Breaking News:Study finds toddlers who eat more ultra-processed foods show slightly higher behavioral symptoms– What Just Happened

A large Canadian cohort study suggests that preschool diets high in ultra-processed foods may be associated with slightly higher behavioral symptom scores in early childhood, while modest shifts toward minimally processed foods could be linked to improved behavioral outcomes.

Study: Ultraprocessed Food Consumption and Behavioral Outcomes in Canadian Children. Image Credit: IMG Stock Studio / Shutterstock

A recent study published in JAMA Network Open suggests that diets high in ultra-processed foods (UPFs) in early childhood may be linked to later behavioral challenges. Analyzing data from 2,077 Canadian children, researchers found that increased UPF intake among three-year-olds was associated with slightly higher caregiver-reported behavioral and emotional symptom scores by age five. In substitution models, replacing 10% of calorie intake from UPFs with unprocessed or minimally processed foods (MPFs) was associated with modestly lower behavioral symptom scores. Although the effects were modest, the findings highlight that early dietary patterns may influence child development, reinforcing the importance of policies promoting healthier, minimally processed diets.

Early Childhood Development and Behavioral Health

Early childhood is a critical period for emotional and behavioral development, with lasting effects on psychosocial well-being and health. During this time, children may show internalizing symptoms such as anxiety and withdrawal or externalizing behaviors like aggression and hyperactivity, patterns that can signal later mental health challenges. At the same time, mental health disorders among children appear to be increasing.

Diet is a potentially modifiable factor influencing behavioral development. However, most research has focused on individual nutrients rather than overall dietary patterns. Notably, UPFs account for almost half of daily calorie intake among preschoolers in Canada, raising questions regarding their influence on early developmental outcomes.

Study Design and Cohort Data

In the present study, researchers investigated the relationship between UPF consumption and early behavioral development.

The team analyzed data from the CHILD Cohort Study, a prospective, multi-center pregnancy cohort conducted across Canadian sites in Vancouver, Manitoba, Toronto, and Edmonton. The data included behavioral and dietary information from 2,077 preschool-aged children obtained between September 2011 and April 2018. None of the participants had congenital abnormalities. The researchers also reported that children included in the final analyses were more likely to have mothers with higher education and household income than those excluded from the analytic sample.

The researchers analyzed data between February and July 2025. They used a food frequency questionnaire (FFQ) comprising 112 items to assess dietary intake at three years of age, categorizing foods according to the NOVA classification system. They evaluated behavioral and emotional outcomes at five years using the Child Behavior Checklist (CBCL) T-score scales based on caregiver responses, which represent standardized behavioral and emotional symptom scores rather than clinical diagnoses.

Statistical Analysis and Adjusted Factors

The team performed linear regression modeling to examine the association between UPF intake and behavioral outcomes, expressing UPF as a percentage of total calorie intake. They adjusted for several potential confounders, including maternal, child-related, and sociodemographic factors.

Maternal factors included education, marital status, prenatal stress measured by the Perceived Stress Scale (PSS), and maternal UPF intake during pregnancy. Child-related factors included sex, ethnicity, gestational age at birth, and exclusive breastfeeding at six months. Additional adjustments included calorie intake and childcare exposure at age 3. The team also adjusted for physical activity and body mass index (BMI) at age five based on the World Health Organization (WHO) criteria. Sociodemographic factors included household income, older siblings, study site, and season.

Further, the researchers modeled the effects of replacing 10% of UPF intake with MPF. They also conducted sensitivity analyses accounting for nutrients of concern associated with UPFs (sodium, saturated fat, and total sugar), changes in UPF consumption between ages three and five, and screen time at age five.

Results: UPF Intake and Behavioral Symptom Scores

The study cohort included 53% males, with 66% White, 23% multiracial, and 11% from other ethnic groups. Compared with those not included in the final analyses, participating children were more likely to have mothers with postsecondary education (79% vs. 66%) and household incomes ≥CAD $100,000 (52% vs. 35%).

At three years of age, children consumed a median of 1,489 kilocalories per day. UPFs contributed to 46% (mean) of total calorie intake. The mean CBCL scores by age five were 45 for internalizing behaviors, 40 for externalizing behaviors, and 41 for overall behavioral symptoms.

Higher UPF consumption at age three was associated with slightly higher behavioral and emotional symptom scores at age five. Specifically, every 10% increase in calories derived from UPFs was associated with small increases in CBCL scores (generally less than 1 T-score point) for internalizing, externalizing, and total behavioral symptoms. Subgroup analyses showed that higher intake of artificially sweetened and sugar-sweetened beverages, breads, and ready-to-eat foods was associated with increased internalizing symptoms.

The researchers reported no evidence that the associations differed between boys and girls.

Substitution Model Findings and Sensitivity Analyses

Conversely, in substitution models, replacing 10% of calorie intake from UPFs with MPFs was associated with modestly lower CBCL scores across internalizing, externalizing, and total behavioral domains. Sensitivity analyses produced similar results, supporting the robustness of the findings.

Conclusions and Public Health Implications

The study’s findings suggest that higher preschool UPF intake may be associated with slightly lower behavioral symptom scores in early childhood. Notably, statistical substitution models indicated that replacing 10% of energy intake from UPFs with MPFs was associated with modestly lower behavioral symptom scores. The results support public health strategies promoting whole-food dietary patterns, including guidance from Health Canada’s Canada’s Food Guide and broader clinical and public health messaging encouraging minimally processed dietary patterns for mental and physical health.

Strengthening early-life nutrition efforts, such as family guidance, childcare nutrition standards, and limits on marketing highly processed foods to children, may support healthy development. Future studies with more precise dietary assessments are needed to clarify long-term behavioral and mental health impacts.