Frequency of consumption of fruit and vegetables in 4-year-old children was inversely associated with internalizing and externalizing behaviors, whereas frequency of consumption of sweet/salty snacks was positively associated with externalizing behavior, independent of maternal education, financial difficulties, and maternal mental health.
Frequency of vegetable consumption in 4-year-old children was inversely associated with internalizing behavior.
Total frequency of fruit and vegetable consumption was inversely associated with both internalizing and externalizing behaviors in 4-year-old children.
Frequency of sweet and salty snack consumption was positively associated with externalizing behavior in 4-year-old children.
The study was a secondary cross-sectional analysis of a randomized controlled trial (Early Food for Future health study) originally designed to improve diet at ages 6–12 months.
The associations between diet and child behavioral outcomes were independent of key socioeconomic and maternal mental health confounders.
This research suggests that what 4-year-old children eat is linked to their mental and behavioral health. Children who ate fruits and vegetables more frequently showed fewer signs of both internalizing behaviors (such as anxiety or withdrawal) and externalizing behaviors (such as aggression or rule-breaking). Children who consumed sweet and salty snacks more often showed more externalizing behavioral problems. These associations held up even after accounting for factors like how much education the mother had, whether the family had financial difficulties, and the mental health of the mother. The study was conducted in Norway as part of a larger trial called the Early Food for Future health study, and involved 363 children and their mothers. Diet was measured using food frequency questionnaires, and behavior was assessed using a standardized tool called the Child Behavioral Checklist (CBCL). Five dietary scores were created covering vegetables, fruits, combined fruit and vegetables, sweet/salty snacks, and soft drinks. This research suggests that encouraging healthy eating habits — particularly more fruits and vegetables and fewer sweet and salty snacks — early in childhood may support better behavioral and emotional outcomes. However, because the data are observational and cross-sectional, it is not possible to determine whether diet directly causes these behavioral differences. The authors call for intervention studies to test whether improving children's diets can actually reduce behavioral problems.
Øverby N, Hillesund E, Helle C. (2026). Associations Between Aspects of Diet and Internalizing and Externalizing Behaviors in Children Aged 4 Years.. Nutrients. https://doi.org/10.3390/nu18091461