Promoting and sustaining fruit intake among children aged 3–11 years: a before-and-after evaluation of a school-based intervention

PURPOSE: Insufficient fruit intake remains a public health concern in childhood, with potential long-term health impacts. This study assessed the adequacy of a school-based intervention in promoting and sustaining fruit intake among Portuguese children aged 3-11 years. METHODS: A before-and-after study was conducted in a non-probabilistic sample of pre- and primary schools across Portugal. Children participated in 12-week teacher-led classroom activities encouraging fruit consumption using storytelling and gamification strategies. Fruit intake was assessed by students' daily self-reports and teachers' records of portions eaten the previous day, collected at baseline and post-intervention. Regular fruit intake was defined as eating fruit on at least 75% of school days for four consecutive weeks, sustained through completion. A per-protocol approach was applied, with behavioral analysis restricted to children consuming < 3 portions/day at baseline. Pre- and post-intervention differences were assessed using paired Student's t-tests. Kaplan-Meier survival analysis was used to evaluate the timing of regular fruit intake enactment, accounting for the design effect. RESULTS: Among 1016 children (64 schools) with complete pre- and post-intervention data, 357 provided daily records and had suboptimal baseline intake. Over half achieved regular fruit intake at school by week 12, with most gains observed by week 4. Mean overall fruit intake increased from 2.09 (1.12) to 2.44 (1.02) portions/day (p < 0.001). Children previously exposed to the intervention were 2.24 times more likely to meet fruit recommendations at baseline. CONCLUSION: Findings suggest improvements in fruit intake following this school-based intervention, and that repeated exposure may help consolidate healthy eating habits.