Wellspring UK, which is set to run for the third summer, will accommodate around 100 youngsters, compared to 30 in 2006. Last year 52 students aged 12 to 18 attended the camp.

The increase in numbers has seen the camp move from the University of Cumbria Campus in Penrith to a new home at the YMCA's National Centre in Newby Bridge.

"Every time there is a news story about childhood obesity, we get a flurry of calls", said Wellspring UK Camp Director Ian Carter, "We are expecting around 100 students to attend camp this year. There is a tangible feeling among the parents we speak to that they want to take action before it is too late."

It is estimated that 24 per cent of Britain's children are obese. Studies have shown that along with poor diet, children aren't exercising enough – 18 per cent do less than an hour of physical activity every week.

Youngsters who attend the camp, which runs from July 6 to August 30, will engage in activities like abseiling, rock climbing and canoeing while pursuing their daily goal of 10,000 steps per day. Daily menus include three meals, two healthy snacks, plus unlimited foods like fat-free yoghurts, fruits, and salads.

Vitally, those who attend Wellspring receive Cognitive-Behavioral Therapy in group and individual sessions that help them change the way they look at diet and activity.

Ian Carter said: "Wellspring UK's techniques are one of the most widely accepted approaches to long-term weight-loss success. Yes, the young people who attend the camp lose a lot of weight during their stay, but the weight loss isn't temporary.

"Wellspring changes behaviours for a newfound healthy lifestyle. We teach campers how to approach diet and exercise in their everyday lives so when they leave us they are equipped to make healthy choices for long-term weight control."