近年来我国儿童超重肥胖率呈现快速上升趋势，超重肥胖已成为威胁我国儿童身心健康的重要公共卫生问题。2020年国家卫生健康委等六部门联合印发的《儿童青少年肥胖防控实施方案》指出要“建设肥胖防控支持性环境，有效遏制超重肥胖流行”。学校周边食物环境是学校食物环境的重要组成部分，我国学校周边食物环境是何种状况、我国学校周边食物环境对儿童肥胖有怎样的影响，是目前儿童超重肥胖防控支持性环境研究中亟需解决的关键问题。

本研究基于已有研究中食物环境评价指标，结合高德地图兴趣点分类编码，确定纳入我国学校周边食物环境评价的食品店铺类别，包括食品零售和餐饮服务两大类共7小类，食品零售大类下包括便利店、超市和菜市场；餐饮服务大类下包括快餐店、中餐厅、外国餐厅和甜品店。结合文献研究及GIS最小邻近距离分析结果，确定了学校周边200米、800米、1200米和1500米4级学校周边缓冲区。基于地理信息系统技术，利用高德地图应用程序接口获取覆盖我国31个省份、261个市（区/县）行政区划范围内的食品零售和餐饮服务店铺兴趣点数据，利用ArcGIS平台对数据进行处理和空间分析，获得纳入研究的1309所学校周边4级缓冲区范围内的便利店、超市、菜市场、快餐店、中餐厅、外国餐厅和甜品店的数量数据，在此基础上从店铺数量、富集程度和构成特征三个层面分析我国学校周边食物环境总体状况，比较学校周边食物环境的城乡差异、东中西差异和各省之间的差异，探索我国儿童超重肥胖不同流行水平地区之间学校周边食物环境的差异，并分别通过有序logit回归模型和多元线性回归模型分析学校周边食物环境与儿童超重肥胖流行水平和儿童肥胖率的相关关系。本研究采用SAS 9.4软件进行统计学分析。

研究发现：1. 我国学校周边食物环境总体状况：我国学校周边200米范围内的食品零售和餐饮服务店铺数量很少，纳入研究的学校中有51.8%的学校食品零售和餐饮服务店铺数量为0。我国学校周边800米范围内的食品零售和餐饮服务店铺数量的中位数分别为16个（P₂₅~P₇₅：4~48个）和37（P₂₅~P₇₅：7~136个）；学校周边1200米范围内的食品零售和餐饮服务店铺数量的中位数分别为32个（P₂₅~P₇₅：7~93个）和77个（P₂₅~P₇₅：16~272个）， 学校周边1500米范围内的食品零售和餐饮服务店铺数量的中位数分别为48个（P₂₅~P₇₅：8~130个）和113个（P₂₅~P₇₅：18~377个）。在学校周边800米、1200米和1500米范围内90%以上的学校均至少有1个食品店铺，42%以上的学校周边食物环境由7类商铺构成，66%以上的学校周边食物环境构成中至少同时含有“便利店”、“超市”、“菜市场”、“快餐店”和“中餐厅”这5个类店铺。

2. 我国城乡、东中西部及各省之间学校周边食物环境存在显著地区差异：在学校周边800米、1200米和1500米范围内，城市地区的学校明显比农村地区有更多食品零售和餐饮服务店铺（P<0.001）；城市地区周边有食品零售和餐饮服务店铺的学校占比、有5种以上食品店铺的学校占比、至少同时有“便利店”“超市”“菜市场”“快餐店”和“中餐厅”这5个类食品店铺的学校占比均明显高于农村地区（P<0.001）。东部地区学校周边800米范围内明显比中西部地区有更多的食品零售店铺（P<0.01），东部地区学校周边1200米和1500米范围内明显比中西部地区有更多的食品零售和餐饮服务店铺（P<0.01）；东部地区在周边800米和1500米范围内既有食品零售、又有餐饮服务店铺的学校占比明显比中部地区更多（P<0.05）；东部地区在周边800米、1200米、1500米范围内有5种以上食品店铺类别的学校占比明显比中西部地区更多（P<0.01）；东部地区在周边800米、1200米、1500米范围内至少同时有“便利店”、“超市”、“菜市场”、“快餐店”和“中餐厅”这5类食品店铺的学校占比明显比中部地区更多（P<0.05）。以省/市/自治区为单位的统计结果显示，东北和华北各省学校周边食品零售和餐饮店铺数量较多，西北和西南地区数量相对较少。与其他各省相比，北京、辽宁、陕西、上海、福建和广东学校周边食品零售和餐饮服务店铺的数量均相对较多。

