Obesity will cost £45 billion a year by 2050 if the epidemic is not brought under control through dramatic changes across British society, a landmark government inquiry into the problem will warn this week.
Soaring rates of diabetes, strokes and heart disease caused by more Britons becoming fatter will cost the NHS alone £6.5bn. But other consequences, such as obese people being unable to work, will add a further £38.5bn to the bill, according to the Foresight report by a team of eminent scientists. The £45bn figure is a colossal increase on the assessment of £7bn annually, produced by the House of Commons health select committee in 2004.
The document warns that, based on the huge rise in the numbers of those dangerously overweight in the past 20 years, 60 per cent of men and 50 per cent of women, and half of primary school-age boys and one in five girls aged up to 11 could be obese by 2050.
Separate research shows that British schoolchildren are 8cm to 10cm, or nearly 4in, fatter than a generation ago. Dr David McCarthy, a Reader in Human Nutrition at London Metropolitan University, has found that a typical 12-year-old girl's weight rose by 7.4kg (more than a stone) from 41.6kg to 49kg between 1987 and 2007, while her waistline grew by 9.5cm (3.7in) from 61.5cm to 71cm in the same period. Boys fared better. An average 12-year-old boy went from weighing 40.4kg in 1977 to 47kg in 2007 - an increase of 6.6kg or just over a stone, albeit over a longer period than girls - and saw his waist grow by 8cm (3.1in) over that period.
The Foresight report claims that obese Britons are not individually to blame for their situation and are, in effect, victims of a new concept which they have called 'passive obesity'. This holds that, given modern lifestyles - such as computers, people driving to out-of-town shopping centres, and children being far less physically active - most people would put on weight in such circumstances.
'The whole environment is conspiring against people. We are putting on weight even when we don't want to, because the forces ranged against us being slim are so powerful', said one scientist involved in producing the report.
Alan Johnson, the Health Secretary, last night compared the challenge posed by obesity to that of climate change and promised radical new measures by the government to try to reverse the tide.
'We know we must act. We cannot afford not to act', he said. 'For the first time we are clear about the magnitude of the problem: we are facing a potential crisis on the scale of climate change and it is in everybody's interest to turn things round.'
But Johnson stressed that obesity posed such a grave threat that it could not be solved by government action alone, that everyone had to play their part and that many different solutions were needed.
But public health experts attending this week's annual conference of the National Obesity Forum are set to criticise what they say is the government's appalling record so far in combating obesity.
Forum spokesman Tam Fry said: 'The current projection that there will be one million obese children by 2010 is an utter disgrace. The major flaw in dealing with obesity so far is the government has concentrated more on cure than prevention. They must begin looking at halting obesity among pre-school children as a priority.'
