Chef-enhanced school meals increase the consumption of fruits and vegetables by students, according to a recent study from Harvard University.

More than 30 million students get school meals daily and many of them rely on school foods for up to half of their daily calories. Therefore, school-based interventions that encourage the selection and consumption of healthier foods, such as fruits and vegetables, can have important health implications, according to the study background.

For the study, researchers conducted a randomized clinical trial to examine the effects of short-term and long-term exposure to meals made more palatable with the help of a professional chef who taught school staff culinary skills and extended daily exposure to "choice architecture" in a smart café intervention where fruits were placed in attractive containers, vegetables were offered at the front of the lunch line and white milk was placed in front of sugar-sweetened chocolate milk.

They collected and analyzed data from 14 elementary and middle schools in two urban, low-income school districts, including 2,638 students in grades 3 through 8. Intervention schools received a professional chef who collaborated with them and then students were repeatedly exposed to new recipes on a weekly basis during a seven-month period. The modifications made to school cafeterias as part of the smart café intervention were applied daily for four months.

They found that after three months of chef-enhanced meals, entree and fruit selection were unchanged but the odds of vegetable selection increased compared with control schools. After seven months, entree selection remained unchanged in the intervention schools compared with control schools. However, the odds of students selecting fruit increased in the chef, smart café and chef plus smart café schools compared with controls. Among the students who selected fruit, the servings consumed were greater in chef schools compared with control schools but there was no effect of the smart café intervention.

The odds of students selecting vegetables also increased in the chef, smart café and chef plus smart café schools compared with control schools. The percentage of vegetables consumed increased by 30.8 percent in chef schools and by 24.5 percent in chef plus smart café schools compared with control schools, according to the study. Selecting a meal component and consuming a meal component were measured separately.

There were no changes in the selection or consumption of white or sugar-sweetened chocolate milk in the smart café schools where students had access to both, the results indicate.

"Efforts to improve the taste of school foods through chef-enhanced meals should remain a priority because this was the only method that increased consumption. This was observed only after students were repeatedly exposed to the new foods for seven months. Therefore, schools should not abandon healthier options if they are initially met with resistance," the study concludes.

The findings are detailed in JAMA Pediatrics.