The Effects of Physical Activity Together With Nutrition Programs in Educational Settings on Obesity and Overweight Reduction in Preschool Children: A Systematic Review of Randomized Controlled Trials

The first years of life are crucial to start preventive interventions that can have an impact on lifestyle and later overweight and obesity. Being obese during preschool years increases the likelihood of remaining obese as an adult and is associated with serious health conditions. Combined physical activity and nutritional interventions may produce synergistic effects on child development, but evidence from school-based programs is still limited. This systematic review investigated the impact of physical activity programs with simultaneous nutrition-related interventions in obese preschoolers. Methods: Systematic search across five databases (PubMed, ProQuest, SCOPUS, Web of Science, and SPORTDiscus) up to August 31, 2025. Randomized controlled trials examining combined in-preschool physical activity and nutrition-related interventions in preschool children recruited from educational settings were included. Methodological quality was rated using the RoB-2 scale. This systematic review was registered in PROSPERO. Conclusions: Combined preschool-based interventions integrating physical activity and nutrition show modest but consistent benefits in reducing BMI and improving dietary and behavioral outcomes in obese preschoolers. Family involvement and structural changes in the school environment appear to enhance effectiveness. Despite methodological limitations and heterogeneity across trials, evidence supports preschool years as a critical window for obesity prevention. Future studies should adopt standardized outcomes, longer follow-up, and cost-effectiveness analyses to inform large-scale implementation.