Students in the U.S. consume nearly half of their calories from school meals, providing an opportune setting for improving their diets. Schools across the nation have been removing chocolate milk from their meal programs in an effort to reduce students' intake of added sugar. Some people have expressed concerned that the new policy would lead to a decrease in students' milk consumption and, specifically, reduce the essential nutrients milk provides, such as calcium, protein and vitamin D. They also fear that the policy could lead to an increase in milk waste.
Two past studies, one in Oregon and one in Massachusetts, found that total milk sales decreased or milk waste increased after schools implemented a policy to remove chocolate milk. However, results from a new study by the University of California Nutrition Policy Institute (NPI) revealed that while removing chocolate milk modestly reduced students' milk consumption, it did not compromise average intake of key milk-related nutrients.
Researchers collected data on milk selection and consumption during one lunch period in 24 California public secondary schools pre-policy (3,158 students in 2016) and post-policy (2,966 students in 2018). The student population was 38% Asian and 29% Latino, with 63% qualifying for free or reduced-price meals. The researchers used linear mixed effects models to assess changes in milk selection and waste. They also estimated related changes in added sugars, calcium, protein and vitamin D consumed from milk.
According to the researchers, this was the first study to examine the effect of a district-level chocolate milk removal policy on milk selection and consumption among racially/ethnically and socioeconomically diverse middle and high school students.
The research found that the proportion of students selecting milk declined 13.6%, from 89.5% pre-policy to 75.9% post-policy, but the proportion of milk wasted remained stable, at 37.1% versus 39.3%. Although average milk consumption declined by less than 1 oz. per student, researchers observed no significant reductions in average intake per student of calcium, protein or vitamin D from milk. Meanwhile, estimated added sugars from milk declined significantly, by 3.1 g per student, the study found.
The researchers said their results suggest that a school policy to remove chocolate milk may reduce middle and high school students' added sugar intake without compromising their intake of essential nutrients or increasing milk waste.
As such, they recommended that secondary schools consider removing chocolate milk to support healthy beverage consumption.
The study was conducted by NPI affiliated researchers Hannah Thompson and Esther Park from the University of California Berkeley School of Public Health, in collaboration with NPI researchers Lorrene Ritchie and Wendi Gosliner and Kristine Madsen from the Berkeley Food Institute and School of Public Health. The study was published online Aug. 27, 2020, in the journal Preventing Chronic Disease.