When it comes to healthy eating for kids, public health experts often look to schools for answers because children spend much of their time and consume much of their calories there. And thanks to national childhood obesity initiatives over the past several years, salad bars are showing up in schools across the country. But do they work?
In New Orleans, the national Let's Move! Salad Bars to Schools initiative donated salad bar structures to 43 local schools starting in 2011. With so many schools poised to see a shift in their cafeterias, the Tulane Prevention Research Center (PRC) began its School Salad Bar Evaluation Study in 2013 and recently published two papers with results from the research. These papers build on the PRC's previously published school salad bar research.
The first paper, published online in the scientific journal Health Education & Behavior in February 2017, found that students at secondary schools with high levels of marketing for the salad bar were nearly three times as likely to use the salad bar compared to students at secondary schools with low levels of salad bar marketing. Among students in both elementary and secondary schools, females used salad bars more often than male students, and children who preferred healthy foods also used them more frequently. The findings were based on surveys with students, administrators and food service staff at 12 public schools. Tulane PRC student research assistants also tracked the schools' environment and marketing practices through in-person visits. Examples of salad bar marketing efforts included signs posted throughout the school to promote the salad bar, notes to parents about the salad bar, and taste-testings of salad bar items.
"The value of a salad bar program depends on whether students actually use the salad bar, but few studies have examined how to make that happen more effectively," said Lori Andersen Spruance, an Assistant Professor of Health Science at Brigham Young University in Utah, who managed the study while a doctoral student and research coordinator at the Tulane PRC.
A second paper on the salad bar study was published online in the International Journal of Environmental Research and Public Health in April 2017. This paper explored the sources of fruit and vegetables students consumed via a 24-hour dietary recall, an interview-assisted web-based platform to report detailed information on all food and drink consumed within the previous 24-hour period.
More than 700 students, at schools with and without salad bars, completed the dietary recalls. Researchers found that overall, most students at some amount of fruit and vegetables at lunch. And among those students, most of their fruit and vegetables were from the schools' cafeteria main food line. In schools with salad bars, the students who used the salad bar ate more fruits and vegetables overall than their counterparts who did not use the salad bar. The study also found that 15 percent of students who participated in the study reported they did not eat lunch in the past 24 hours.
"Since students were getting most of their fruit and veggies from the main food line, they were not using the salad bar along for lunch. Other factors, such as the variety and quality of the produce, as well as attractive displays and promotional signs, can influence use and these were not examined in this study," said Carolyn Johnson, Director of the Tulane PRC, study author, and Professor in the Department of Global Community Health and Behavioral Sciences at the Tulane University School of Public Health and Tropical Medicine. "Furthermore, we are concerned that some youth are not eating lunch at all, and therefore potentially missing essential nutrients. Schools need to be aware of this so they can address it."