Cooksey-Stowers Kristen, Schwartz Marlene B, Brownell Kelly D
Rudd Center for Food Policy and Obesity, University of Connecticut, Hartford, CT 06103, USA.
Sanford School of Public Policy, Duke University, Durham, NC 27708, USA.
Int J Environ Res Public Health. 2017 Nov 14;14(11):1366. doi: 10.3390/ijerph14111366.
This paper investigates the effect of food environments, characterized as food swamps, on adult obesity rates. Food swamps have been described as areas with a high-density of establishments selling high-calorie fast food and junk food, relative to healthier food options. This study examines multiple ways of categorizing food environments as food swamps and food deserts, including alternate versions of the Retail Food Environment Index. We merged food outlet, sociodemographic and obesity data from the United States Department of Agriculture (USDA) Food Environment Atlas, the American Community Survey, and a commercial street reference dataset. We employed an instrumental variables (IV) strategy to correct for the endogeneity of food environments (i.e., that individuals self-select into neighborhoods and may consider food availability in their decision). Our results suggest that the presence of a food swamp is a stronger predictor of obesity rates than the absence of full-service grocery stores. We found, even after controlling for food desert effects, food swamps have a positive, statistically significant effect on adult obesity rates. All three food swamp measures indicated the same positive association, but reflected different magnitudes of the food swamp effect on rates of adult obesity ( values ranged from 0.00 to 0.16). Our adjustment for reverse causality, using an IV approach, revealed a stronger effect of food swamps than would have been obtained by naïve ordinary least squares (OLS) estimates. The food swamp effect was stronger in counties with greater income inequality ( < 0.05) and where residents are less mobile ( < 0.01). Based on these findings, local government policies such as zoning laws simultaneously restricting access to unhealthy food outlets and incentivizing healthy food retailers to locate in underserved neighborhoods warrant consideration as strategies to increase health equity.
本文研究了以食物沼泽为特征的食物环境对成人肥胖率的影响。食物沼泽被描述为相对于更健康的食物选择而言，出售高热量快餐和垃圾食品的场所密度较高的区域。本研究考察了将食物环境分类为食物沼泽和食物荒漠的多种方法，包括零售食物环境指数的不同版本。我们合并了来自美国农业部（USDA）食物环境地图集、美国社区调查以及一个商业街参考数据集的食品店、社会人口统计学和肥胖数据。我们采用工具变量（IV）策略来校正食物环境的内生性（即个体自行选择居住社区，并且在决策时可能会考虑食物的可获得性）。我们的结果表明，食物沼泽的存在比没有提供全方位服务的杂货店更能预测肥胖率。我们发现，即使在控制了食物荒漠的影响之后，食物沼泽对成人肥胖率仍有正向的、具有统计学意义的影响。所有三种食物沼泽测量方法都表明了相同的正向关联，但反映了食物沼泽对成人肥胖率影响的不同程度（数值范围从0.00到0.16）。我们使用IV方法对反向因果关系进行调整后发现，食物沼泽的影响比单纯的普通最小二乘法（OLS）估计所得到的影响更强。在收入不平等程度较高的县（<0.05）以及居民流动性较低的县（<0.01），食物沼泽的影响更强。基于这些发现，诸如分区法之类的地方政府政策，同时限制进入不健康食品店并激励健康食品零售商在服务不足的社区选址，作为增加健康公平性的策略值得考虑。
