Researchers from Brigham Young University (BYU) and Cornell University conducted a study among one to sixth graders in Orem, Utah, near Salt Lake City.
The school district was in the process of switching the lunch/recess order in some schools, and the researchers realized that the switch presented an opportunity to see if it made a difference in children's fruit and vegetable consumption habits.
Seven schools within the district participated in the study, three of which switched recess to before lunch and four continued to hold recess after lunch.
After analysing a total of 22,939 observations, the researchers concluded that in the schools that switched recess to before lunch, children ate 54 percent more fruits and vegetables.
There was also a 45 percent increase in those eating at least one serving of fruits and vegetables.
Many schools in the US have reported that fruits and vegetables are feeding trash cans rather than students.
The researchers measured fruit and vegetable waste by standing next to the trash cans and recording the number of servings of fruits and vegetables that each student consumed or threw away.
David Just from Cornell University said, "Recess is often held after lunch so children hurry to 'finish' so that they can go play. This results in wasted fruits and vegetables. We found that if recess is held before lunch, students come to lunch with healthy appetites and less urgency and are more likely to finish their fruits and vegetables."