摘要：Objectives. We assessed the effect of the Texas Public School Nutrition Policy on middle school student lunchtime food consumption. Methods. Three years of lunch food records were collected from middle school students in southeast Texas: baseline (2001–2002), after local district changes (2002–2003), and 1 year after implementation of the Texas Public School Nutrition Policy (2005–2006). Students recorded amount and source of foods and beverages they consumed. Analysis of variance and covariance and nonparametric tests were used to compare intake after the policy change with intake during the 2 previous years. Results. After implementation of the nutrition policy, student lunch consumption of vegetables, milk, and several nutrients increased (protein, fiber, vitamins A and C, calcium, and sodium), and consumption of less desirable items (sweetened beverages, snack chips) decreased, as did percentage of energy from fat. Most of the desired nutrients and foods (vegetables and milk) were obtained from the National School Lunch Program meal. Fewer sweetened beverages, candy, chips, and dessert foods were purchased and consumed, but more of these items were brought from home and purchased from the snack bar. Conclusions. Overall, state school nutrition policies can improve the healthfulness of foods consumed by students at lunch. Public health efforts to reduce the increasing rates of childhood obesity 1 have recently focused on school food environments. 2 Although regulations exist for National School Lunch Program (NSLP) meals, there are no federal rules for competitive foods sold elsewhere in the school such as in snack bars and vending machines, except for foods of minimal nutritional value (e.g., soda). 3 This has become an issue because the school environment influences dietary behavior. 4 For example, middle school students with access to snack bar and a la carte foods consumed more sweetened beverages and french fries, and fewer fruit and vegetables compared with elementary school students without snack bars. 5 , 6 The number of snack vending machines was negatively related to daily fruit consumption among middle school youth. 7 In high schools where soft drink machines were turned off during lunch, students purchased fewer soft drinks compared with students in schools where these machines were on during lunch. 8 Improving types and portion sizes of foods available in school snack bars and a la carte could reduce the source of kilojoules available for student purchase and possibly improve energy balance. 9 States, school districts, and individual schools have enacted laws and policies regarding foods and beverages available in school food environments. 10 The beverage industry also developed a voluntary beverage vending policy for schools. 11 Such changes are controversial, and barriers to improving school food environments exist. These include the revenue generated from vending and snack bar and a la carte sales, 12 school staff, student and parent attitudes toward types of foods expected in schools, 13 and the concern that limiting access to these foods at school will not improve overall student dietary intake. 14 Critics suggest that if these items are not available in schools, students will compensate by increasing consumption of desired foods in out-of-school environments. 14 Few data exist for the effect of policy changes on actual food consumption by students at school. One recent study documented significant improvements in food consumption by Texas middle school students (more milk, calcium, and vitamin A; fewer sweetened beverages) after a local school district enacted a snack bar food policy change. 15 Consumption of chips purchased from the snack bar declined, but consumption of chips from vending machines increased, because the school administration, which was responsible for vending machines, made no changes. These results suggest that all school food sources have to make similar changes to favorably influence consumption. The Texas Public School Nutrition Policy, an unfunded mandate to promote a healthy school environment for Texas students, was implemented statewide in the fall of 2004. The guidelines apply to all school food sources, including vending machines. 16 For middle schools, the policy restricts the portion sizes of high-fat and sugar snacks (limits vary by food group), sweetened beverages (≤ 12 oz), and the fat content of all foods served (≤ 28 grams of fat per serving no more than 2 times per week). It also sets limits on the frequency of serving high-fat vegetables such as french fries (3 oz per serving no more than 3 times per week). We report the results of a naturalistic study that assessed the effect of the Texas Public School Nutrition Policy on lunch consumption of middle school students in southeast Texas. Student lunch consumption data for 2 previous years were available for comparison. 15
