摘要：Objectives. We examined the concentration of fast food restaurants in areas proximal to schools to characterize school neighborhood food environments. Methods. We used geocoded databases of restaurant and school addresses to examine locational patterns of fast-food restaurants and kindergartens and primary and secondary schools in Chicago. We used the bivariate K function statistical method to quantify the degree of clustering (spatial dependence) of fast-food restaurants around school locations. Results. The median distance from any school in Chicago to the nearest fast-food restaurant was 0.52 km, a distance that an adult can walk in little more than 5 minutes, and 78% of schools had at least 1 fast-food restaurant within 800 m. Fast-food restaurants were statistically significantly clustered in areas within a short walking distance from schools, with an estimated 3 to 4 times as many fast-food restaurants within 1.5 km from schools than would be expected if the restaurants were distributed throughout the city in a way unrelated to school locations. Conclusions. Fast-food restaurants are concentrated within a short walking distance from schools, exposing children to poor-quality food environments in their school neighborhoods. Over the past 3 decades, fast-food retail sales in the United States have soared 900%, from $16.1 billion in 1975 to a projected $153.1 billion in 2004. 1 The number of fast-food restaurants in the country now exceeds 280000. 2 In this same period, Americans have become increasingly dependent on restaurants and fast-food chains for their meals, 3 with almost half of US food spending going toward food eaten away from home. 4 The fast-food industry markets heavily to children and adolescents, who make up an important part of the industry’s consumer base. 5 , 6 Among youths aged 12 to 18 years, the percentage of total energy intake consumed from fast-food and other restaurants has increased from 6.5% in 1977–1978 to 19.3% in 1994–1996. 3 On a typical day, almost a third of children and adolescents eat fast food. 7 Portion sizes and the corresponding caloric content of foods served at fast-food restaurants have also increased appreciably over the past several decades. 8 On days when youths eat fast food, compared with days when they do not, they consume more total calories, more fat, more added sugars, more sugar-sweetened drinks, and fewer fruits and vegetables. 7 , 9 Among adults, eating in fast-food restaurants is cross-sectionally associated with higher body mass index 10 and longitudinally associated with weight gain 11 , 12 and development of insulin resistance, 12 both important risk factors for diabetes. 13 Consumers’ ease of access to fast food is a priority for the industry, as business planners have long been aware of the potential to maximize sales by selecting restaurant sites that ensure close proximity to the consumer base. 14 – 16 In restaurant site selection, business planners consider neighborhood demographics and the presence of other businesses, community organizations, and aspects of the neighborhood roadways that may draw in potential consumers. 14 – 16 In recent years, public health researchers have begun to develop methods to characterize neighborhood patterns in location and density of different types of food establishments, such as fast-food restaurants or grocery stores. 17 – 20 Given the fast-food industry’s targeted marketing to children and adolescents and the importance of young people in the industry’s consumer base, we used spatial statistical methods to examine whether fast-food restaurants may concentrate in areas proximal to kindergartens and primary and secondary schools where they would be highly accessible to students.
