A study by the UN health body finds that deregulated food markets result in more people eating fast food and an increase in the obesity epidemic. Governments could slow and even reverse the epidemic by tighter control of the fast food market.

The new report, published in the Bulletin of the World Health Organization (WHO), found that if governments took decisive action they would be able to prevent people becoming overweight and the long term health consequences that go with it, which include diabetes, heart disease and cancer, Reuters reports.

“Unless governments take steps to regulate their economies, the invisible hand of the market will continue to promote obesity worldwide with disastrous consequences for future public health and economic productivity,” said Roberto De Vogli of the University of California, who led the study.

The research analyzed the effect of deregulation of the economy on the agricultural and food sectors and the impact on fast food.

The study then compared the number of times an individual bought fast food with their body mass index (BMI) in 25 high income countries, between 1999 and 2008.

As the annual number of fast food transactions (or purchases) increased from 26.61 to 32.76 per person, the average BMI also increased from 25.8 to 26.4. Someone with a BMI of 25 or more is overweight, while a BMI of 30 or more is considered obese.

The sharpest gains were in Canada, Australia, Ireland and New Zealand, but the lowest were in countries which have stricter regulation on the fast food market, such as Italy, the Netherlands Greece and Belgium.

But, said Vogli, the data is equally relevant to developing countries.

“Virtually all nations have undergone a process of market deregulation and globalization – especially in the last three decades,” he said.

The director of the WHO’s Department of Nutrition for Health and Development Francesco Branca, stressed the importance of government policy in tackling the problem.

“Policies targeting food and nutrition are needed across several sectors including agriculture, industry, health, social welfare and education,” he said.

Professor Philip James, who has devoted the last four decades to studying obesity, and is an advisor to WHO believes that the only way to tackle the problem is through an all-of-government approach.

“There is no hope unless governments accept that they have to intervene and set new criteria. Publicly funded social and traditional media campaigns are useless when faced with one of the biggest, most powerfully industries globally,” he told Fiona Fleck on the bulletin of the WHO.

He said that an initial step should be to ban all sales of unhealthy foods and soft drinks that can lead to obesity on all public premises such as hospitals and schools.

He added that research shows that humans are only able to make decisions that control primeval emotional responses by their early twenties, and so adolescents are particularly vulnerable to foods which trigger our primitive taste systems.

James cites the example of France, which launched a campaign in 2001 to make sure all school children have access to healthy food, and in 2005 banned vending machines on school premises and increased the price of soft drinks by 7 cents a liter.

He also points to Denmark, where scientists have proven that a 15-month long tax on saturated fats led to a reduction in saturated fat intake.