Monday, January 23, 2012

Food deserts linked to childhood obesity in rural Pennsylvania

Is obesity an epidemic? Is it genetic or related to environmental factors? Can obesity be disproportionately distributed across to the United States? These are the questions that researchers at the university of Pennsylvania set out to answer. What they find is that childhood obesity is positively linked to rural food deserts, indicating that obesity strongly relates to distributive inequalities.

Food deserts are formed in areas where access to food is limited by a lack of retail, full-service food stores. Rural areas, as opposed to urban areas, experience food deserts because low population density means that food store distribution is more dispersed where little to no public transportation is available. Rural areas are also at greater risk than urban areas of food desertification, a phenomenon of food system consolidation, where smaller, decentralized local food stores are replaced by urban centered, large-scale food stores. The prevalence of food deserts has been linked to socio-economic status and food insecurity, meaning that lower income neighborhoods have disproportionate access to retail food stores, in comparison to middle and high income neighborhoods. The lack of access results in food insecurity, defined by a lack of certainty of where your next food will come from. Likewise, the absence of retail food stores is often synonymous with the high presence of fast food restaurants or gas stations which carry cheaper high-caloric, low nutrient food, within distance of low-income residents, making access to less nutritious food relatively easy. Counter-intuitively, while low income residents are more likely to live in food deserts and experience greater incidence of food insecurity, they are also the communities most at risk for adult and childhood obesity because of the quality of food that they do have access to.

Researchers at the university of Pennsylvania conducted a study to see how food deserts influence the rates of childhood obesity using the growing technology of GIS (geographical information system), a computer program that allows researchers to use spatial data and socio-economic census data to draw conclusions about spatial relationships. Researchers used various data sources, including the 2000 Missouri Census for socio-economic data, the National Center for Education Statistics for school district information and Body Mass Index data from the Pennsylvania Department of Health for childhood obesity statistics. In the study, researcher’s mapped the Pennsylvania zip codes and calculated their proximity to food stores. Figure 1 overlaps the presence of food deserts with rural school districts, classifying food desert school districts as those where greater than 50% of the attending children lived in food desert zip codes. Food desert school districts contained children where more than 50% of the population lived in a food-desert district. The study found that close to 19% of rural school districts reside are also food desert school districts. Socio-economic data and child-hood obesity, as identified by the percentage of children with a BMI classified as overweight or obese, was compared in relation to attending a food desert school district versus a non-food desert school district. Researchers found statistical significance in the per capita and family income of food-desert districts. For example, median family income in a food desert school district averaged at 38,500 in comparison to 43,613. Similar trends occurred for rates of poverty, employment, education, infrastructure, and obesity. With trends of obesity, the childhood population living in a food desert was a statistically significant greater proportion of unhealthy weight when compared to those children living in non-food deserts. To understand the driving factors of childhood obesity in relation to socio-economic factors or the proximity to food stores, researchers ran statistical models to relate the percentage of obese students in a school district in relation to the percentage of students living in a food-desert, finding a statistically significant positive association between food deserts and childhood obesity. Meaning, children who live in food deserts are at higher risk for being overweight or obese and therefore, are at greater risk of the health hazards associated with poor weight management such as diabetes.


Spatial analysis relating the location of large grocery stores, zip codes and school districts. Food desert school districts make up 19% of all rural school districts in Pennsylvania and are positively correlated to childhood obesity.

The implications of this study show that childhood obesity may not necessarily be an epidemic, but rather, relates to the type of city and access to food. As such, childhood obesity affects rural and food-desert populations at greater rates than urban, non-food desert populations. This study demonstrated the use of GIS for modeling spatial inequalities, and points to the usefulness of geographical analysis to analyze patters of social injustice and distributive inequalities.



Vanessa Toro

Schafft, K.A., E.B. Jensen, and C.C. Hinrichs. 2009. Food Deserts and Overweight Schoolchildren: Evidence from Pennsylvani. Rural Sociology 74(2): 153-177

4 comments:

  1. I think that this is a great and really interesting study that could be used as an example of the preventative measures that need to be taken to avoid unhealthy lifestyles among children. Once we can identify the areas that are at high risk of problems such as childhood obesity, we can start targeting these areas for preventative care to help decrease the percentages. Education efforts are probably the best approach for childhood problems, such as obesity, because often times people just do not have the resources or knowledge to change their eating habits.

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  2. This is a really informative and well-written article. It's really interesting to consider that historically, poor populations had access to the fruit, veggies, and grains they grew themselves (before mass consumer grocery became the norm), and that obesity was a mark of wealth because you could afford to eat greasy, fatty, chef-prepared foods. It's a little ironic how those social symbols have changed. Using GIS to illustrate the correlations between obesity, food desert locations, and poverty made the data clear and easy to understand; it's an extremely useful tool to bring issues like this to a wider audience so that they can be addressed by informed individuals. I was not previously aware of this problem, but now I realize its significance and will be interested in the future to learn more. Thanks Vanessa!

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  3. I think that this article is most interesting because of the correlation between food DESERTS and childhood obesity. Before I read the entire article, I was rather confused and hesitant to believe that there could be any real correlation between the two. But the data seems sound, the use of GIS doesn't appear overtly manipulative, and the results are frankly rather sad.

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  4. I think mapping something like this with GIS is interesting. Personally I think this article leaves a lot of information out. IT says that food deserts are responsible or related to this but I'd like to see the information compared to physical activity. I think the rural areas adds distance to every trip so people are more likely to drive over walk. Kids don't ride there bikes with their friends because they don't have any close by. I guess like anything else, it's all in the way it is displayed.

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