摘要：Objectives. We examined the association between young adolescents’ dietary behaviors and school vending machines, à la carte programs, and fried potatoes’ being served at school lunch. Methods. Using a cross-sectional study design, we measured à la carte availability and the number of school stores, vending machines, and amounts of fried potatoes served to students at school lunch in 16 schools. Grade 7 students (n = 598) completed 24-hour dietary recall interviews. Results. À la carte availability was inversely associated with fruit and fruit/vegetable consumption and positively associated with total and saturated fat intake. Snack vending machines were negatively correlated with fruit consumption. Fried potatoes’ being served at school lunch was positively associated with vegetable and fruit/vegetable intake. Conclusions. School-based programs that aim to promote healthy eating among youths should target school-level environmental factors. The school environment is recognized as having a powerful influence on students’ eating behaviors. 1, 2 Ecological models of health behavior posit that such influence is multilevel and includes not only intrapersonal and social and cultural factors but physical factors as well. 3– 5 Indeed, it is the change in the physical environment of schools that has prompted many nutrition experts and public health advocates to question whether the present-day school environment supports and promotes the development of healthy eating as normative childhood behavior. 6, 7 In today’s schools, students are offered a variety of eating options and opportunities. In addition to government-regulated child nutrition programs, which include the National School Lunch and Breakfast Programs, students may purchase single food items from snack bars, à la carte programs, vending machines, and school stores; in some cases, they are allowed to leave school to buy food. Findings from the second School Nutrition Dietary Assessment study indicated that more than 90% of schools offered an à la carte program at lunchtime; 76% of high schools, 55% of middle schools, and 15% of elementary schools had vending machines available for student use; and 41% of high schools, 35% of middle schools, and 9% of elementary schools had school stores, snack bars, or canteens that sold food or drinks. 8 Overall, few of the foods offered to students via these venues are lower-fat items, fruit is rarely available, and fruit juice is a less prevalent offering than carbonated or sweetened beverages. 9– 11 Interestingly, this metamorphosis in the school environment has occurred during a time when deliberate national effort has been expended to improve the nutritional health of the US populace, particularly regarding the consumption of fruits, vegetables, and dietary fat. 12 Most children, however, do not follow the US Department of Agriculture’s (USDA’s) Dietary Guidelines for Americans, which recommend 5 or more servings of fruits and vegetables a day and limiting fat intake to no more than 30% saturated fat intake to less than 10% of daily calories consumed. 12, 13 Unhealthy dietary patterns, especially diets low in fruits and vegetables and high in fats, have been cited as the most frequently occurring chronic disease risk behavior among youths aged 12 to 17 years. 14 Clearly, focused efforts to improve the nutritional health of America’s young people are still needed, and schools, with their access to an estimated 95% of children and adolescents nationwide, 15 are regarded as optimum settings for such efforts. However, because of the many changes in the school food environment, there is a critical need to examine the association between the food options available to students at school today and the dietary practices of school-aged youths. We therefore undertook this study to assess the influence of certain school-level factors, such as the availability of vending machines and à la carte programs, on the eating behaviors of a sample of middle-school students from the upper Midwest who were participants in the Teens Eating for Energy and Nutrition at School (TEENS) study. 16 TEENS was a school-based dietary intervention trial that sought to promote healthful dietary behaviors among young adolescents to reduce future cancer risk. 16
