The trend of prevalence and severity of the overweight problem in young children, reduces the general quality of the future population to a certain extent, inducing a great risk to the sustainable development of health human capital stock in China.

To scientifically understand the spatio-temporal evolutionary patterns and future development trends of overweight rates among children under 5 in China, in order to provide support for controlling overweight in children, improve the efficiency of local governance and support for the implementation of precise interventions.

In April 2022, the 5 km×5 km gridded dataset in 105 middle-and low-income countries provided by the Institute for Health and Evaluation at the University of Washington (IHME) was used as the data source to extract the gridded data of overweight rates among children under 5 in China (excluding Hong Kong Special Administrative Region, Macao Special Administrative Region and Taiwan District) from 2000 to 2019 in this study. The average overweight rate of children under 5 from 2000 to 2019 was calculated pixel-to-pixel, the Theil-Sen estimator, Mann-Kendall test and Hurst index estimation method was used to characterize the spatio-temporal evolutionary patterns and future development trends among children under 5 pixel-to-pixel.

Overweight among children under 5 is more prevalent in most regions of Shandong Province, Hunan Province and local regions of Fujian Province, Guangdong Province, Hainan Province, Beijing Municipality and Tianjin Municipality during the 20-year period from 2000 to 2019, with the average overweight rate of children under 5 in Hunan Province reaching 29.42%. The area of the regions with significant increase in overweight rates among children under 5 accounts for 60.59% of the total area of the regions in the study (excluding regions with missing data) . The area of the central and eastern regions with a significantly increasing trend in the overweight rates among children under 5 accounts for a higher proportion of the total area of central and eastern regions (excluding regions with missing data) than the proportion accounted by the area of the western regions with a significantly increasing trend in the overweight rates among children under 5 of the total area of western regions (excluding regions with missing data) . The area of the regions with no significant change in the evolution trend of overweight rates accounts for 25.33% of the total area of the regions in the study, which is scattered in patches in parts of provinces, such as cities cluster in the middle reaches of the Yangtze River urban agglomeration. The area of the regions with significant change in the evolution trend of overweight rates accounts for 14.08% of the total area of the regions in the study, concentrated in some regions in the Xinjiang Uygur Autonomous Region, Qinghai Province, Sichuan Province and Yunnan Province in the west of China, and local regions of Hebei Province, Liaoning Province and Shandong Province in the east of China. According to the Hurst index, the area of the regions with persistent or trend-enhancing characteristics of the time series of overweight rates of children under 5 accounts for 84.87% of the total area of the regions in the study.

The spatial heterogeneity of overweight rates among children under 5 in China is obvious. There is a synergistic "U"-shaped association between the overweight rates of children under 5 and the overall level of regional development, the association implies a multi-stage, cascading developmental process of "declining stage of stunting" "stabilization stage" "rising stage of overweight with overnutrition". Focusing on social problems derived from the coupling of multidimensional factors of overweight in young children, the results of the study provide scientific support and policy reference for the government to formulate region-specific policies, build a three-level governance network of "government policy regulation - social concept penetration - family health management", and scientifically and precisely solve the overweight problem among children under 5.

低龄儿童超重问题呈现普遍化、严重化的趋势在一定程度上降低了未来人口素质，给中国健康人力资本存量的可持续发展带来巨大风险。

科学认识中国5岁以下儿童超重率的时空演变模式与未来发展趋势，旨在为控制儿童超重现象、提升地方政府治理效能、实施精准的干预措施提供支持。

于2022年4月，以华盛顿大学卫生计量与评估研究所提供的全球105个中低收入国家5 km×5 km格网数据集作为数据源，提取2000—2019年中国（除香港特别行政区、澳门特别行政区、台湾地区）5岁以下儿童超重率5 km×5 km格网数据，逐像元计算2000—2019年平均5岁以下儿童超重率，使用泰尔森估算法、Mann-Kendall检验法与Hurst指数估计法，逐像元对5岁以下儿童超重率的时空演变模式与未来发展趋势进行刻画。

2000—2019年20年间，5岁以下儿童超重情况在山东省、湖南省的大部分地区及福建省、广东省、海南省、北京市、天津市等省份的局部地区较为普遍，其中湖南省全省的平均5岁以下儿童超重率达29.42%；5岁以下儿童超重率明显增长的地区面积占研究区总面积（不含数据缺失区域）的60.59%，中部与东部地区5岁以下儿童超重率呈明显增长趋势的面积占中部与东部地区总面积（不含数据缺失区域）的比例高于西部地区5岁以下儿童超重率呈明显增长趋势的面积占西部地区面积（不含数据缺失区域）的比例；超重率演变趋势无明显变化的地区面积占研究区总面积的25.33%，从空间分布上看，以斑块状散布在各省份的部分地区，如长江中游城市群等；超重率演变呈明显降低趋势的地区面积占研究区总面积的14.08%，集中于西部地区的新疆维吾尔自治区、青海省、四川省、云南省等省份的部分地区，以及东部地区的河北省、辽宁省、山东省的局部区域。根据Hurst指数，5岁以下儿童超重率时间序列具有持久性或趋势增强特征的地区面积占研究区总面积的84.87%。

中国5岁以下儿童超重率空间分异特征明显。5岁以下儿童超重率与地区发展整体水平存在着协同的"U"型关联，这种关联背后蕴含着"发育迟缓超重现象下降期""超重现象平稳期""营养过剩超重现象上升期"这一多阶段、串联式的发展过程。针对低龄儿童超重这一多维因素耦合衍生出的社会问题，研究结果为政府制定区域政策、构建"政府政策调控-社会理念渗透-家庭健康管理"三级联动的治理网络、科学精准地解决儿童超重问题提供了科学支撑与政策参考。