Toddlers Eating More Ultra-Processed Foods Show Increased Behavioral Symptoms: Study

A recent study published in JAMA Network Open suggests that diets high in ultra-processed foods (UPFs) during early childhood may be linked to later behavioral challenges.

Researchers analyzed data from 2,077 Canadian children and found that greater consumption of UPFs at age three was associated with slightly higher caregiver-reported behavioral and emotional symptom scores by age five.

Although the effects were modest, the findings highlight how early dietary patterns may influence children’s developmental outcomes.

Early childhood is a crucial stage for emotional and behavioral development. During this period, children may display internalizing behaviors such as anxiety or withdrawal, as well as externalizing behaviors like aggression and hyperactivity. These patterns can sometimes signal later mental health difficulties.

Diet is considered a potentially modifiable factor influencing these outcomes, yet most previous studies have focused on specific nutrients rather than overall eating patterns.

The researchers used data from the CHILD Cohort Study, a large multi-center study conducted across Vancouver, Manitoba, Toronto, and Edmonton. Dietary intake at age three was measured using a 112-item food frequency questionnaire, with foods classified according to the NOVA food classification system. Behavioral outcomes at age five were evaluated using the Child Behavior Checklist based on caregiver responses.

Results showed that UPFs contributed about 46% of total daily calorie intake among the children studied. Each 10% increase in calories from UPFs was linked to small increases in behavioral symptom scores. In contrast, statistical substitution models indicated that replacing 10% of calories from UPFs with minimally processed foods was associated with modestly lower behavioral symptom scores.

Overall, the study suggests that healthier, minimally processed diets in early childhood may support better behavioral development, reinforcing the importance of nutrition guidance and policies that promote whole-food eating patterns for young children.

REFERENCE: Kavanagh, M.E., Chen, Z.H., Tamana, S.K., et al. (2026). Ultraprocessed Food Consumption and Behavioral Outcomes in Canadian Children. JAMA Network Open;9(3):e260434. DOI:10.1001/jamanetworkopen.2026.0434, https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2845768