The Digester

Early ultra-processed food intake tied to childhood behaviour problems

Mar 4th 2026

A Canadian longitudinal study found that higher intake of ultra-processed foods at age three was associated with greater emotional and behavioural difficulties at age five, with stronger effects for sugary drinks and convenience meals and potential benefits from swapping some ultra-processed calories for whole foods.

  • Study used dietary data from about 2,000 children in the CHILD Cohort Study, assessing diet at age three and behaviour at age five with the Child Behavior Checklist.
  • Every 10 percent increase in calories from ultra-processed foods was associated with higher internalizing, externalizing and total behavioural problem scores.
  • Sugar-sweetened and artificially sweetened beverages and ready-to-eat or ready-to-heat convenience foods showed the strongest associations.
  • Simulated replacement of 10 percent of energy from ultra-processed foods with minimally processed foods was linked to lower behavioural scores.
  • Researchers say findings support early interventions such as parental guidance, childcare nutrition standards and public health campaigns to increase whole and minimally processed options.
  • Study published in JAMA Network Open and funded by the Canadian Institutes of Health Research and a Temerty Faculty of Medicine grant.