Abstract / Summary
Introduction: The population-level double burden of malnutrition (DBM), characterized by the coexistence of undernutrition and overnutrition, presents a complex public health challenge. Xizang (Tibet), with its extreme high-altitude geography, rapid economic growth, and targeted school health policies, offers a unique context for nutritional transition, yet large-scale, repeated studies on the region’s DBM trends and multi-level associated factors remain scarce. Methods: Data were obtained from five large-scale cross-sectional surveys conducted in Xizang between 2019 and 2024 (except for 2022, when surveillance was not conducted), covering 301,242 participants aged 6–17 years. Nutritional status was defined using WHO growth standards for stunting, thinness, overweight, and obesity. Children and adolescents with stunting or thinness were classified as having undernutrition, while those with overweight or obesity were classified as having overnutrition. Prevalence was standardized across survey cycles—overall and within demographic, geographic, and socioeconomic strata—using multivariable logistic regression models to control for potential compositional variations. Multivariable mixed-effects models (MMEM) were used to analyze associations between potential correlates and the odds of undernutrition and overnutrition. Results: From 2019 to 2024, the standardized prevalence of undernutrition markedly decreased from 11.30% to 6.09%, driven primarily by stunting (9.42% to 4.12%). Overnutrition standardized prevalence peaked at 12.10% in 2020 (up from 9.42% in 2019), dipped to 11.24% in 2021, rebounded briefly to 11.44% in 2023, and fell to 10.00% in 2024. The standardized prevalence of undernutrition steadily increased with age and was consistently higher among boys, middle school students, and populations in rural, less developed, and high-altitude regions. Conversely, overnutrition decreased with age and predominated among girls, primary school students, and residents of urban, low-altitude, or moderately developed regions. Odds of undernutrition and overnutrition were significantly associated with a multi-level array of factors, including individual behaviors, school health management, socioeconomic status, altitude, and environmental variables. Conclusions: Xizang exhibits a unique “high-altitude DBM” pattern. The findings emphasize that public health strategies must integrate individual behavioral interventions with school-based health management and a nuanced understanding of environmental influences to effectively address the diverse nutritional needs of high-altitude populations.