Outcome evaluation of fruits and vegetables distribution interventions in schools: a systematic review and meta-analysis.

Objective: Fruits and vegetables (FV) distribution interventions have been implemented as a public health strategy to increase children's intake of FV at school settings. The purpose of this review was to examine whether snack-based FV distribution interventions can improve school-aged children's consumption of FV.
Design: Systematic review and meta-analysis of articles published in English, in a peer-reviewed journals, were identified by searching six databases up to August 2020. Standardised mean differences (SMD) and 95 % CI were calculated using a random effects model. Heterogeneity was quantified using I2 statistics.
Setting: Population-based studies of interventions where the main focus was the effectiveness of distributed FV as snacks to schoolchildren in North America, Europe and Pacific were included.
Results: Forty-seven studies, reporting on fifteen different interventions, were identified; ten studies were included in the meta-analysis. All interventions were effective in increasing children's consumption of FV, with only one intervention demonstrating a null effect. Pooled results under all classifications showed effectiveness in improving children's consumption of FV, particularly for multi-component interventions at post-intervention (SMD 0·20, 95 % CI 0·13, 0·27) and free distribution interventions at follow-up (SMD 0·19, 95 % CI 0·12, 0·27).
Conclusions: Findings suggest that FV distribution interventions provide a promising avenue by which children's consumption can be improved. Nonetheless, our results are based on a limited number of studies, and further studies should be performed to confirm these results. More consistent measurement protocols in terms of rigorous study methodologies, intervention duration and follow-up evaluation are needed to improve comparability across studies.