Randomized controlled trials on physical activity, diet, or both for public health through body weight management in 5- to 10-year-old pupils: a systematic review and meta-analysis.

Improving the quality of the most basic health behavior among youth may contribute to short-term body composition management with long-term implications for noncommunicable disease regression. This investigation aimed to assess the impact of primary school physical activity (PA), dietary, or dual approach interventions on pupils' body weight (BW) and body mass index (BMI). A systematic review and meta-analysis was completed following a study protocol and a trial registration (PROSPERO: CRD4202347770) with the PRISMA approach. Publications in English or German were included with school-based randomized controlled trials on diet and/or PA. Pupils of primary schools (aged 5-10) with no major nutritional deficiency or unstable health condition were included. The Boolean search strategy revealed a total of 9479 articles, qualifying 39 studies with 20 462 pupils (including 10 211 girls and 10 251 boys) for quantitative synthesis. The interventions were mostly PA (n = 31), several were dietary (n = 6), and some were dual approach (n = 5). Random effects meta-analyses revealed PA intervention (n = 20) to have an effect size of +0.07 kg (95% CI: -0.01 to 0.15) and -0.12 kg/m2 (95% CI: -0.23 to -0.01). Low statistical heterogeneity was found for BW (I2 = 0%; P = 1.000) and BMI (I2 = 0%; P = .9688), respectively. The findings indicate a scarcity of top-quality scientific research performed on healthy diet for body weight management in primary schools. PA intervention for elementary school pupils provides support for a healthier body composition profile amidst the current world health crisis.