OBESITY in children is the equivalent of a ticking time-bomb leading to serious ill-health, such as heart disease and stroke, in adulthood.

In Scotland, that danger is looming for almost one-third of children, who are overweight, including 15% who are obese or severely obese.

This time-bomb must be defused if we are to prevent a reversal of the rise in life expectancy and the NHS being overwhelmed by the demands of an increasingly sick population. It is a problem that has been particularly resistant to traditional health campaigns, but the £1.7m project to provide healthy weight programmes to children and families across the country announced by the Big Lottery Fund Scotland yesterday could be the key to unlocking it. The Healthy Powerful Communities (HPC) programme will build on the success of pilot projects, including one in East Ayrshire. These changed the lives of severely overweight children through the tried-and-tested combination of more exercise and better diet. The crucial difference, however, was that the whole family took part in activities which were enjoyable as well as calorie-burning. At the same time, parents and children were also helped to adopt a healthier eating programme.

This is recognition that children are at the mercy of their family's lifestyle. The extent to which parents determine their children's future health is evident from recent research from the Rowett Institute of Nutrition and Health at Aberdeen University, which showed mothers' diets before and during pregnancy were a factor in childhood obesity and problems such as heart disease in later life.

The effectiveness of the HPC approach can be gauged by the fact that many of the participants (both children and adults) continued their activities after the 10-week programme ended.

The Commonwealth Games is expected to motivate people to increase their fitness and take part in sport but there is a danger that the legacy of new enthusiasm does not reach the areas where it is most needed. The higher incidence of obesity in deprived areas has many causes. Access to facilities is one and the siting of new sports venues in the east end of Glasgow should have a transformative effect on attitudes as well as on the physical environment. But the link between deprivation and obesity is entrenched so a community-based programme offers the best hope of breaking the cycle.

With pre-school children in Scotland now being treated in hospital for obesity, intervention must start at an early age. This has been recognised by the Scottish Government, which plans to give every toddler in Scotland obesity checks. But it must never be too late for children and young people. When healthy eating and exercise habits are formed at a young age, they last a lifetime. This National Lottery funding should begin to turn the tide towards fitness so that Andy Murray's triumph, inspiring a generation, will be followed by a second wave of widespread participation in sport following the Commonwealth Games next year.