Rates of youth obesity in the United States have more than tripled over the past three decades, with about a third of children and adolescents now categorized as obese, according to the Centers for Disease Control and Prevention. Some researchers have suggested that one of the possible contributing factors is the apparent problem of “food deserts” — impoverished neighborhoods where there is a perceived lack of access to fresh and healthful foods. While such problems clearly exist in certain neighborhoods, some researchers have critiqued the food desert hypothesis, while others have continued to explore it.

A 2012 study from the Public Policy Institute of California published in the Journal of Social Science and Medicine, “The Role of Local Food Availability in Explaining Obesity Risk among Young School-aged Children,” analyzed data from the Early Childhood Longitudinal Study, focusing on the kindergarten cohort from 1998 to 1999.

The study’s findings include:

• Children’s BMI increased over the time in elementary school, particularly for low-income children. Compared to their baseline in kindergarten, the average increase in BMI percentile was 4.76 points by fifth grade, but the increase for poor children was 7.01 points. Notably, “[among] minority and low-income sub-groups in particular, their weight gain is outpacing their height growth.”
• The higher rates of rapid weight increase among low-income children may not be related to access to healthy foods, however: “Children who live in high poverty neighborhoods have 0.77 supermarkets per square mile, compared to 0.41 in more affluent areas.”
• While “corner stores have significantly higher per-capita prevalence in poor and minority neighborhoods, and convenience stores per capita are larger in poor areas … more affluent and majority white neighborhoods have greater shares of fast-food chains within their retail food context.”
• Among the different types of food outlets (including supermarkets, corner stores and fast food restaurants), “increased convenience store exposure over time seems to have the largest positive association with upward shifts in BMI percentile.”

The researchers conclude that, “on average, the more salient food-availability issue facing most economically disadvantaged and minority communities in this national sample is not lack of access but rather ease of access.”

A related 2011 study published in the Archives of Internal Medicine, “Fast Food Restaurants and Food Stores,” also concluded that “adding neighborhood supermarkets may have little benefit to diet quality across the income spectrum and that alternative policy options such as targeting specific foods or shifting food costs (subsidization or taxation) should be further considered.” In other related research, a 2010 study from Duke University looks at the consequences of “food insecurity” for low-income women and its relationship with obesity among families. Further, a 2012 study in the journal PLoS One finds that there are strong peer influence effects in terms of obesity among networks of adolescents.

Tags: obesity, youth, children, poverty