The rapidly rising incidence of overweight/obesity amongst both adults and children in many westernized countries suggests that control of the obesity epidemic will depend on effective programmes to prevent overweight developing rather than on more effective management, important though this latter aspect is. Yet, just as there is no consensus view on the specific details for management of overweight/obesity in childhood, so there is no consensus view on effective prevention. A review of studies, many of which were from North America, on the prevention of overweight/obesity in children found some studies which fulfilled the Cochrane criteria for objective analysis and, of those included in the review, none came out with impressively effective plans for prevention (Summerbell et al. 2005). However some interventions were at early stages in their implementation. Many showed some evidence of changes in behaviours (Summerbell et al. 2005). Thus there is plenty of opportunity for properly conducted, randomized control studies designed to reduce the prevalence of overweight/obesity in present-day child populations.

Some overweight prevention studies have focused on only one contributor to overweight, for example diet. Sustainable weight control and overweight prevention needs broad changes in lifestyles for most families. Measures to prevent overweight should impact on behaviours around diet and activity but also include the family environment. Intervening to modify only diet or only activity is largely ineffective (Anderson 2002).

Constructing effective preventive programmes is complicated by the wide range of stakeholders who are, or could be, involved in programmes for weight control in childhood.