Childhood obesity rates in the United States have more than tripled since 1982, and “poor eating habits” tops the American Academy of Child and Adolescent Psychiatry’s 2011 list of the reasons why. It is also a major impetus behind the White House Childhood Obesity Task Force and First Lady Michelle Obama’s “Let’s Move” initiative; the USDA even offers a food desert locator organized by census tract.

The prevalent theory is that limited access to healthful food may encourage poor eating habits, particularly among low-income families; two 2012 studies outlined below challenge that assumption.

The first 2012 study, by the RAND Corporation published in the American Journal of Preventive Medicine, “School and Residential Neighborhood Food Environment and Diet Among California Youth,” examined the relationship between local food options and the diets of California youth. The researchers analyzed data on 8,226 children (age 5 to 11 years) and 5,236 adolescents (age 12 to 17 years) from the 2005 and 2007 California Health Interview Surveys (CHIS), as well as self-reports of daily diets, BMI (body mass index) calculations and demographic information.

Key study findings include:

• The proximity of stores selling healthful food was limited for most study participants; 70% of families with children had no supermarkets within a half mile of home. Approximately 7% of participating families lived within a half mile of two or more supermarkets.
• The distance to fast food restaurants varied widely across the sample. While “45% of adolescents had no fast food restaurants in 10-minute walking distance, 28% had three or more in proximity from school.”
• The BMI of students was more closely related to gender, age, and their parents’ BMI than proximity to healthy food options. “Boys tend to consume less vegetables and fruits but more milk, fast food and soda than girls.”
• While adolescents typically consumed “considerably more soda, high sugar foods, and fast food” than their younger counterparts, the intake rates of juice, fruits and vegetables were approximately the same for both groups.
• Overall, the study “found no evidence to support the hypotheses that improved access to supermarkets, or less exposure to fast food restaurants or convenience stores within walking distance, improves diet quality or reduces BMI among Californian youth.”

The researchers noted that “access to transportation could be a more essential determinant of dietary behaviors than immediate availability,” and that only 3% of households in the 2007 CHIS survey did not have access to a car. (In a related study from 2006, researchers in Los Angeles found that fewer than 20% of respondents shopped only in their local neighborhoods.

The second 2012 study, from Public Policy Institute of California and published in Social Science & Medicine, “The Role of Local Food Availability in Explaining Obesity Risk Among Young School-Aged Children,” found that, while children who lived in poor and minority neighborhoods had ample access to fast-food outlets and convenience stores, they also had access to other types of food outlets such as large-scale grocery stores and casual dining establishments not linked to obesity risks. In fact, the researcher found more fast-food dining outlets per square mile and per capita in majority white and non-poor areas. “This is not to say that food deserts are non-existent. The findings documented here do suggest 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.”

Tags: youth, nutrition, children, California