3. 我国学校周边食物环境与儿童超重肥胖的关系：我国儿童青少年超重肥胖高流行水平地区的学校在周边800米、1200米、1500米范围内的超市、菜市场和外国餐厅数量，在学校周边1200米和1500米范围内快餐店和中餐厅的数量以及学校周边1200米和1500米范围内食品店铺的富集程度均明显高于中、低流行水平地区（P<0.05）。有序logit回归模型结果显示，学校周边1500米范围内的超市数量越多，儿童超重肥胖流行水平越高；学校周边1200米范围内店铺富集程度越高，儿童超重肥胖流行水平越低。多元线性回归模型结果显示，学校周边1500米范围内的超市和菜市场数量与儿童肥胖率呈正相关关系。

本研究建立了基于地理信息系统技术和大数据技术评价我国学校周边食物环境的方法，该方法科学有效，能够解决传统问卷调查耗时长、成本高的问题，对于食物环境相关研究具有重要的参考价值；研究首次较为全面地描述了我国学校周边食物环境状况，并比较了我国学校周边食物环境的城乡差异、东中西部地区差异和各省之间的差异；研究首次从宏观尺度探索我国学校周边食物环境与儿童超重肥胖的关系，并发现学校周边食物环境与儿童超重肥胖流行水平和儿童肥胖率之间存在显著的相关关系。在未来研究中，亟待对学校周边食物环境和儿童肥胖关系做更为深入的探索。

The rate of childhood overweight and obesity had increased rapidly in China and had become a threat to children and adolescent health. The National Health Commission of the People’s Republic of China along with other five departments issued the "Implementation Plan for the Prevention and Control of Obesity in Children and Adolescents" in 2020, pointed out that. The plan calls for "building supportive environments to prevent and control the obesity epidemic". As an important component of school food environment, the food environment around schools and its impacts on childhood obesity should be focused and analyzed.

This study has formulated the quantitative indicators of Chinese School Neighbourhood Food Environment (SNFE) based on the food outlests described in the published research and the Amap point of interest (POI) classification code. Two kinds of food outlets including food retail and catering service stores were analysized to quantify SNFEs. The food retail stores include convenience stores, supermarkets and wet markets. The catering service stores include fast food restaurants, Chinese restaurants, foreign restaurants and dessert shops. Four-level distance ranges of 200 meters, 800 meters, 1200 meters and 1500 meters around the school were selected for buffer zones analysis. Based on Geographic Information System (GIS) technology, the POI data of food retail and catering service stores within the administrative division of 261 cities (districts/counties) among 31 provinces of China were obtained by using AMAP Application Program Interface (API). ArcGIS platform was used to conduct data process and spatial analysis and the number of convenience stores, supermarkets, wet markets, fast food restaurants, Chinese restaurants, foreign restaurants and dessert shops in the 4-level buffer zones around 1309 schools included in the study were obtained. The number of shops, enrichment degree and composition were analyzed as the three parts of the overall characteristics of SNFE. Differences of SNFEs between urban and rural, among different areas and provinces were compared and differences of SNFEs among different areas of overweight and obesity prevalence among Chinese children and adolescents were explored. Ordered logit regression model and multiple linear regression model were established to analysis the influence of SNFEs on children overweight obesity epidemic levels and the obesity rate, respectively. SAS 9.4 was used for statistical analysis.

The study found: (1) The overall characteristics of SNFE in China are as follows: there are few food retail and catering service stores within 200 meters buffer zone. 51.8% of the studied schools have no food retail and catering service stores. The median of food retail and food service stores within 800 meters of schools in China is 16 (P₂₅~ P₇₅: 4~48) and 37 (P₂₅~ P₇₅: 7~136), respectively. The median of food retail and food service stores within 1200 meters of the school is 32 (P₂₅~ P₇₅: 7~93) and 77 (P₂₅~ P₇₅: 16~272), respectively. The median of food retail and food service stores within 1500 meters of the school is 48 (P₂₅~ P₇₅: 8~130) and 113 (P₂₅~ P₇₅: 18~377), respectively. Within 800 meters, 1200 meters and 1500 meters around shchools, more than 90% of the schools have at least one food retail or catering service stores, more than 42% of the schools’ SNFE is composed of seven types of stores, and more than 66% of the schools’ SNFE contains at least convenience store, supermarket, wet market, fast food restaurant and Chinese restaurant.

