diet. Then it provides the questionaire for determing your type. The next section covers the three main diets, followed by instructions on how to get started and how to fine tune it your diet to get it right for you.

The diets themselves are very similar to those discussed in Biobalance by Rudolph Wiley. They are also similar to Robert McFerran’s metabolic diets, which are largely based on Watson’s oxidation rate studies & Wiley’s Biobalance work. The Protein type = Hunter-Gather, the Carbo type = Agriculturist and the Mixed = Mixed. The main difference between these diets and McFerran’s are that McFerran doesn’t recommend grains/dairy for either type, while Kelley and Wolcott allow them for all types.

I believe the concepts discussed are among the most advanced in nutrition today. To my knowledge, this is the only metabolic typing system that includes 8 different components. So it is more advanced than other metabolic diets including the blood type diets and I would anticipate that the comprehensive program is excellent. But the book has it’s drawbacks, some of necessity :

  • The questionaire is much shorter than the full program. If you are clearly a Protein type, a Carbo type or a Mixed Absolute, you should be able to tell which type you are. But if you are a Mixed Relative, this may not be so easy. (see “case studies” below)

  • From my personal observations, I believe that grains are not suitable for Protein/Hunter-Gather types, but can be suitable for Carbo/Agriculturists or Mixed types. I wouldn’t recommend wheat for anybody though – better grains to try are amaranth, buckwheat, quinoa, rice, kamut or spelt. Corn or millet may be OK in small doses.

  • Dairy is allowed, as long as there are no allergies. However, many people are sensitive to dairy without realising it, and due to the way it is processed, (pasturised and/or homoginised) most dairy products are not good foods. Raw dairy is tolerated by most people though, or you can make it into kefir or yoghurt.

  • There is not a lot of discussion of what fats are suitable for each type. While saturated fats are tolerated well by Protein types and poorly by Carbo types, there is room for more research on vegetable oils. For example, some people recommend flaxseed oil, while others report that not everybody can metabolise it. Some experts recommend coconut oil, while other report it makes them gain weight. I suspect this is due to metabolic differences.

  • There is no list of what supplements are suitable for each type. This may be because they are reluctant to make recommendations unless a more detailed analysis has been done, but I found this a major drawback.

  • The recommended way of starting each diet is to start with a full portion of an allowed protein, and a very small portion of carbohydrate. You then increase the carbohydrate each meal till you stop feeling sick. This method works fine for Protein types who will feel good quite quickly. But for a Carbo type, this seems to be the wrong way round. I would recommend Carbo types start with a small amount of protein and a moderate amount of carbs and increase or decrease the protein to find their point of balance.

I “trialled” the questionaire on 3 people :

Case Study 1 :

First I tried it out myself. I scored 40 points for the Protein diet, 16 for the Mixed and 7 for the Carbo. Very clearly a Protein type. This ties in with what I have learnt about my nutritional needs over the last few years. So I’m an example of someone whose ANS & oxidation types are compatible, and the questionaire worked well for me. The majority of people would probably find this to be the case.

Case Study 2 :

Client A then tried it out. He found a lot of the questions quite hard to answer. For eg, a question that asked whether he felt better on sugars, meat or equally good on either (Mixed). He feels equally bad on either but had to choose the Mixed answer. The correct response for him would be that he felt best on carbs, but not fruit or refined carbs.

He scored 26 Mixed, 22 Carbo, 12 Protein. This would make him a Mixed type with leanings towards Carbo. But he has found that his best diet is mostly vegetarian, with small amounts of light animal protein. He does burn up calories quite quickly, so he needs reasonable quantities of high density, unrefined carbs like whole grains, beans, nuts and seeds.

I think he is a Mixed Relative, with a sympathetic dominant ANS, but tending towards fast oxidation. In his case, rather than needing the Protein type foods, the ANS category is dominant, which means he doesn’t feel good on the heavy proteins recommended for a fast oxidiser. Rather he needs to favour the higher calorie foods in the Carbo range.

Case Study 3 :

Client B, has been suffering from acid reflux so was keen to learn more about the foods that would be best for him. His score was 29 Protein, 22 Carbo, Mixed 7. This theoretically makes him Protein type. It was clear as we went through the questions together that his appetite and preferences were for the Protein type foods, and he had many of the physical characteristics associated with that type. But he consistently reported that he felt bad on the heavier foods, and better on the lighter foods.

This led us to the conclusion that he was actually a Mixed Relative type, despite having very few Mixed answers. It appears that he has a parasympathetic dominant ANS, but is a slow oxidiser. He is currently trying out different aspects of the Carbo and Mixed diets to see which works best.

People who think they are Mixed Relative after doing the questionaire might find it useful to read another small book about Kelley’s metabolic typing work – Medicine’s Missing Link by Tom & Carole Valentine. This predates Wolcott’s book by some 10 years. It doesn’t give details of the diets but does have lists of characteristics that may help pin down your type.

It can also give extra information to those who are confident of their type. After examing the lists, I now believe I have a fairly balanced ANS, maybe even tending slightly to sympathetic dominant. But I am very definitely a fast oxidiser.

Summary :

If you want to improve your diet, it is vital to know what metabolic type you are. Unless you want to spend the big bucks being fully tested, this is currently the best indicator I know of. But use some judgement when interpreting your test results.

Once you have determined your type, you can follow Wolcott’s guidelines to fine tune your diet. Or you may find other diets in the same “family” work equally well for you. Out of the metabolic diets, I think the most advanced is McFerran’s, though I believe Agriculturists can (and in some cases should) eat certain grains.

See the Dietary Overview page for the groupings.