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.
Action Schools! BC: a school-based physical activity intervention designed to decrease cardiovascular disease risk factors in children.
Our primary objective was to determine whether a novel 'active school' model--Action Schools! BC--improved the cardiovascular disease (CVD) risk profile in elementary-school children. Our secondary objective was to determine the percentage of children with elevated CVD risk factors.
                We undertook a cluster-randomized controlled school-based trial with 8 elementary schools across 1 school year, in British Columbia, Canada, beginning in 2003. Boys and girls (n=268, age 9-11 years) were randomly assigned (by school) to usual practice (UP, 2 schools) or intervention (INT, 6 schools) groups. We assessed change between groups in cardiovascular fitness (20-m Shuttle Run), blood pressure (BP), and body mass index (BMI, wt/ht(2)). We evaluated total cholesterol (TC), total:high-density cholesterol (TC:HDL-C), low-density lipoprotein, apolipoprotein B, C-reactive protein and fibrinogen on a subset of volunteers (n=77).
                INT children had a 20% greater increase in fitness and a 5.7% smaller increase in BP compared with children attending UP schools (P<0.05). Forty five percent of children had at least one elevated risk factor (fitness, BP or BMI) at baseline. There were no significant differences between groups for change in BMI or in any of the blood variables.
                Action Schools! BC was an effective school-based physical activity model for improving the CVD risk profile of elementary-school children. Our multi-component intervention exposed children to fitness enhancing physical activity. It may be important for education stakeholders to adequately resource the delivery of the active school models if cardiovascular health benefits are to be achieved on a population basis.