Socioeconomic and Demographic Determinants of the Nutritional Content of National School Lunch Program Entrée Selections
研究利用混合逻辑模型分析美国学校午餐计划中学生的主菜选择，发现免费午餐学生更倾向高脂低钠食品，而全价午餐学生对营养变化最敏感，替换不健康菜品可减少约4%总热量、18%脂肪热量和8%钠摄入。
New National School Lunch Program (NSLP) guidelines aim to reduce sodium and saturated fats, limit calories, and eliminate trans‐fat and whole milk. This paper provides a novel approach to understanding how the healthfulness of NSLP participants’ entrée selections varies across socioeconomic and demographic groups. Unlike previous studies that rely on dietary recalls, we use a mixed logit model to examine students’ entrée choices in a school cafeteria. We estimate the likelihood that an entrée is selected from the available lunch choices as a function of the entrée's nutrients (fat, carbohydrate, protein, and sodium) and entrée's taste profile characteristics (e.g., Mexican, Pizza‐like), as well as the student's socio‐economic and demographic characteristics. Using these estimates, we examine how changing the nutritional content of an offering impacts the probability of selecting each of the offerings. Free lunch recipients are more likely to choose entrées higher in fat but lower in sodium than other students. Full‐price lunch recipients are the most responsive to changes in nutritional content of the offerings and are most likely to respond to changes in the nutritional content of the offered entrées by substituting a lunch brought from home for the school‐purchased lunch. Replacing less healthy menu items with popular but healthier items reduces the selection of total calories, calories from fat, and sodium by approximately 4%, 18%, and 8%, respectively, over the study period. The new guidelines should be effective at improving the nutrition of school‐age children, and potentially reducing childhood obesity, provided NSLP participation does not decline appreciably.