A Canadian study examined the link between ultra-processed food consumption in three-year-olds and their behaviour at age five, revealing its impact.
A study conducted in Canada by a team of researchers at the University of Toronto investigated the association between the consumption of ultra-processed foods and behavioural and emotional functioning in children. The results, published in JAMA Network Open, suggest that higher consumption of ultra-processed foods in early childhood (age three) is associated with behavioural and emotional difficulties, including anxiety, fearfulness, aggression and hyperactivity, at age five. Conversely, replacing a portion of ultra-processed foods with minimally processed foods was found to be associated with better behavioural and emotional outcomes.
The researchers analysed dietary data from 2,077 Canadian children aged three. Two years later, when the children were five, the team assessed preschoolers' scores using the Child Behavior Checklist, a validated tool that measures emotional and behavioural wellbeing in young children, where higher scores indicate greater reported behavioural difficulties.
For every 10 per cent increase in energy from ultra-processed foods, children showed higher scores on tests relating to internalising behaviours such as anxiety and fearfulness, and externalising behaviours such as aggression and hyperactivity, as well as general behavioural difficulties. Certain categories of ultra-processed foods showed stronger associations, particularly sugar-sweetened beverages and artificially sweetened drinks. Ready-to-heat meals, such as French fries or macaroni and cheese, were also associated with higher scores.
In statistical models simulating dietary changes, replacing 10 per cent of energy from ultra-processed foods with minimally processed foods such as fruit, vegetables and other whole foods was associated with lower behavioural scores.
"Our findings suggest that, in early childhood, even modest shifts towards minimally processed foods — such as adding a piece of fruit or replacing a sugary drink with water — can support healthier behavioural and emotional development, with potential long-term mental health benefits," said Kozeta Miliku, lead author of the study.
The scientists also highlight the need to consider parental guidance, public health campaigns and the reformulation of certain packaged foods.