Effects of a Fruit- and Vegetable-Enriched Breakfast on Cognition, Attention, and Mood in Primary School Children: A Randomized Controlled Trial

Background/Objectives: Increasing fruit and vegetable (F&V) intake may benefit children’s neurobehavioral development, but randomized evidence remains limited. We evaluated whether F&V-enriched breakfast improves cognition, attention and mood in primary school children. Methods: We conducted a 12-week class-randomized controlled trial in Shanghai, China. A total of 251 children aged 7–11 years received either a daily F&V-enriched breakfast or a standardized control breakfast with comparable energy provision, both centrally prepared and home-delivered. The primary outcome was change in Full-Scale IQ (FSIQ) measured by the Wechsler Intelligence Scale for Children—Fourth Edition (WISC-IV). Secondary outcomes included WISC-IV composite indices, attention-related behavioral symptoms assessed by the Parent Symptom Questionnaire, and mood by the Profile of Mood States—Brief. Analyses followed the intention-to-treat principle with multiple imputation. Results: Among 282 children screened, 251 were randomized, with 243 completing post-intervention assessments and 230 completing follow-up. The adjusted mean change in FSIQ did not differ between groups (mean difference = −0.63; 95% CI −5.15~3.89; p = 0.807). No statistically significant between-group differences in change were observed for other cognitive indices, behavioral symptoms, or overall mood disturbance. Exploratory analyses suggested a greater reduction in fatigue scores among children aged ≤8 years in the intervention group compared with controls. Dietary assessment confirmed higher dietary fiber and carotene intakes in the intervention group at week 12. No intervention-related adverse events were reported. Conclusions: An F&V-enriched breakfast improved dietary quality but did not produce measurable between-group improvements in cognitive or neurobehavioral outcomes over 12 weeks. Exploratory age-specific findings warrant further investigation.