Children’s food choices and eating habits are impacted by a variety of individual and environmental factors (1
). The school environment is one important influence that plays a significant role in teaching and modeling eating behaviors to children (2
). With demonstrated inadequacies in children’s diets (3
) and the rising rates of overweight children in the US (6
), the school food environment is a potentially modifiable factor that has received attention in recent years (7
Students have a wide variety of eating options and opportunities in schools, and foods and beverages consumed during the school day provide a significant portion of children’s daily nutrient intake (2
). The three main sources of foods and beverages consumed in schools are federally reimbursable USDA school nutrition programs (the National School Lunch Program [NSLP] and the School Breakfast Program [SBP]); food and beverages sold in a la carte lines, snack bars, school stores, vending machines or school activities (e.g., fundraisers, classroom parties); and foods brought from home (7
). Foods and beverages sold in schools outside of the NSLP or SBP are referred to as “competitive foods”. In contrast to NSLP or SBP meals, competitive foods are not required to follow any federal nutrition guidelines and are frequently Foods of Minimal Nutritional Value (FMNV), defined as “those that provide low amounts per portion of specified nutrients (e. g., soft drinks, candy, chips)” (8
). Competitive foods are widely available in middle and high schools in the US, and vending machines are the most common provider of these foods with 82% of middle schools and 97% of high schools having vending machines (9
). There have been recent measures to try to improve the school food environment. In the Child Nutrition and WIC Reauthorization Act of 2004 (Public Law 108-265), the US Congress established a new requirement that all school districts with a federally-funded school meals program develop and implement wellness policies that address nutrition and physical activity by the start of the 2006-2007 school year. However, it is left to the schools to determine specifically what will be addressed in their wellness policies and how they will implement the policies.
Although it is well-documented that the majority of US schools sell FMNV (9
), few studies have examined the association between foods sold in schools and student outcomes. In the Teens Eating for Energy and Nutrition at School (TEENS) study of Minnesota middle school students, a la carte food availability was negatively associated with fruit and fruit/vegetable consumption and positively associated with total and saturated fat intake (10
). In addition, having vending machines in schools was negatively associated with fruit consumption. Another study of 8th
graders (n=3,088) from the TEENS study examined the relationship between body mass index (BMI) and school-wide food practices (e.g., allowing snacks in the hallways, using food as incentives) (11
). For every additional unhealthy food practice that was permitted in the school, BMI of the students increased by 10%. Recently, a study of 9,151 students from 64 middle schools in WA found that sugar sweetened beverage exposure (SSB) at school significantly predicted total SSB consumption (β=0.157, p<0.001) (12
). Although these studies provide important data they were each conducted in a single geographic location and included children in a limited age range. More recent data on the availability and consumption of competitive foods in 287 US public schools (grades 1 through 12) from the 3rd
School Nutrition Dietary Assessment Study (SNDA-III) (13
) indicated that competitive foods were available in 73% of elementary schools, 97% of middle schools and 100% of high schools. In addition, 40% of children consumed one or more competitive foods daily and consumption was highest in high school students. Although the SNDA-III provides important descriptive national data on the school food environment, to date, no national study has examined the relationship of competitive foods available in schools to school-level variation in students’ overall dietary intake.
The aim of the current study was to examine the association between foods sold in school vending machines and students’ dietary intake. Data were collected as part of the 2005-2006 US Health Behavior in School-aged Children survey. It was hypothesized that foods and beverages available in school vending machines would positively relate to the corresponding food intake in students.