(2) Significant differences of SNFEs are found between urban and rural areas and among east, middle and west regions and among provinces: Within 800 meters, 1200 meters and 1500 meters buffer zones, schools in urban areas have significantly more food retail and catering service stores than those in rural areas (p<0.001). The proportion of schools with both food retail and catering service stores in urban areas is significantly higher than that in rural areas (p<0.001). The proportion of schools with more than 5 kinds of food retail or catering service stores in urban areas is significantly higher than that in rural areas (p<0.001). The proportion of schools with at least convenience store, supermarket, wet market, fast food restaurant and Chinese restaurant simultaneously in the vicinity of urban areas is significantly higher than that of rural areas (p<0.001). There are more food retail stores within 800 meters of schools in the eastern region than that in the central and western regions (p<0.01). There are more food retail and food service stores within 1200 meters and 1500 meters of schools in the eastern region than that in the central and western regions (p<0.01). The proportion of schools with both food retail and catering service stores within 800 meters and 1500 meters in the eastern region is significantly higher than that in the central region (p<0.05). Within 800 meters, 1200 meters and 1500 meters buffer zones, the proportion of schools with more than five kinds of food retail or catering service stores in the eastern region is significantly higher than that in the central and western regions (p<0.01). Within 800 meters, 1200 meters and 1500 meters the proportion of schools with at least convenience store, supermarket, wet market, fast food restaurant and Chinese restaurant simultaneously in the eastern region is significantly higher than that in the central region (p<0.05). According to the statistical results of provinces/cities/autonomous regions, there are more food retail and catering service stores around schools in northeast and north China, while the number in northwest and southwest regions is relatively less. food retail and catering service stores around schools in Beijing, Liaoning, Shaanxi, Shanghai, Fujian and Guangdong provinces are relatively higher.

 (3) The relationships between SNFEs and childhood obesity are as follows: In areas with high prevalence of overweight and obesity among children and adolescents in China, there are more supermarkets, wet markets and foreign restaurants within 800 meters, 1200 meters and 1500 meters around schools, more fast food restaurants and Chinese restaurants and higher enrichment degree of food retail or catering service stores within 1200 meters and 1500 meters compared with the middle and low epidemic areas (p<0.05). The result of orderd logit regression model shows that the more supermarkets within 1500 meters of the schools, the higher the prevalence of overweight and obesity among children. The higher the store enrichment level within 1200 meters around the schools, the lower the prevalence of overweight and obesity in children. The result of multiple linear regression model shows that the numbers of supermarkets and wet markets within 1500 meters of the school are positively correlated with the rate of childhood obesity.

This study established a scientific and effective method to evaluate the SNFEs based on GIS and Big Data technology. The method can solve the problems of long time and high cost in traditional questionnaire survey, and has important reference value for food environment related research. This paper comprehensively describes the surrounding food environment of Chinese schools for the first time, and compares the differences of the SNFEs between urban and rural areas, eastern and western regions and provinces. This study explores the relationship between SNFEs and childhood overweight and obesity for the first time from the macro scale, and finds that there are significant differences in SNFEs between different prevalence levels of overweight and obesity in children and between childhood obesity rate. It is urgent to explore the relationship between SNFEs and childhood obesity in the future. 

The rate of childhood overweight and obesity had increased rapidly in China and had become a threat to children and adolescent health. The National Health Commission of the People’s Republic of China along with other five departments issued the "Implementation Plan for the Prevention and Control of Obesity in Children and Adolescents" in 2020, pointed out that. The plan calls for "building supportive environments to prevent and control the obesity epidemic". As an important component of school food environment, the food environment around schools and its impacts on childhood obesity should be focused and analyzed.

This study has formulated the quantitative indicators of Chinese School Neighbourhood Food Environment (SNFE) based on the food outlests described in the published research and the Amap point of interest (POI) classification code. Two kinds of food outlets including food retail and catering service stores were analysized to quantify SNFEs. The food retail stores include convenience stores, supermarkets and wet markets. The catering service stores include fast food restaurants, Chinese restaurants, foreign restaurants and dessert shops. Four-level distance ranges of 200 meters, 800 meters, 1200 meters and 1500 meters around the school were selected for buffer zones analysis. Based on Geographic Information System (GIS) technology, the POI data of food retail and catering service stores within the administrative division of 261 cities (districts/counties) among 31 provinces of China were obtained by using AMAP Application Program Interface (API). ArcGIS platform was used to conduct data process and spatial analysis and the number of convenience stores, supermarkets, wet markets, fast food restaurants, Chinese restaurants, foreign restaurants and dessert shops in the 4-level buffer zones around 1309 schools included in the study were obtained. The number of shops, enrichment degree and composition were analyzed as the three parts of the overall characteristics of SNFE. Differences of SNFEs between urban and rural, among different areas and provinces were compared and differences of SNFEs among different areas of overweight and obesity prevalence among Chinese children and adolescents were explored. Ordered logit regression model and multiple linear regression model were established to analysis the influence of SNFEs on children overweight obesity epidemic levels and the obesity rate, respectively. SAS 9.4 was used for statistical analysis.

