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The Diet Myth: Tim Spector

We are constantly being bombarded with new diet and nutrition books however from the many that we have read in recent months ‘The Diet Myth’ by Tim Spector stands out for its interesting insights and quality.

The author Tim Spector is a professor of Genetic Epidemiology at King’s College London he is the lead investigator of the British Gut Project thus has a great take on modern diets.

Anyone with just a passing interest in nutrition will acknowledge there are so many confusing and conflicting messages out there. This book does a great job in explaining why we all respond to food so differently and thus why no one diet is suitable for everybody.

Not all about genetics

The scene is set when the author highlights a Canadian study based on over feeding lean sets of twins with identical food and exercise regimes. After 3 months, there was a 3-fold difference between individuals with some gaining 4kg and others up to 13kg in body weight. Clearly genetics alone cannot explain such a big contrast in weight gain.

After many years of research, it is now known that examining the DNA of the microbes in our guts gives a much better predictor of how fat someone is compared with looking at all 20,000 of their genes. This predictability is improving all the time and so goes a long way to explaining why some people thrive on certain diets where’s others suffer.


Microbes are the most primitive forms of life, they were the first inhabitants on earth. Our bodies contain over 100 trillion microbes. Microbes get a bad press but only a tiny handful are harmful. The reality is that they are crucial to our health. They are essential to how we digest food, control the calories we absorb, provide vital enzymes and vitamins as well as keeping our immune system functioning. We have evolved alongside our microbes for mutual survival. Yet recently our microbes are worsening in health and diversity which is having dire consequences.

Declining microbial health and diversity

In the UK 2/3 of the adult population are overweight and if current trends continue by 2030 ½ the population will be clinically obese. These alarming statics and the modern epidemic of food allergy, auto immune diseases, obesity and diabetes can all be traced back to an unhealthy and undiversified microbiome. The main culprits for the decline in microbial health and diversity are:

  • Anti biotics – Taking regular courses of anti biotics has devastating effects of our gut health.
  • Sterile life – our obsession with hygiene is becoming a hindrance as it is effecting the good bacteria as much as the bad.
  • Limited fruit, veg and fibre – the majority of people are eating far too little of these foods.
  • Processed food – Low in nutrients but high in trans fats and sugars which feed bad bacteria.
  • Alcohol – Contributes to killing off healthy bacteria.
  • Stress – Too much chronic stress upsets stomach acid levels and ultimately gut health.
  • Sleep – If sleep is compromised so too is gut health.
  • Gluten and dairy – For many these are inflammatory for the gut.

Thousands of years ago our ancestors consumed around 150 natural ingredients in a week, many people nowadays consume fewer than 20. Of the foods we do eat many are artificially refined and contain just 4 ingredients – corn, soy, wheat or meat.

Steps to take to improve your Microbiome health and diversity

It is obvious we need to take steps to improve our microbiome health, a good start is to treat your gut microbe like a garden – thus provide a fertile environment, prebiotics, fibre and nutrients.

  1. Don’t poison the garden with sugar, preservatives, antiseptic, antibiotics and junk food.
  2. Prebiotics are non-digestible fibres and act as fertiliser in the colon for bacteria. Fresh tomatoes, garlic and onions are all great forms of pre biotic foods. It is also a good idea to have some fermented foods from time to time for example sauerkraut.
  3. Eat a diverse diet rich in fruit and vegetables. Eating with the seasons is a good way to get in lots of diversity, here at CoActive we are big fans of Riverford as they have a great selection of seasonal meat, fruit and veg. (
  4. In moderation strong coffee, dark chocolate, red wine, nuts, natural yogurt and cheese are good for you and your gut health.
  5. Depending on your current health status some intermittent fasting, fasting or cleansing periodically is good for you. This can act as a spring clean for your microbes and thus help kill off unwanted bacteria. We will have more info on this topic in upcoming articles.
  6. Finally, it’s a good idea to test your own microbes. Only by knowing the current health status of our microbiome can we take appropriate bespoke action. The best way to do this is with the British gut project. This is the partner study to the American Gut project which aims to map the human gut microbiome. You can find out more here:

Additional Support

If you have have any questions or would like to book in for a complimentary discovery call to learn more about how we can help, get in touch using the form below.

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