The five-year trial, conducted in conjunction with the Rudd Center for Food Policy and Obesity at the University of Connecticut, followed nearly 600 students from 12 schools in New Haven, Connecticut. The study is one of the first school-based policy intervention studies that followed students through middle school.
Students in schools with enhanced support to implement nutrition policies had an increase in BMI percentile of less than 1% during their four years in middle school, compared with students in schools without enhanced support for these policies and programs who demonstrated increases of 3% to 4%, according to study results.
The observed 3% to 4% difference in mean BMI percentile is equivalent to a difference of about 2 lbs. While 2 lbs may seem like negligible weight increase for a young child over four school years, researchers claimed that slowing weight gain in adolescence is clinically important to prevent adult obesity and if this trajectory is sustained over time, weight gain would substantially increase risk for severe comorbid conditions associated with overweight and obesity, such as metabolic and cardiovascular risks, as well as musculoskeletal disorders, depression, and more.
"These findings strongly support previous administration policies that provided healthier food for all children in public schools," noted lead author Jeannette Ickovics, professor of social and behavioral sciences at the Yale School of Public Health.
Last week, the Trump Administration announced a final rule on child nutrition programs – affecting nearly 99,000 schools and 30 million children – that offered more flexibility on the amount of whole grains, milk options, and sodium content in school meals. The rule was met with criticism from health advocacy groups including the Oldways Whole Grains Council and CSPI who all argued that the changes unnecessarily reversed the nutritional progress schools had made in getting kids to eat healthier.
Other groups such as the School Nutrition Association supported the rule, stating it strikes a healthy balance and will "entice more students to eat healthy school meals."
"This is some of the strongest evidence we have to date that nutrition education and promoting healthy eating behaviors in the classroom and cafeteria can have a meaningful impact on children's health," said Marlene Schwartz, director of the Rudd Center and senior study author.
"These findings can inform how we approach federal wellness policy requirements and implementation in schools to help mitigate childhood obesity."
Thorough implementation of advanced nutrition policies lead to healthier eating habits
The racial diversity of the group of students included in the study was 47.2% Hispanic, 35.0% black, and 17.8% white/other with a mean age of 10.9 (fifth grade) who completed baseline surveys as well as height and weight measurements by trained health professionals to determine BMI.
Researchers collected the same information one more when the students were in the eighth grade (2014-2015 academic year).
Each school received a $500 stipend at the beginning of the study to create a ‘School Wellness Team’ and was assigned one research staff member who visited the school one to two times per month. Visits typically included meeting with the School Wellness Team, principal, all teachers for the target grade, school cafeteria manager, and physical education teachers. Newsletters were distributed three timers per year to reinforce targeted health messages (e.g., ‘Rethink Your Drink’ campaign).
Advanced nutrition interventions included cafeteria-based nutrition promotion to encourage healthy food choices, taste-testing new foods, and providing alternatives of sugary and unhealthy foods typically served during school celebrations.
According to the study, students who attended schools that were randomized to receive support to implement nutrition-focused school wellness policies were significantly less likely to experience an increase in BMI across middle school (from fifth through eighth grade) than students in comparison schools.
At the end of the study, these students reported lower consumption of unhealthy foods and sugar-sweetened beverages, although there was no effect on consumption of healthy foods and beverages.
"These findings can guide future school and community interventions. Childhood obesity is a serious health threat, and schools are a vital way to reach children and their families to reduce risks and promote health," said Ickovics.