BACKGROUND The Healthy, Hunger-Free Kids Act (HHFKA) 2010 updated standards to increase the nutritional quality of school meals. Studies of HHFKA outcomes have focused primarily on fruit and vegetables, nutrient quality of whole meals, and plate waste. OBJECTIVE To examine changes in school lunch entrée nutrient quality and student selections after HHFKA implementation. DESIGN Descriptive, longitudinal study analyzing 1.7 million student-selected lunch entrées in eight entrée categories. PARTICIPANTS/SETTING Three middle schools and three high schools in an urban school district in Washington State, from January 2011 to January 2014 (16 months before and 15 months after HHFKA implementation). MAIN OUTCOME MEASURES Nutritional quality of each entrée category was assessed by analyzing mean adequacy ratio, energy density, and energy per serving. Selection was determined by analyzing number of entrées in each category selected by students. STATISTICAL ANALYSES PERFORMED Comparison of indices of pre- and postimplementation nutritional quality using a combination of Wilcoxon two-sample test with t approximation and a two-sided alternative t test assuming equal variances and t test assuming unequal variances using Satterthwaite approximation. Quantity of entrée categories selected was also determined by Satterthwaite approximation. RESULTS After implementation, there was significant improvement in mean adequacy ratio and energy per serving overall for all entrées combined. There were significant improvements in both mean adequacy ratio and energy per serving for salads, burritos, and pizza in middle schools and for hot sandwiches and burritos in high schools. For energy density, middle schools also had significant decreases for casseroles and salads, with no significant changes found in high schools. The variety of entrées decreased by 44%, and there were significant changes in the proportions of entrées selected from specific food categories. CONCLUSION Nutritional quality of lunch entrées, variety of entrées available, and student entrée selections changed after implementation of HHFKA policy in one urban school district in Washington State.

中文翻译：

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2010 年《健康、无饥饿儿童法案》实施前后的学校午餐主菜

背景 健康、无饥饿儿童法案 (HHFKA) 2010 更新了标准以提高学校膳食的营养质量。HHFKA 结果的研究主要集中在水果和蔬菜、全餐的营养质量和餐盘浪费上。目的 检验 HHFKA 实施后学校午餐主菜营养质量和学生选择的变化。设计 描述性的纵向研究分析了 170 万学生选择的八个主菜类别的午餐主菜。参与者/地点 2011 年 1 月至 2014 年 1 月（HHFKA 实施前 16 个月和实施后 15 个月）华盛顿州城市学区的三所中学和三所高中。主要结果测量通过分析平均充足率、能量密度和每份能量来评估每个主菜类别的营养质量。通过分析学生选择的每个类别中的主菜数量来确定选择。执行的统计分析 使用具有 t 近似值的 Wilcoxon 双样本检验和假设方差相等的双侧替代 t 检验和使用 Satterthwaite 近似值假设不等方差的 t 检验相结合，对实施前和实施后的营养质量指数进行比较。所选主菜类别的数量也由 Satterthwaite 近似确定。结果 实施后，所有主菜的平均充足率和每份能量都有显着改善。中学的沙拉、墨西哥卷饼和比萨饼以及高中的热三明治和墨西哥卷饼的平均充足率和每份能量都有显着改善。对于能量密度，中学的砂锅菜和沙拉也显着减少，高中没有显着变化。主菜的种类减少了 44%，从特定食物类别中选择的主菜比例发生了显着变化。结论 在华盛顿州的一个城市学区实施 HHFKA 政策后，午餐主菜的营养质量、可用主菜的种类和学生主菜的选择发生了变化。