One in 10 obese around the world

More than one in 10 people around the world are obese – double the number in 1980, research has shown.

Scientists investigating risk factors for heart disease found evidence of an obesity pandemic as more countries embrace “Western” lifestyles and diets.

In 2008, more than half a billion adults worldwide – 205 million men and 297 million women – were clinically obese.

This means they had a body mass index (BMI), measured by dividing a person’s weight in kilogrammes by their height in metres squared, of 30 or above.

An estimated 9.8% of men and 13.8% of women were obese worldwide in 2008, compared with 4.8% of men and 7.9% of women in 1980.

Pacific island nations had the world’s highest obesity rate, with average BMI levels reaching 34-35 – up to 70% higher than some countries in south-east Asia and sub-Saharan Africa.

Among high income countries, the US had the highest average BMI level of 28 for both men and women. Being overweight is now the norm for the average American.

The picture was similar in Britain, which had the sixth highest BMI in Europe for women and the ninth highest for men. Both men and women in the UK had an average BMI of around 27. The “overweight” BMI range is from 25 to 30.

Three papers published today in The Lancet medical journal analysed global levels of obesity, cholesterol and blood pressure by drawing together available data.

In contrast to obesity, the proportion of the world’s population with high blood pressure fell between 1980 and 2008. This was despite the total number increasing from 600 million to almost a billion.

High income countries achieved the biggest blood pressure reductions, and also saw falls in average levels of total blood cholesterol.

But this good news masked shifting patterns with some countries facing problems not encountered before.

Systolic or “heartbeat” blood pressure levels were highest in Baltic and East and West African countries, matching those in some parts of western Europe in the 1980s.

Cholesterol levels had shown increases in Japan, China and Singapore where they were historically low. Experts believe this partly due to a dietary switch to more animal products and fats.

Britain’s average blood cholesterol level in 2008 was the ninth highest in the world at slightly below 5.5 millimols per litre (mmol/l). However the UK also saw one of the fastest drops in cholesterol level of all high-income countries. Between 1980 and 2008 the average fell from 6.2 mmol/l to 5.4 mmol/l.

Professor Majid Ezzati, from the School of Public Health at Imperial College London, said: “Our results show that overweight and obesity, high blood pressure and high cholesterol are no longer Western problems or problems of wealthy nations. Their presence has shifted towards low and middle income countries, making them global problems.”

Co-author Gretchen Stevens, from the World Health Organisation in Switzerland, said: “We know that changes in diet and in physical activity have contributed to the worldwide rise in obesity, but it remains unclear which policies would effectively reduce obesity.

“We need to identify, implement and rigorously evaluate policy interventions aimed at reversing the trends, or limiting their harmful effects.”

Dr Mike Knapton, associate medical director at the British Heart Foundation, said: “There has been a striking escalation of obesity over the last 30 years and, make no mistake, we’re facing a global challenge tackling the swell in BMI, cholesterol and blood pressure – all leading heart disease risk factors.

“It’s an ugly, upward trend but it can be reversed with effective policies and sensible lifestyle changes, supported by important developments in medicines.

“Global inequalities still exist but it’s not all bad news. We’ve seen marked progress in reducing blood pressure and cholesterol across the developed world, proving lifestyle and medical interventions can work.”