During the primary school period, from the age of 4 to 11 years, the proportion of children who are very overweight doubles (rising from 10 per cent to 20 per cent). This increasing trend continues to adulthood, but the steepest increase occurs during childhood.

Furthermore, during this period inequalities emerge. At school entry, there is little difference in the likelihood of being overweight between groups. However, by age 11, children from minority ethnic groups and those from more deprived backgrounds, compared to more affluent backgrounds are more likely to be overweight.

Excess weight in children is linked to multiple health, emotional and social problems. Schools could provide a critical setting for prevention. Overviews of previous research suggest that school programmes could reduce the proportion of children who are overweight. However firm recommendations could not be made because of weaknesses in these studies.

To address these inadequacies, researchers in the Institute of Applied Health Research at the University of Birmingham worked with school staff, parents, children and community members to develop a programme of activities aimed at preventing the rise in obesity in children. The programme included activities that were thought to be feasible to deliver and acceptable to a wide range of children. Delivered over 12 months, the programme included a daily additional 30 minutes of physical activity within the school day, termly cooking skills workshops where parents were invited to practise cooking a healthy meal with their child in school and a six-week programme in conjunction with a local football club (Aston Villa). The latter included two visits to the club where children participated in interactive healthy eating and physical activity programmes inspired by sporting heroes, and weekly ‘challenges’ where they pledged to make a healthy lifestyle change. Parents were also provided with information about local family physical activity opportunities.

Around 1,500 children aged five to six years from 54 West Midlands primary schools took part in the research funded by the National Institute of Health Research (NIHR), making this one of the largest such studies in the UK. Measurements including height, weight, wellbeing as well as measures of diet and physical activity were undertaken at the start, and then again 15 and 30 months later. After the first set of measures, schools were randomly assigned to either deliver the programme or to continue as they were without this.

Interviews with parents, teachers and children in the schools that had received the programme suggested they enjoyed it and some reported changes to their behaviour. However, after 15 and 30 months, there was no significant difference in weight status or other measures in children who were in the schools with or without the programme.

This finding that a school-delivered skills-based programme was not able to impact on the likelihood of children becoming overweight is similar to findings from two other recent UK studies. One tested a curricular educational programme in primary schools, whilst the other assessed a drama-based programme – both targeting diet and physical activity. Schools are required to deliver knowledge and skills to support healthy lifestyles, but they are only one of several layers of the environment that affect children’s behaviour. Although subgroups of children may benefit, we have consistent evidence from UK studies that overall, school-delivered diet and physical activity programmes are unlikely to halt the rise in childhood obesity.

The UK government’s childhood obesity plan puts much emphasis on activities that schools can do to tackle the problem. It is important that policymakers break the cycle of focusing on schools to reduce the childhood obesity epidemic. Different approaches are needed that consider broader influences from the family, community, media and the food industry.