10 October 2011

Ian Gawler Blog: Would you eat like a dog?

Why is it that so many authorities who are really serious about nutrition, and especially nutrition for healing, recommend a vegetable based diet with little or no meat?

To understand, we need to divert a little and consider dogs, cows and digestive systems.


There are three types of animal digestive systems; carnivore, herbivore and omnivore. A classic carnivore like a dog is designed to eat a high meat diet. A classic herbivore like a cow runs on grass and us human beings; well we are omnivores trying to get the best of both worlds. Knowing about our own digestive system, and how it compares to the others, helps us to understand what we are wisest to eat, and what makes best sense when we are eating for recovery.

The Carnivore

A dog has a very specific anatomical set up to enable it to manage the food it eats. Here is the key point regarding meat. Digestion of virtually any food produces waste products. We eat a food like meat or a particular vegetable, we take what we can use from that food and we eliminate the leftovers, the waste products. With meat, the waste products are somewhat problematic; they are rich in nitrites and other potentially toxic bi-products of their digestion. Vegetables do not produce these problematic waste products.

If the metabolic waste products from meat stay in the bowel for long, they can be directly toxic to the lining of the bowel, or they can be absorbed through the bowel and become toxic to the rest of the body.

Now the dog is essentially a scavenging meat eater with a matching anatomy. It has sharp canine teeth for biting and ripping its potential meal into big pieces. Then it swallows quickly before anyone else can steal its share. Therefore it has modest chewing teeth at the back of its mouth and actually does little chewing unless on a bone or equivalent. Next it has just one, relatively compact stomach that secretes almost pure hydrochloric acid to liquefy the lumps of food it has gulped down.

Then the key point; every dog has a very short bowel, and as a result, what we call a rapid transit time. The transit time measures how long it takes food to go through the system; from front to back, or top to bottom.

Because of the potentially toxic nature of the metabolic waste products that come from the digestion of meat, the dog needs to get rid of them quickly. Hence short bowel, rapid transit time.

The Herbivore

By contrast, a classic herbivore like the cow has a very different digestive challenge. It is eating vegetable matter and with grass, needs to be able to digest cellulose. The cow therefore has a very different anatomy. Firstly, there is a need to start the digestive process by grinding the food very finely.  As a result, the cow has no serious biting teeth, but very serious grinders! Whilst the dog’s back teeth are permanent and static, in the same way that adult human teeth are, the cow’s back teeth constantly grow. Cows do so much chewing that they need to continually replace what has been ground down.

Next the cow has four stomachs! Four. The first is like a huge tank which mixes the finely ground grass with water and saliva and literally ferments it. In the process, cows produce large amounts of methane.

So these days, aware conservationists are joining the push to reduce meat consumption as the volumes of methane produced have a major impact on the atmosphere. Also, to grow an equivalent amount of beef protein compared to vegetable protein requires around 18-20 times more land area. Given the huge problems with the clearing of forests and utilisation of land, this is another major environmental rationale for less meat, more vegetable protein consumption.

Back to the cow; after the four stomachs the cow has a very long digestive tract and a much slower transit time than a dog.

The Omnivore

As humans, we are trying to manage eating just about anything, so our anatomical set up is a compromise. We have teeth that can bite and chew. We have one stomach with high acid content and an intermediate length of bowel. While the dog’s transit time is around 6-8 hours, the cow 2-4 days, the ideal human transit time is 18-24 hours.

For people, there is another relevant issue. Fibre in our diet does two important things that are relevant to this discussion. Firstly, fibre adds bulk and regulates transit times. Low fibre, longer transit time. Secondly, it acts as a sponge or a buffer. If we do eat something, or have some metabolic waste products form in our bowel that are potentially toxic, high levels of fibre act as a sponge to absorb the toxic material and usher it quickly out of our system.

Now you probably understand the average Western diet has been high in meat and low in fibre. This means more toxic waste products, less buffering or absorption from fibre and slower transit times. A great recipe for provoking all bowel diseases and some others in the body generally.

Clearly, humans can manage eating meat, but anatomically, we are better designed for vegetable proteins.


1. Had a great weekend leading a meditation teacher training and retreat for Health Professionals with Zen monks from Thich Nhat Hahn’s tradition at the Gawler Foundation’s Centre in the Yarra Valley. There is the wonderful concept of noble conversation amidst noble company, and this was certainly the case as a delightfully diverse group of practitioners gathered and we explored what is a real priviledge, the opportunity to teach another person meditation.

2. I have been in discussion with the Foundation about contributing to some of their programs next year, and next week will outline these plans.


RELATED BLOGS     Food for Life

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BOOKS    You Can Conquer Cancer  Ian Gawler – contains full dietary recommendations for those who are well, and for those who are recovering from cancer

               The China Study     T C & T M Campbell -  Excellent recent research and protein information.                

CDs   Eating Well, Being Well   Ian Gawler – Details the Wellness Diet –a sound diet for all

         Eating For Recovery   Ian Gawler -  Details the Healing Diet for those interested in using their nutrition therapeutically to assist recovering from cancer.


  1. Interesting article but I think it's not the meat that's the whole issue but rather the diet of the Western man....ie processed food and then meat as well rather than meat and natural fibrous fruit, grains ect

  2. This is excellent - a most succinct summary of the key physiological facts. Medical expenses are bankrupting Western countries due largely to the demands placed on our overburdened health care systems caused by bad diet. The optimal amount of meat in a healthy human diet is precisely zero. This is a good source of information - Physicians Committee for Responsible Medicine http://www.pcrm.org/

  3. Great information again. Thanks Ian

  4. What a wonderful article Ian, I changed to a meat free diet 12mths ago and have never felt better. Now I can fully understand why.