J Acad Nutr Diet. 2018 May;118(5):857-864. doi: 10.1016/j.jand.2017.05.021. Epub 2017 Jul 14.
Previous studies document decreases in lunchtime milk consumption immediately after flavored milk is removed. Less is known about longer-term effects.
Plain milk selection and consumption were measured the first year flavored milk was removed in a school district (2010 to 2011 [Time 1]) and 2 years later (2012 to 2013 [Time 2]). Four behavioral economic interventions to promote milk were tested in one school at Time 2.
This was a longitudinal, observational study.
PARTICIPANTS/SETTING: Participants were kindergarten through grade 8 students in two schools in an urban district. Primary data were collected 10 times per school year at Time 1 and Time 2, yielding 40 days of data and 13,883 student observations. The milk promotion interventions were tested on 6 additional days.
Outcomes were the percentage of students selecting milk at lunch, the ounces of milk consumed per carton, and the ounces of milk consumed school-wide per student.
Logistic regressions were used to assess how sex, grade, time, availability of 100% juice, and behavioral interventions affected milk selection and consumption.
At Time One, 51.5% of students selected milk and drank 4 oz (standard deviation=3.2 oz) per carton, indicating school-wide per-student consumption of 2.1 oz (standard deviation=3.0 oz). At Time Two, 72% of students selected milk and consumed 3.4 oz per carton (standard deviation=3.2 oz), significantly increasing the school-wide per-student consumption to 2.5 oz (standard deviation=3.1 oz). Older students and boys consumed significantly more milk. Availability of 100% fruit juice was associated with a 16-percentage point decrease in milk selection. None of the behavioral economic interventions significantly influenced selection.
These data suggest that after flavored milk is removed from school cafeterias, school-wide per-student consumption of plain milk increases over time. In addition, the presence of 100% juice is associated with lower milk selection.
先前的研究表明，在去除调味牛奶后，午餐时牛奶的消耗量立即减少。但对于长期影响知之甚少。
在学区取消调味牛奶的第一年（2010 年至 2011 年[时间 1]）和两年后（2012 年至 2013 年[时间 2]），测量原味牛奶的选择和消费情况。在时间 2 时，在一所学校测试了四种促进牛奶消费的行为经济学干预措施。
这是一项纵向观察性研究。
参与者/设置：参与者为城市学区幼儿园至 8 年级的学生。主要数据在时间 1 和时间 2 时每学年收集 10 次，共 40 天的数据和 13883 名学生的观察结果。在另外 6 天测试了牛奶推广干预措施。
结果是选择在午餐时喝牛奶的学生比例、每盒牛奶的消耗量以及每位学生在校内的牛奶消耗量。
使用逻辑回归来评估性别、年级、时间、100%纯果汁的供应情况以及行为干预措施如何影响牛奶的选择和消费。
在时间 1 时，51.5%的学生选择了牛奶，每盒饮用 4 盎司（标准差=3.2 盎司），表明每位学生在校内的消耗量为 2.1 盎司（标准差=3.0 盎司）。在时间 2 时，72%的学生选择了牛奶，每盒饮用 3.4 盎司（标准差=3.2 盎司），这显著增加了每位学生在校内的消耗量至 2.5 盎司（标准差=3.1 盎司）。年龄较大的学生和男孩饮用的牛奶量明显更多。100%纯果汁的供应与牛奶选择减少 16 个百分点有关。行为经济学干预措施均未显著影响选择。
这些数据表明，在学校自助餐厅取消调味牛奶后，学生在校内饮用原味牛奶的人均消耗量会随着时间的推移而增加。此外，100%果汁的存在与牛奶选择减少有关。
