We found strong evidence to support beneficial effects of child obesity prevention programmes on BMI, particularly for programmes targeted to children aged six to 12 years. However, given the unexplained heterogeneity and the likelihood of small study bias, these findings must be interpreted cautiously. A broad range of programme components were used in these studies and whilst it is not possible to distinguish which of these components contributed most to the beneficial effects observed, our synthesis indicates the following to be promising policies and strategies:
·         school curriculum that includes healthy eating, physical activity and body image
·         increased sessions for physical activity and the development of fundamental movement skills throughout the school week
·         improvements in nutritional quality of the food supply in schools
·         environments and cultural practices that support children eating healthier foods and being active throughout each day
·         support for teachers and other staff to implement health promotion strategies and activities (e.g. professional development, capacity building activities)
·         parent support and home activities that encourage children to be more active, eat more nutritious foods and spend less time in screen based activities
However, study and evaluation designs need to be strengthened, and reporting extended to capture process and implementation factors, outcomes in relation to measures of equity, longer term outcomes, potential harms and costs.
Childhood obesity prevention research must now move towards identifying how effective intervention components can be embedded within health, education and care systems and achieve long term sustainable impacts.
Evaluation of a 2-year physical activity and healthy eating intervention in middle school children.
The aim of the present study was to evaluate the effects of a middle school physical activity and healthy eating intervention, including an environmental and computer-tailored component, and to investigate the effects of parental involvement. A random sample of 15 schools with seventh and eight graders was randomly assigned to one of three conditions: (i) intervention with parental involvement, (ii) intervention alone and (iii) control group. In 10 schools, an intervention, combining environmental changes with computer-tailored feedback, was implemented over 2 school years. In five intervention schools, increased parental support was added. Physical activity was measured with questionnaires in the total sample and with accelerometers in a sub-sample of children. Fat intake, fruit, water and soft drink consumption were measured using food-frequency questionnaires. Results showed significant positive intervention effects on physical activity in both genders and on fat intake in girls. Parental involvement did not increase intervention effects. It can be concluded that physical activity and eating behaviours of middle school children can be improved by school-based strategies combining environmental and personal interventions. The use of personalized computer-tailored interventions seems to be a promising tool for targeting adolescents but needs to be further explored.