Many blamed the food available for rising levels of obesity

A poll of 9,000 people in 13 nations, alongside a BBC investigation into global obesity, found vast variations in attitudes towards food and weight.

Many French get on the scales every day the poll found, while Singaporeans are the least likely to weigh themselves.

People are now said to be getting fatter in most of the world, with the exception of parts of Asia.

The three-day BBC series will look at the problems arising from the trend and what can be done about it.

This study, by market research firm Synovate, questioned 9,000 people in 13 countries across five continents.

OBESITY: WHAT PEOPLE BLAME Food - 40% Lack of exercise - 18% Individual - 13% Genetics - 11%

Few people blamed their government for rising levels of obesity: the largest number of respondents blamed the food that was now available.

People in the UK and the US were the most likely to nominate "no self discipline" as the leading factor in obesity.

These two nations also had the most respondents who said they would be unable to give up fast food.

Some 45% in the UK agreed with the statement "I like the taste of fast food too much to give it up", while 44% of Americans said they would be unable to give up their burgers, pizzas and chicken wings.

Middle east diets

The survey also threw up some other interesting geographical variations.

The results show there's a world of people who cannot deny themselves that hamburger or extra piece of pizza, but probably make themselves feel better by washing it down with a diet cola Steve Garton Synovate Send us your comments

Saudi Arabians and those from the United Arab Emirates were among the top consumers of low-fat food products, meal replacements and food supplements.

They were also the most interested in weight-loss courses, gym memberships and home exercise equipment.

"People are inherently contradictory and nowhere is it more obvious than on such a sensitive and important issue such as their weight," said Steve Garton of Synovate.

"The results show there's a world of people who cannot deny themselves that hamburger or extra piece of pizza, but probably make themselves feel better by washing it down with a diet cola."

A recent study of men and women in 63 countries found between half and two-thirds of men were overweight or obese in 2006.

168,000 people were evaluated by a doctor on a single day. The US was not included in the report. A BMI over 25 is deemed overweight and greater than 30 is obese.

The populations of Canada and South Africa currently lead the way, with an average Body Mass Index (BMI) of 29 - a calculation that takes into account both height and weight.

There is still some debate about the exact health risk posed by rising levels of obesity, but those who are overweight do have a higher risk of heart disease, Type II diabetes and other diseases including some cancers.

It is thought that an increasingly sedentary lifestyle is a major factor in rising obesity rates.

Health analysts warn that obesity-related illness threatens to overwhelm healthcare systems around the world.

Neville Rigby, of the International Obesity Task Force, said: "It is serious for individuals, but it is also serious for countries.

"Reports from the World Health Organization have shown that preventing chronic disease can have major economic benefits, and failing to do so can have major economic disadvantages."

Douglas Smallwood, chief executive at leading health charity Diabetes UK, said: "This survey is a sad indictment of current eating habits in the UK."

Peter Hollins, chief executive of the British Heart Foundation said: "If we are to tackle the growing obesity crisis it is vital that Britain's junk food addiction is addressed.

"But this isn't going to happen whilst a junk-dominated diet is being normalised through the constant barrage of advertising and promotions."

168,000 people were evaluated by a doctor on a single day. The US was not included in the report. A BMI over 25 is deemed overweight and greater than 30 is obese.