To evaluate the effectiveness of school-based nutrition education in reducing or preventing overweight and obesity in children and adolescents. Systematic search in 14 databases and five systematic reviews for randomized controlled trials conducted in schools to reduce or prevent overweight in children and adolescents. Body mass index and fruit and vegetable intake were used as primary and secondary measures of outcome, respectively. There was no restriction by date of publication or language, except for languages with structured logograms. We excluded studies on specific populations presenting eating disorders, dyslipidemia, diabetes, and physical or mental disabilities, as well as studies that used drugs or food supplements as components of the intervention. The assessment by title and abstract and the quality assessment were performed independently by two researchers. We used the Centre for Reviews and Dissemination's guidance for undertaking reviews in health care and the software EPPI-Reviewer 3. From the initially retrieved 4,809 references, 24 articles met the inclusion criteria. The extracted data show that there is evidence of positive effects on anthropometry and of increase in fruit and vegetable consumption. Characteristics of the interventions that demonstrated effectiveness are: duration > 1 year, introduction into the regular activities of the school, parental involvement, introduction of nutrition education into the regular curriculum, and provision of fruits and vegetables by school food services. Interventions in schools to reduce overweight and obesity, as well as to increase fruits and vegetable consumption, have demonstrated effectiveness in the best-conducted studies.

This study reviewed the effectiveness of school-based physical activity interventions aimed at reducing overweight, obesity and hypertension in children. We searched 14 databases and analyzed studies published between April 2009 and September 2012. Only randomized controlled trials performed at the school level that included elements of physical activity but did not include nutritional co-interventions were analyzed. Studies were assessed by two recommended tools (EPHPP and GRADE), and the standardized mean differences with 95% confidence intervals were collected for a random-effect meta-analysis. A total of 12 papers were included in the meta-analysis, and these were divided according to three outcomes: body mass index (11 trials, n = 4,273, -0.02, 95% CI: -0.13 to 0.17, p = 0.8); body weight (5 trials, n = 1,330, -0.07, 95% CI: -0.18 to 0.04, p = 0.2); and blood pressure (6 trials, n = 1,549), including systolic (0.11, 95% CI: -0.10 to 0.31, p = 0.3) and diastolic pressure (-0.00, 95% CI: -0.10 to 0.10, p = 0.9). This meta-analysis of data from 11 randomized, school-based physical activity interventions suggests that, regardless of the potential benefits of physical activity in the school environment, the interventions did not have a statistically significant effect. However, it is difficult to generalize from these results because the duration, intensity and type of physical activity used in the interventions varied greatly.

OBJECTIVE To describe the methodological characteristics of the studies selected and assess variables associated with sedentary behavior in Brazilian children and adolescents. METHODS For this systematic review, we searched four electronic databases: PubMed, Web of Knowledge, LILACS, SciELO. Also, electronic searches were applied in Google Scholar. A supplementary search was conducted in the references lists of the included articles and in non-indexed journals. We included observational studies with children and adolescents aged from three to 19 years developed in Brazil, presenting analyses of associations based on regression methods and published until September 30, 2014. RESULTS Of the 255 potential references retrieved by the searches, 49 met the inclusion criteria and composed the descriptive synthesis. In this set, we identified a great number of cross-sectional studies (n = 43; 88.0%) and high methodological variability on the types of sedentary behavior assessed, measurement tools and cut-off points used. The variables most often associated with sedentary behavior were “high levels of body weight” (in 15 out of 27 studies; 55.0%) and “lower level of physical activity” (in eight out of 16 studies; 50.0%). CONCLUSIONS The findings of this review raise the following demands to the Brazilian agenda of sedentary behavior research geared to children and adolescents: development of longitudinal studies, validation of measuring tools, establishment of risk cut-offs, measurement of sedentary behavior beyond screen time and use of objective measures in addition to questionnaires. In the articles available, the associations between sedentary behavior with “high levels of body weight” and “low levels of physical activity” were observed in different regions of Brazil.