Early-life UPF intake tied to adverse behavioural outcomes in preschoolers

High consumption of ultraprocessed food (UPF) during early childhood is associated with adverse behavioural and emotional symptoms among preschool-aged children, according to a recent study.

Using data from the CHILD Cohort database, the researchers analysed 2,077 children (52.6 percent male) recruited between 2008 and 2012 across four study sites in Canada, including Vancouver, Edmonton, Manitoba, and Toronto. [JAMA Network Open 2026;doi:10.1001/jamanetworkopen.2026.0434]

Dietary intake at 3 years of age was assessed using a validated 112-item food frequency questionnaire, which categorized foods into UPF and minimally processed food (MPF) based on the NOVA classification system. UPF was further classified into eight groups: sweets and desserts, breads and cereals, animal-based products, ready-to-eat or ready-to-heat mixed dishes, artificially and sugar-sweetened beverages, sauces, spreads, and condiments, savoury snacks, and plant-based alternatives.

Behavioural and emotional outcomes at 5 years of age were evaluated through the Child Behaviour Checklist (CBCL), a standardized caregiver-reported measure assessing internalizing (eg, anxiety, fearfulness, and depression) and externalizing symptoms (eg, aggression and hyperactivity).

Results showed that UPF contributed a mean of 45.5 percent of total energy intake, whereas MPF accounted for 37.9 percent of energy intake among 3-year-old children.

UPF consumption

At the 3-year visit, the primary UPF subgroups contributing to energy were sweets and desserts (12.5 percent), breads and cereals (11.9 percent), animal-based products (7.9 percent), and ready-to-eat or ready-to-heat mixed dishes (6.1 percent).

Higher intakes of artificially and sugar-sweetened beverages were associated with higher internalizing (β=1.76) and total behaviour scores (β=1.65) but not externalizing score (β=1.22).

Additionally, higher intakes of breads and cereals and ready-to-eat or ready-to-heat mixed dishes were associated with higher internalizing scores (β=0.79 and β=1.11, respectively).

There was no strong evidence of associations among the other UPF subgroups, the researchers noted.

At the 5-year visit, higher UPF consumption was linked with increased behavioural and emotional symptoms, said the researchers.

Specifically, every 10-percent increase in energy from UPF was associated with higher CBCL scores across all domains (β=0.81 for internalizing, β=0.47 for externalizing, and β=0.64 for total behaviour score).

Dietary substitution of UPF for MPF

Substituting 10 percent of energy from UPF with MPF was associated with reduced CBCL scores, indicating improvements in behavioural symptoms across all domains (β=-0.91 for internalizing, β=-0.49 for externalizing, and β=-0.70 for total behaviour score).

“Modelling substitution of UPF for MPF was associated with lower CBCL scores, suggesting that efforts encouraging MPF in place of UPF may help to support a child’s behavioural, emotional, and mental health development,” the researchers noted.

“Overall, our findings suggest that early-life [and higher] UPF intake was associated with more behavioural and emotional symptoms at 5 years of age,” said the researchers.

“These findings reinforce existing strategies that promote minimally processed diets and highlight the importance of strengthening early-life nutrition policies to support healthy behavioural development and potentially improve later mental health,” they added.