Major risk factors of obesity in China and recommendations for future prevention and control efforts: a systematic review and meta-analysis.

Background: Despite increasing national efforts, the prevalence of overweight and obesity among Chinese adults reached 57%, suggesting a disconnect between the drivers and current intervention. This study aims to identify the multilevel risk factors and evaluate existing policy strategies, to inform more effective, evidence-based interventions. Methods: We projected national overweight and obesity trends for 2030 and 2035 using surveillance data. We systematically searched China National Knowledge Infrastructure, Wanfang Data, SinoMed, PubMed, Web of Science, and Scopus, for cohort, case-control, and/or cross-sectional studies published from Jan 1, 2000, to Oct 1, 2024. Studies addressing determinants of overweight, obesity, and central obesity in the Chinese population were included; meta-analyses were performed where appropriate. Expert consultations supplemented evidence on meso- and macro-level determinants. National policies on obesity prevention and control were reviewed. Findings: The prevalence of overweight and obesity in China was projected to reach 72.2% (95% confidence interval [CI] 69.7%-74.7%) for adults and 41.9% (37.4%-46.1%) for children/adolescents by 2035. In total 1512 studies identified, with 873 eligible for meta-analysis, including 322 studies on adults (21,566,496 individuals). We identified 17 risk factors for adult overweight and obesity, with individual-level behavioral factors being most prevalent. These included higher red meat intake (odds ratio 2.28, 95% CI 1.07-4.82), rapid eating speed (2.04, 1.35-3.08), higher sugar-sweetened beverages intake (1.90, 1.10-3.29), higher red and white meat intake (1.54, 1.11-2.14), meat preference (1.51, 1.03-2.22), alcohol consumption (1.23, 1.15-1.31), higher percentage of energy from fat (1.22, 1.14-1.31), lower physical activity (1.24, 1.02-1.51) and shorter nocturnal sleep duration (1.09, 1.03-1.15). Additional risk factors for central obesity included lower adherence to a "traditional Chinese dietary pattern" (1.57, 1.08-2.27), higher adherence to a "modern dietary pattern" (1.34, 1.05-1.71), higher spicy food intake (1.19, 1.05-1.36), higher staple food intake (1.18, 1.05-1.33), lower fruit intake (1.12, 1.02-1.23), longer sitting time (1.24, 1.09-1.41) and screen time (1.09, 1.05-1.14). For children and adolescents, 26 risk factors for overweight and obesity, and three for central obesity were identified, and 18 for macrosomia in neonates. Expert consultation emphasized importance of environmental and policy-level factors, especially food environment. Policy analysis revealed critical gaps in existing framework, including limited multisectoral collaboration, weak regulatory frameworks, lack of life-course-specific interventions, inadequate focus on high-risk populations (e.g., postmenopausal women), and limited evidence-based policymaking. Interpretation: The obesity epidemic in China is driven by a complex interplay of individual, environmental, and systemic factors. Effective, comprehensive, government-led strategies are urgently needed to address both individual risk factors and broader obesogenic environments through coordinated and evidence-based actions. Funding: This work was supported by the Chinese National Science and Technology Innovation 2030, Noncommunicable Chronic Diseases-National Science and Technology Major Project (Grant No. 2023ZD0508500, 2023ZD0508504).