Could postponing lunch for play help curb childhood obesity?

Flipping the order of kids’ meals and activities at their school lunch break is enough to make some forego junk food and eat less, a new Montreal study has found.

Montreal study finds post-exercise period ideal time to eat

Researchers found, like young adults, kindergarten students were satiated and ate less when they had their meals immediately after vigorous exercise. (Shutterstock)

Flipping the order of kids' meal and play at their school lunch break is enough to make some forego junk food and eat less, a new study by Montreal researchers has found.

The study, recently published in the journal Appetite, found that children in kindergarten who participated in vigorous exercise before they were given their lunch boxes chose healthy options over sweets and ate less, when compared to children who ate their meals before playing or had some downtime before their meal.   

The science behind the study centres on the appetite-stimulating hormone ghrelin, which drops during exercise. The research team found university students in the lab felt full after eating less in the post-exercise period, when their appetite levels were lower.

The researchers wanted to see if that finding would be replicated in children who were less conscious of their food choices

"Five-year-olds don't really think about the fact that, 'I exercised, so I will eat better after,' so it's really working," said Université de Montréal Prof. Marie-Eve Mathieu, who co-authored the study.

The kinesiologist said she and her fellow researchers also looked further into dinner-time eating and found eating less at lunch didn't impact the amount eaten later in the day.

Researchers gave children a lunch box that included both healthy and sugary options, and found after active play, the five-year-olds chose healthy food over sweets. (Liz Kloepper)

Active play is key

Simply switching the order of lunch and leisure isn't enough to change eating habits, the study stressed. The play portion of the break needs to involve moderate to vigorous activity in order for the positive effects to be felt.

The researchers did not alter the time allotted for the students' lunch break but did prepare their lunch boxes with a mix of healthy options and a few sweet treats.

The study, funded in part by the Sainte-Justine University Hospital Centre, took place over a three-week period and involved 21 children.

"One goal of the study is [for it] to be easily replicated in other schools," Mathieu said. "Schools can decide just to switch their activity at lunchtime when it's possible."

Mathieu said the next step will be to study the long-term effect of delaying the midday meal.

With files from CBC Montreal's Daybreak


To encourage thoughtful and respectful conversations, first and last names will appear with each submission to CBC/Radio-Canada's online communities (except in children and youth-oriented communities). Pseudonyms will no longer be permitted.

By submitting a comment, you accept that CBC has the right to reproduce and publish that comment in whole or in part, in any manner CBC chooses. Please note that CBC does not endorse the opinions expressed in comments. Comments on this story are moderated according to our Submission Guidelines. Comments are welcome while open. We reserve the right to close comments at any time.