Study designs of evaluations included in the review
Inclusion criteria were not defined in terms of the study design. The included studies were randomised controlled studies, non-randomised controlled trials and single-group pre-test post-test studies.
Specific interventions included in the review
Studies that assessed policy or environmental interventions to promote physical activity and/or good nutrition were eligible for inclusion. Studies had to describe the intervention to be included. The environment was defined as 'anything and everything outside the person', while environmental strategies were defined as those that involved changing the physical, social-cultural, economic or organisational systems to promote behaviour change. Studies that assessed educational strategies at the individual level but focused mainly on environmental strategies were eligible for inclusion. To be included in the review, studies had to report tests of interaction or moderation between the intervention studied and a second independent variable. Studies on the effects of media campaigns, determinants research, or individual-level interventions were excluded.
All of the included studies addressed interventions aimed at improving diet and/or physical activity and all were mainly school-based, although some incorporated paAll of the included studies addressed interventions aimed at improving diet and/or physical activity and all were mainly school-based, although some incorporated parental involvement or home-based activities and one included workplace interventions. The interventions in the included studies were school food service changes (including pricing change and changes in foods offered), family activity packets to be completed at home, daily activities to promote healthy food choices, teacher-led sessions on healthy eating and physical activity, and physical activities. The effect modifiers assessed included gender, race, age and site.rental involvement or home-based activities and one included workplace interventions. The interventions in the included studies were school food service changes (including pricing change and changes in foods offered), family activity packets to be completed at home, daily activities to promote healthy food choices, teacher-led sessions on healthy eating and physical activity, and physical activities. The effect modifiers assessed included gender, race, age and site.
Participants included in the review
Studies involving children or adolescents aged 3 to 18 years were eligible for inclusion. The included studies involved over 18,000 children from grades 1 through 6 (this corresponds roughly to ages 6 to 12).
Outcomes assessed in the review
Only studies measuring some behavioural outcome were eligible for inclusion. The outcomes assessed in the included studies were fruit and vegetable consumption, low-fat snack and milk sales, total energy intake, fat intake, cholesterol intake, sodium intake, and physical activity and fitness measures.
How were decisions on the relevance of primary studies made?
The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.
The authors stated that studies that met initial inclusion characteristics were reviewed independently by two reviewers to determine whether a test of moderation had been applied. Any differences between the reviewers were followed by a second assessment, though it was unclear what this involved.