The study found: (1) The overall characteristics of SNFE in China are as follows: there are few food retail and catering service stores within 200 meters buffer zone. 51.8% of the studied schools have no food retail and catering service stores. The median of food retail and food service stores within 800 meters of schools in China is 16 (P₂₅~ P₇₅: 4~48) and 37 (P₂₅~ P₇₅: 7~136), respectively. The median of food retail and food service stores within 1200 meters of the school is 32 (P₂₅~ P₇₅: 7~93) and 77 (P₂₅~ P₇₅: 16~272), respectively. The median of food retail and food service stores within 1500 meters of the school is 48 (P₂₅~ P₇₅: 8~130) and 113 (P₂₅~ P₇₅: 18~377), respectively. Within 800 meters, 1200 meters and 1500 meters around shchools, more than 90% of the schools have at least one food retail or catering service stores, more than 42% of the schools’ SNFE is composed of seven types of stores, and more than 66% of the schools’ SNFE contains at least convenience store, supermarket, wet market, fast food restaurant and Chinese restaurant.

(2) Significant differences of SNFEs are found between urban and rural areas and among east, middle and west regions and among provinces: Within 800 meters, 1200 meters and 1500 meters buffer zones, schools in urban areas have significantly more food retail and catering service stores than those in rural areas (p<0.001). The proportion of schools with both food retail and catering service stores in urban areas is significantly higher than that in rural areas (p<0.001). The proportion of schools with more than 5 kinds of food retail or catering service stores in urban areas is significantly higher than that in rural areas (p<0.001). The proportion of schools with at least convenience store, supermarket, wet market, fast food restaurant and Chinese restaurant simultaneously in the vicinity of urban areas is significantly higher than that of rural areas (p<0.001). There are more food retail stores within 800 meters of schools in the eastern region than that in the central and western regions (p<0.01). There are more food retail and food service stores within 1200 meters and 1500 meters of schools in the eastern region than that in the central and western regions (p<0.01). The proportion of schools with both food retail and catering service stores within 800 meters and 1500 meters in the eastern region is significantly higher than that in the central region (p<0.05). Within 800 meters, 1200 meters and 1500 meters buffer zones, the proportion of schools with more than five kinds of food retail or catering service stores in the eastern region is significantly higher than that in the central and western regions (p<0.01). Within 800 meters, 1200 meters and 1500 meters the proportion of schools with at least convenience store, supermarket, wet market, fast food restaurant and Chinese restaurant simultaneously in the eastern region is significantly higher than that in the central region (p<0.05). According to the statistical results of provinces/cities/autonomous regions, there are more food retail and catering service stores around schools in northeast and north China, while the number in northwest and southwest regions is relatively less. food retail and catering service stores around schools in Beijing, Liaoning, Shaanxi, Shanghai, Fujian and Guangdong provinces are relatively higher.

 (3) The relationships between SNFEs and childhood obesity are as follows: In areas with high prevalence of overweight and obesity among children and adolescents in China, there are more supermarkets, wet markets and foreign restaurants within 800 meters, 1200 meters and 1500 meters around schools, more fast food restaurants and Chinese restaurants and higher enrichment degree of food retail or catering service stores within 1200 meters and 1500 meters compared with the middle and low epidemic areas (p<0.05). The result of orderd logit regression model shows that the more supermarkets within 1500 meters of the schools, the higher the prevalence of overweight and obesity among children. The higher the store enrichment level within 1200 meters around the schools, the lower the prevalence of overweight and obesity in children. The result of multiple linear regression model shows that the numbers of supermarkets and wet markets within 1500 meters of the school are positively correlated with the rate of childhood obesity.

This study established a scientific and effective method to evaluate the SNFEs based on GIS and Big Data technology. The method can solve the problems of long time and high cost in traditional questionnaire survey, and has important reference value for food environment related research. This paper comprehensively describes the surrounding food environment of Chinese schools for the first time, and compares the differences of the SNFEs between urban and rural areas, eastern and western regions and provinces. This study explores the relationship between SNFEs and childhood overweight and obesity for the first time from the macro scale, and finds that there are significant differences in SNFEs between different prevalence levels of overweight and obesity in children and between childhood obesity rate. It is urgent to explore the relationship between SNFEs and childhood obesity in the future.