Lunch and recess provide a nice break for students in the middle of the day. But it can make a difference when they are scheduled. The idea is to find times when kids both eat best and get the most exercise. Does it matter whether lunch comes first and recess second, or vice versa?

Researchers looked at how much food middle school students ate relative to physical activity at recess, tracking how long kids spent at each, depending on whether lunch, or recess, came first in students' schedules.

Currently, the CDC recommends that recess be offered before lunch in order to reduce food waste. But putting recess before lunch also has some undesirable effects.

Two groups of fourth and fifth grade students from two different public schools took part in the study. One school had lunch before recess, the other recess before lunch. Both schools were in low income neighborhoods. The University of Illinois, Urbana-Champaign researchers measured how much food was thrown away in each school, how many vegetables were consumed and how much the kids exercised at recess.

They found that when recess was before lunch, the kids wasted less food overall. But when lunch was before recess, they ate more vegetables.

The amount of time kids had for recess and lunch also mattered. When time was tight, kids were more active when recess came before lunch. When they had more time for recess and lunch, they were more active when lunch came before recess.

“Overall, our findings suggest that recess and lunch behaviors are interrelated,” said author and doctoral candidate, Gabriella McLoughlin, in a statement.

Currently, the CDC recommends that recess be offered before lunch in order to reduce food waste. This is certainly a legitimate recommendation, since some kids may not have enough nutritious food outside of school, and ever-decreasing school budgets make reducing food waste desirable. But it’s more complicated than this, the study suggests. Putting recess before lunch may also bring some undesirable effects — it can reduce the amount of exercise kids get depending on how long the period is, and can affect the kinds of food choices kids make. And then there is the fact that nutrition suffers during short lunches.

The team plans to expand on their findings, hopefully providing more information, so that schools and policymakers can make decisions about scheduling that best support students’ well being. Parents concerned about the amount of time their middle schoolers have for lunch and recess may want to contact their school's administration.

The study was presented at the annual Experimental Biology 2017 meeting in Chicago this month.