A new study says there appears to be a link between consumption of ultra-processed foods (UPF) in preschool years and behavioural issues in childhood.
Nearly 3,500 families contributed to the cohort, which followed the children from before birth to adolescence in Vancouver, Edmonton, Winnipeg and Toronto. The researchers then assessed the children’s emotional and behavioural well-being two years later, when they were five.
It was found that “higher UPF intake at age three years was associated with adverse behavioural and emotional symptoms at age five years.”
In addition, for every 10 per cent rise in calories coming from ultra-processed foods, five-year-olds had higher instances of “internalizing” behaviours (44.6 per cent), such as anxiety and fearfulness, and “externalizing” behaviours (39.6 per cent), including aggression and hyperactivity, as well as overall behavioural difficulties.
Almost half (48 per cent) of Canadian preschoolers’ daily energy intake came from ultra-processed foods, yet the researchers note that little is understood about how UPFs might influence their behavioural and emotional development.
Kozeta Miliku, the clinical science officer of the CHILD cohort study, found the results to be “really alarming.”
“When you see the food environment around us, it’s something that we expect. And in this study, we did examine whether this ultra-processed food intake in their child[‘s] food, so among three-year-olds, is linked to the behaviour and emotional development,” she said.
The study found that the main ultra-processed food subgroups contributing to energy were sweets and desserts (12.5 per cent), breads and cereals (11.9 per cent), animal-based products (7.9 per cent) and ready-to-eat or ready-to-heat mixed dishes (6.1 per cent).
The ultra-processed food subgroup for children at age found that “higher intake of artificially and sugar-sweetened beverages was associated with a higher internalizing score and total behaviour score but not externalizing.”
It was also uncovered that the three-year-olds surveyed had “higher intakes of breads and cereals and ready-to-eat or ready-to-heat mixed dishes were associated with higher internalizing scores.”
Get weekly health news
Receive the latest medical news and health information delivered to you every Sunday.
One of the indicators that Miliku pointed out for kids consuming more ultra-processed foods is “not only the family cell” but “also the environment level.”
“The longer the commute, the higher the chance for their children to be fed more ultra-processed food, or the accessibility to a fresh fruit and veggie market to lower the ultra-processed food consumption,” she said. “It was really interesting to see that it’s not just families, it’s not just the parents themselves, but it’s more the environment around us that pushes towards this ultra-processed food consumption.”
Theo Moraes, the Toronto site director for the CHILD Cohort study and head of respiratory medicine at SickKids Toronto, said that all of these factors can be “intertwined.”
Moraes said that “when you look at children’s diets in early life, there are associations with behaviour in older life.”
“There’s a lot of things we know are healthy for us. Diet is one of them. Getting enough sleep, getting enough exercise, but actually implementing it in our lives can be tough.”
Miliku also noted that implementing healthy eating habits early and consistently can have a positive impact on a child’s mental health.
“Early childhood is really a sensitive period for brain development. So, during this stage, children are establishing both dietary habits and behavioural patterns,” she said.
“When we think about the long-term, research has shown that behaviour patterns in early childhood can track into later childhood and adolescence, and they may be associated with later mental health outcomes.”
Healthy eating is not about blame
Miliku emphasized that these findings are meant to “really think in a holistic approach rather than just making parents feel guilty.”
“It’s such a strong, important message because we as parents feel the blame. But seeing that it’s not just the family level, but it’s more from the family to the society or urban development, it’s really important to also talk about those issues as well,” she said.
This is a sentiment that Moraes also echoed.
“I think there’s a lot of pressure on parents. We don’t want our data, our research, our findings to create a lot of guilt for parents as well. And so that’s also something to be careful of,” he said.
© 2026 Global News, a division of Corus Entertainment Inc.
