America is home to the fattest people in the Western World and being overweight is now the 'norm', according to a new report.
The U.S. has the highest Body Mass Index (BMI) for men and women among high-income countries, with average scores of more than 28.Under World Health Organisation guidelines, a BMI of 18.5 to 24.9 is considered 'healthy', 25 to 29.9 is overweight and 30 or above is clinically obese.
Being overweight or obese raises the risk of heart disease, diabetes, some cancers, arthritis and other health conditions.
The report showed that in 2008 more than one in ten of the world's adult population – around half a billion – were obese, with women more likely to fall into the category than men. The total is nearly double the level recorded in 1980.
For British men, the average BMI was 27.4, matched by Cyprus and Luxembourg in Western Europe. This was up from 24.7 in 1980.
Among the rest of the world, other high-scoring countries included Russia (27.2), Israel (27.3) and Malta (27).
Worldwide, those in Pacific Island nations such as American Samoa were the heaviest overall.
BMIs there average 34-35 kg/m2, up to 70 per cent higher than some countries in Southeast Asia and sub-Saharan Africa.
Japan has the lowest BMI - 22 for women and 24 kg for men - followed by Singapore.
Altogether, findings from three global studies looking at BMI, cholesterol and blood pressure over the past 28 years were published in The Lancet medical journal.
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.'
A growing and ageing population also meant the number of people with uncontrolled high blood pressure rose from 600million in 1980 to nearly a billion in 2008.
Although average levels of blood cholesterol fell in Western countries, they increased in Asia and the Pacific region.
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.'