What kids eat at school may matter more than we think, TMU research suggests
Making sure kids have enough to eat during the school day has long been known as a key ingredient in their ability to learn — but new research suggests that what they eat may be just as important.
A study (external link) led by Nick Bellissimo, professor and director of TMU’s Nutrition Discovery Labs in the School of Nutrition, found that children who had milk or yogurt as a mid-morning snack performed better on certain memory tasks than those who had cheese, a sugary drink or no snack at all.
“Most previous studies compared calories versus no calories,” said Bellissimo. “What we’re showing is that not all foods are equal. What you eat matters.”
How the study worked
The study, published in Applied Physiology, Nutrition, and Metabolism, took place at TMU between December 2022 and October 2023.
It involved 54 children aged nine to 14, an age when eating habits are becoming more independent and cognitive demands are increasing.
Each child visited the lab multiple times. The setup was designed to mirror a typical school-day schedule: kids had breakfast, then two hours later, ate a mid-morning snack timed to replicate a recess break. On different visits, they were given milk, yogurt, cheese, a sugar-sweetened beverage or no snack at all.
Researchers then measured their cognitive performance over two hours using standardized memory tests across five areas: short-term memory, spatial working memory, sustained attention, selective attention and executive functioning.
Nick Bellissimo
Where milk stood out
Of the five areas tested, spatial working memory showed the clearest response to snack type. Spatial working memory is the brain's ability to temporarily hold and use visual information — like remembering a sequence or a location.
Children who drank milk performed best overall, particularly when asked to recall sequences in the order in which they were given.
“In the forward condition (when kids were asked to recall the same items in the original order), milk performed better than all other forms of dairy… compared to cheese, yogurt, the sugar-sweetened beverage and also having no snack at all,” said the study’s first author, Megan Wurtele, who was in TMU’s Bachelor of Applied Science in Nutrition and Food program at the time of the study, and who recently completed TMU’s Master of Health Science in Nutrition Communication program.
Yogurt also showed benefits, particularly compared to no snack.
“In the backward condition (when kids were asked to recite the pattern they had been given in reverse order), both milk and yogurt performed better than having no snack at all,” she explained.
Wurtele says the results highlight how everyday food choices can have immediate effects.
“We found that milk and yogurt improved acute cognitive performance in children, specifically in the domains of spatial working memory,” she said.
Moving beyond ‘just eat something’
For years, much of the research in this area focused on whether kids ate breakfast at all, rather than what they ate.
Previous studies also looked at foods in combination, such as milk with cereal, making it difficult to pinpoint which ingredient was driving any cognitive benefits.
This study took a different approach: isolating dairy products and comparing different forms of them directly. That design allowed researchers to draw clearer conclusions about what might actually be happening in the brain.
What this means for parents and schools
Researchers say the effects were modest and short-term, but measurable, with early signs of differences between boys and girls (which requires further study).
While it’s too soon to link the findings to academic outcomes, the research opens the door to exploring how diet may support children’s cognitive development.
The team is now looking to explore how other dairy products, including chocolate milk and other flavoured milk, as well as plant-based dairy alternatives like almond milk, may influence digestion and brain function.
The study was conducted by researchers at TMU’s School of Nutrition, involving undergraduate trainees and research assistants, reflecting the program’s emphasis on experiential learning and real-world research training.
This research was funded by the U.S. National Dairy Council.
Media interviews
Media interested in interviewing professor Nick Bellissimo about this study can contact him at nick.bellissimo@torontomu.ca.
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