How junk food kills the bugs that help us to stay thin

JUNK food kills vital bacteria that help us stay thin, according to a leading researcher.

Professor Tim Spector believes this partly explains our rising obesity levels.

He also claims that a diet which encourages the growth of a range of bacteria could be as effective for weight loss as cutting back on fat and sugar. This includes celery, garlic, unpasteurised cheese, small portions of dark chocolate and, bizarrely, Belgian beer.

Professor Spector of King’s College London, who specialises in genetic epidemiology, says one reason obesity levels have increased is because the range of bacteria in our guts has reduced.

He estimates that the range in our small intestines has reduced in the past 50 years because we now eat more processed food.

In an unusual experiment, his 23-year-old son Tom agreed to spend ten days on a diet solely consisting of McDonald’s burgers, chicken nuggets, chips and Coke.

Scientists took samples from his gut before and afterwards to estimate the number of different species of bacteria. They found that initially, there were 3,500 species but over the course of the ten days this dropped by 1,300 species. Professor Spector said: ‘Microbes get a bad press, but only a few of the millions of species are harmful and many are crucial to our health.

‘Microbes (bacteria) are not only essential to how we digest food; they control the calories we absorb and provide vital enzymes and vitamins. It is clear that the more diverse your diet, the more diverse your microbes and the better your health at any age.’

Professor Spector also believes that a diet which increases the range of species of bac- teria in the gut is as important as cutting fat and sugar. He said that 15,000 years ago our ancestors regularly ate around 150 different ingredients a week and this encouraged the growth of many different types of bacteria. Nowadays most people eat fewer than 20 different food types, and even less if we mainly eat processed food.

Professor Spector is about to publish a book called The Diet Myth. Dark chocolate may be beneficial as it contains chemicals called polyphenols which bacteria feed off, and thrive.

Meanwhile, Belgian lambic beer, which comes from the south-west of the country, is made using naturally occurring bacteria.

‘A diverse diet means better health’