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.
Evaluating the effect of nutritional education on the prevalence of overweight/obesity and on foods eaten at primary schools.
To assess the effects of a nutritional education program on the prevalence of overweight/obesity and on the foods eaten by schoolchildren in the 2nd grade of primary education.
                The sample was made up of 135 schoolchildren, recruited from one private and one public school in Florianópolis, Brazil, and allocated to either an intervention group (n = 55) or a no-intervention group (n = 80). The children underwent two anthropometric assessments and two dietary intake assessments, before and after attending a nutritional education program. The program consisted of eight fortnightly meetings and covered subjects related to healthy diets, how to make healthy snacks, and physical activity. Nutritional status was classified according to body mass index for age, using the Centers for Disease Control and Prevention growth charts as reference, and the foods the children ate at school were classified according to the Santa Catarina School Canteens Act. Data were analyzed using the Statistical Package for the Social Sciences, and values of p <or= 0.05 were defined as significant.
                The percentage of overweight/obese schoolchildren increased from 21.8 to 23.6% in the intervention group and from 33.7 to 35.0% in the no-intervention group (p > 0.05). The intervention group significantly (p = 0.013) reduced its intake of artificial juice, which is prohibited by the Act. In the no-intervention group, there was a significant increase in intake of prohibited foods, such as mass-produced snacks (p = 0.021) and soda (p = 0.031). Furthermore, the intake of breakfast cereal, which is appropriate for eating at school, decreased (p = 0.039).
                Despite its short duration, after attending the nutritional education program, there were improvements in the quality of the food the schoolchildren were eating.