It's a big fat figure - and it is getting bigger each year. Britain's worsening obesity crisis is already costing the country £3.3bn annually, a bill that will expand along with our ever-increasing waistlines.
The entire developed world may be putting on weight. But Britain is piling on the pounds faster than most - a trend confirmed by the fact that our children are among the most obese in the world.
While the economic costs of Britain's obesity crisis are alarming, its social consequence could be catastrophic.
A government study commissioned by Caroline Flint, the public health minister, predicts how a fat, depressed underclass is set to sprawl beneath a slim elite. And Britain's children are at the forefront of this social revolution.
"Trends indicate there may be continued polarisation of the population, into the junk food-eating, less-educated poor and functional food-eating, better-informed higher classes," warned a report by the Foresight Programme in the Office of Science and Technology.
The future of the NHS itself is at stake. Once health insurance firms vary premiums by weight, how long will a divided nation support a health service swamped by the poor and obese? It is little wonder ministers are prepared to risk accusations of "nannying" in their efforts to get individuals to change their behaviour.
This week, GPs will be asked by the Government to hand out questionaires to all patients visiting their surgery. The surveys are designed to establish just how unfit and overweight the nation is.
Most people in the UK fail to meet the Chief Medical Officer's recommended guidelines of half an hour of moderate activity at least five days a week. Children should spend an hour exercising every week if they are to fend off the threats of obesity, heart disease and diabetes, but an increasing number are settling in front of the television with a packet of crisps instead.
Physical inactivity costs the nation £8.2bn a year, for example, in lost work days and NHS bills. This week Sport England will publish a survey indicating just how inactive we are. The survey of 364,000 people will show which areas of the country are the most sporty and which age groups are most likely to participate in sport.
Efforts are already under way to save the next generation. One of the most successful pilot programmes to cut weight was run by Hastings and Rother Primary Care Trust, which used a £200,000 health service grant to set up programmes aimed at teenage girls, "overweight and sedentary children" and teenage mothers.
The Girls Getting Active programme, aimed at 10- to 16-year-olds, built physical activity into fashionable and social programmes, including street dance classes. "We wanted to appeal to girls who might not be very sporty, for example with trampolining and power walking and games," said Hayley Martin, Local Exercise Action Pilot (Leap) physical activity co-ordinator at the Trust.
For older people, the thought of signing up for football or hockey after work is deeply unappealing. Some may have been turned off sport at school, and it is this group that often shies away from sporting activities in later life, leading to a host of problems including diabetes, depression, hypertension and heart disease.
Health experts have been trying for years to send out the message that remaining healthy need not involve competitive sport but can be achieved through a host of everyday activities, including walking. To reinforce this message, the National Institute of Clinical Excellence will this month publish a report on how people can integrate moderate exercise into their daily lives.
The health watchdog is expected to recommend that, instead of taking the lift, people climb the stairs or carry the shopping home instead of leaping into the car for a five-minute trip.
There is some room for optimism. A government pilot scheme to get people involved in physical activity has proved an overwhelming success. The Department of Health has invested £2.5m in programmes to get "priority groups" - including overweight children and the inactive elderly - to increase the amount of activity they undertake.
Using novel means to make physical activity fun, the pilots across the country have invested in boxing and tango dance for the over-50s, street dance programmes for teenage girls and "twister on the beach" parties.
The results from Leap have shown a dramatic improvement in the amount of exercise people took. A report to be published this week will show that 60 per cent of participants who were classified as either sedentary or lightly active achieved the Chief Medical Officer's recommended guideline of being moderately active after participating in Leap.
What really convinced the Government that the programme, run by NHS trusts, should be extended across the country is that it showed "physical activity interventions are cost-effective and can save the NHS money in the long term by reducing ill-health".
The programme was designed to improve not only physical but also mental health. Now the Government is to urge local trusts to invest in such programmes. Admirable as these initiatives are, the odds are against them turning the situation around completely. There is - as yet - no example anywhere in the world of an effective national programme that has reduced obesity rates.
According to the Foresight Programme: "There are no proven, national-level precedents for action to reverse obesity. We found insufficient evidence of effective programmes that have reduced obesity ... Indeed, we were told that these do not exist."
Dr Stephen Morris, of the Health Economics Research Group at Brunel University, and an expert on obesity, agrees that there is very little evidence that such policies work. "Initiatives like dance classes on the NHS are probably cost-effective if people actually take any notice. Policy-makers like to suggest advice because advice is cheap. But how many of us have paid the £400 joining fee for a gym and gone three times? The problem is there is very little research as to what interventions actually work."
Looming in the background is the issue of compulsion. If people won't take advice and cannot be tempted from their sofas by dance or football classes, should we start forcing them to be active? The notion is not as outlandish as one might think: ministers are seriously considering forcing parents to accept that their children should be weighed in what will amount to a compulsory obesity screening programme.
This summer the Department of Health announced plans to weigh all children in England when they start primary school, and again when they leave, as part of the Government's campaign against obesity. The results of the survey have not yet been released, but at a Department of Health seminar last week, officials admitted that fewer than half of the children had been measured.
Additional reporting by Martin Hodgson
FIT TO WORK: All together now: exercise for everyone
Amid the gloom of post-war Britain, and during the formation of the National Health Service, the then Labour government launched the first workplace exercise schemes as an incentive for people to start getting healthy.
The schemes, which started at a time when National Service was mandatory, saw thousands of people up and down the country running on the spot, performing star-jumps, sit-ups and stretches.
Before and after work, in factories and offices from Sunderland to Southend, people would take to any large open space and begin to exercise. This was not so much a lifestyle choice as a necessity.
Workers had little say in the matter and did not have the luxury of choosing one of today's hi-tech gyms. Classes were basic and modelled on army-training exercises which could be done out in the open or in any space indoors.
Nor was the drive for fitness confined to working adults. This period also saw the beginnings of physical education for children of all ages.
During the post-war era, Britain was gripped by a fear of recession, and the government of the time had social welfare as one of its priorities. The logic was simple: a fit and healthy workforce would help bring about a fit and healthy economy. This was in the wider context of the time - the drive towards an efficient industry in the interests of the country and its future prosperity.
This was the foundation of what can still be seen today in the corporate football team and office gym membership.
FAMILY HEALTH: 'My daughter isn't being bullied now'
Jackie Inchley's children, Georgina, 12, and Ashley, 9, joined an activity club in Sheffield after concerns about weight and fitness.
The scheme, at the local youth centre, was designed to help overweight children lose pounds and increase their fitness while having fun. The club on Saturday, and after school on Tuesday and Wednesday, offered swimming, dodge ball and dancing. The children were weighed frequently, and within weeks showed signs of improvement.
"I sent my daughter because she was putting a lot of weight on. She did lose weight during the programme and seems fitter," said Ms Inchley, 46.
"Georgina is big, and I have been concerned for a long time about it. Each time she had an asthma attack [doctors] asked how much she weighed. I wouldn't say she eats more junk food than other children, but if it is there she would eat it. I have tried to stop her and gave her fruit, but then it is back to junk food. The school nurse gave me the number of the programme when we were talking about her weight.
"When she first went she wouldn't do anything, but now she goes and she loves it. She can also talk about her problems with other children and not be bullied."