Childhood obesity risk factors: an umbrella review of systematic reviews and meta-analyses

Introduction: Childhood obesity is one of the worldwide epidemics of the 21st century. The rising trend of complex genetic, environmental, psychological, and lifestyle factors has made addressing and managing the disease more complicated. Understanding the risk factors for childhood obesity is crucial for effective prevention, treatment, and the improvement of policy strategies. Aim: Given that many systematic reviews have been conducted about childhood obesity and overweight from different perspectives, this umbrella review of the systematic reviews and meta-analysis aims to comprehensively investigate a wide range of various risk factors associated with the obesity of children and young adults aged between 0 and 25 years old and their strength of association. This is a crucial step toward developing strategies for recognition, policy reform, and effective management of childhood overweight and obesity--an epidemic that has risen significantly over the years. Methods: A systematic literature search was conducted across Medline, Embase, Scopus, and Cochrane databases. 7867 results after removing the duplicates. The T&A screening was performed with the aid of ASReview by a machine learning algorithm, and 513 articles were selected. After full-text screening, 182 papers were excluded for wrong study design/outcome/outcome not stratified for pediatric age/ or not in English. After reviewing, 155 papers were selected for systematic review and meta-analysis. Results: The findings from the systematic review highlight that childhood obesity is caused by a wide range of different factors, including dietary, genetic, socioeconomic, environmental, parenting, behavioral, preconception, prenatal, perinatal, disease, and hormonal factors. The review also identifies and emphasizes the extent of association with these different factors and identifies which topics have been studied more extensively than others. Conclusion: Addressing the childhood overweight and obesity epidemic in our modern world requires a multi-faceted approach, as numerous contributing factors influence this disease. In this study, we aimed to identify as many contributing factors as possible to childhood overweight and obesity, particularly considering how our lifestyles transformed over the years. Comprehensive strategies are essential on a global scale to combat the childhood obesity epidemic. Strategies should include the promotion of healthy eating, physical activity, early diagnosis and management of associated diseases, and educational campaigns targeting families. Additionally, school policy reforms, screen time restrictions, and food marketing regulations aimed at children are crucial components of effective response.