Childhood obesity has doubled in England in the last ten years. The condition affects one in four children aged 11-15 and has been increasing in prevalence since the mid 1980's. Where it used to be the view that overweight children grew out of the condition as they moved into adolescence and beyond, improved tracking techniques and predictive models show more and more of them becoming overweight adults.

Childhood obesity has doubled in England in the last ten years. The condition affects one in four children aged 11-15 and has been increasing in prevalence since the mid 1980's. Where it used to be the view that overweight children grew out of the condition as they moved into adolescence and beyond, improved tracking techniques and predictive models show more and more of them becoming overweight adults.

Both the financial impact of obesity and its effects on health are widely published. Reports place the annual cost to the NHS at£1bn while the economy as a whole in England suffers to the tune of£3.7bn. Obesity increases risk for cardiovascular disease, diabetes and high blood pressure and reduces life expectancy by nine years.

While metabolic syndrome - otherwise called insulin resistance syndrome or syndrome x - waits a universally agreed definition many clinicians use the term to describe a cluster of risk factors for cardiovascular disease. At his Care of Childhood Obesity (COCO) clinic at the Bristol Royal Hospital for Children, Dr Julian Hamilton-Shield sees a worrying number of young people who display many of its symptoms:

'In addition to their obesity around 25 per cent have abnormal blood lipids (fat cells), hypertension and poor pancreas function. These are 13 and 14 year old kids and if you leave them as they are a proportion will go on to develop cardiovascular disease, type 2 diabetes and early onset liver disease.'

The United Bristol Healthcare trust (UBHT) service is the longest established and one of only five childhood obesity treatment centres across the country. Dr Hamilton-Shield expects to see ten new children a month at clinic and will have about 150 under his care at any one time. The entry criteria is strict - a child must be above the 98 percentile for weight in its age group.

'We see our patients over a period of 18 months and during that time 83 per cent of them will improve their BMI-SDS - a measure of blood glucose levels in children,' he says. 'Those that don't get on or lose weight in that period probably aren't ready for change.'

The current service has very much developed from its modest beginnings back in 1999. At that time Dr Hamilton-Shield, consultant senior lecturer in child health, was getting a steadily increasing flow of referrals of what Gps thought might be children with endocrine or hormonal disorders. In almost every case a letter went back to the family doctor saying the child had no disorder and would benefit from eating less and exercising more.

In a bid to provide some level of service that addressed the underlying concerns of family and clinician - and with no road map to follow - Dr Hamilton-Shield started the COCO clinic:

'Nobody knew what to do, we were complete novices. We saw the kids every six months, said the same diet and exercise things and they came back just as heavy or heavier.'

The decision to change the clinic from an essentially medical model came following some preliminary research by MSC health and nutrition students at the local university. Diabetes UK also funded PhD student Matthew Sabin who was looking closely at the interaction between fat and muscle cells to be attached to the clinic. With his clinical input, along with dietetic and exercise training support COCO went from six to three month consultations, a better timeframe for reinforcing positive results.

'This core group looked at lifestyles, food and activity,' says Dr Hamilton-Shield, 'and our approach evolved as our experience grew. Now for the first six months of treatment we focus on a balance of healthy living and diet. If that doesn't work we monitor calorie intake, setting requirements not by height as is usual but by the national average for age and sex. If dietary intervention doesn't work we move on to pharmacotherapy.'

Winning this years BUPA Foundation Clinical Excellence Award is a mark of the model's success as it continues to develop. A research nurse is currently running a randomised trial of a new eating therapy and surgical options are being considered for those few patients unable to lose weight. Equally important however and in line with government thinking the clinic is looking to move much of its work into the primary setting.

'This is one of a number of tests for us to argue the business case for a service development not immediately quantifiable through PBR and national tariff, says Robert Woolley, director of corporate development at UBHT.

'The issue for us now,' he continues, 'is to collaborate with the newly configured PCT in a way that gets the best service for patients while allowing both sides to cover their costs so that nobody is making money at someone else's expense. This is where we can get into unbundling to work out a costed service model that will fly.'

Stuart Shepherd