Leading scientists accused the Bush administration last night of putting the interests of powerful American sugar barons ahead of the global fight against obesity.

Professor Kaare Norum, leader of the World Health Organizations fight to prevent millions developing diet-related diseases, has sparked an international war of words with a highly critical letter to US Health Secretary Tommy Thompson. In it he tells of his grave concern over American opposition to the WHO's blueprint to combat obesity. He accuses the US of making the health of millions of young Americans 'a hostage to fortune' because it has failed to take action over the fat epidemic as a result of its business interests, particularly the sugar lobby.

The Bush administration, which receives millions in funding from the sugar industry, argues there is little robust evidence to show that drinking sugary drinks or eating too much sugar is a direct cause of obesity.

Since 1990, successive US governments have blocked WHO calls for action, claims Norum, professor of medicine at Oslo University.

'Obesity rates have risen so that now one in three Americans bears the burden of the very high health risks associated with this condition, with the poorest and most vulnerable worst affected,' he says. 'Obesity rates among American children have risen by 50 per cent.'

Norum is the most senior scientist involved in an attempt to formulate a worldwide policy to fight heart disease and diabetes resulting from a junk food diet. An estimated 60 per cent of disease worldwide is now due to cardiovascular illness, which causes 47 per cent of deaths.

The letter from Norum will put Bush under intense pressure at home to show that he is serious about tackling the epidemic. More than half of all Americans are overweight, and in some states, including Bush's Texas, nearly one-third of the population is classified obese.

The President insists fighting fat is a matter for the individual, not the state. But today The Observer reveals how he and fellow senators have received hundreds of thousands of dollars in funding from 'Big Sugar'. One of his main fundraisers is sugar baron Jose 'Pepe' Fanjul, head of Florida Crystals, who has raised at least $100,000 for November's presidential re-election campaign.

Norum's letter is an angry response to the Americans' decision to submit a 30-page report, criticizing the WHO strategy for its lack of sound scientific evidence. It will be discussed at a key meeting of its executive board in Geneva on Tuesday.

The Bush administration, which receives millions in funding from the sugar industry, argues there is little robust evidence to show that drinking sugary drinks or eating too much sugar is a direct cause of obesity. It particularly opposes a recommendation that just 10 per cent of people's energy intake should come from added sugar. The US has a 25 per cent guideline.

Thompson's representative at Tuesday's meeting will be Bill Steiger, godson of George Bush Sr. He will argue there is no evidence that selling junk food to children increases overweight.

Another leading obesity expert supported Norum, describing America's position as a scandal. Professor Philip James, head of the International Obesity Task Force, a thinktank for experts worldwide said: 'People are far more tuned into what is now a much bigger obesity crisis and are more aware of some of the dangers such as diabetes. When they begin to see children developing these severe health problems, it brings home to people that this is not some vague risk in the future - it is happening here and now.'

Thompson is also due to speak at the World Economic Forum in Davos next week, where he is expected to have a private meeting with Douglas Daft, president of The Coca-Cola Company, one of the major users of American cane sugar and sweeteners.

In an Observer interview today, Britain's Culture Secretary Tessa Jowell urges people who take little or no exercise to start hobbies like DIY and gardening to get active, saying that she wants people to take responsibility for their fitness.

In the UK, nearly 16 per cent of teenagers were found to be obese in 2000 - three times the number reported in 1990.

© Guardian Newspapers Limited 2004

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