Systematic review and meta-analysis of strategies to increase vegetable consumption in preschool children aged 2-5 years.

BACKGROUND
Most children do not meet daily recommendations for fruit and vegetable intake, and consumption of vegetables remains especially low. Eating habits track from childhood to adulthood hence establishing liking and intake of vegetables is important.

OBJECTIVE
To identify the most successful strategies to enhance vegetable intake in preschool children aged 2-5 years.

DESIGN
The research was a systematic review and a meta-analysis of published studies. A comprehensive search strategy was performed using key databases such as Medline, Embase, PsychINFO, EBSCO and CENTRAL. Articles published between 2005-January 2016, specifically with measured vegetable consumption were included.

RESULTS
30 articles and 44 intervention arms were identified for inclusion (n = 4017). Nine dominant intervention strategies emerged to promote vegetable intake in preschool children. These included; choice, pairing (stealth), education, food service, modelling, reward, taste exposure, variety and visual presentation. The meta-analysis revealed that interventions implementing repeated taste exposure had better pooled effects than those which did not. Intake increased with number of taste exposures and intake was greater when vegetables offered were in their plain form rather than paired with a flavor, dip or added energy (e.g. oil). Moreover, intake of vegetables which were unfamiliar/disliked increased more than those which were familiar/liked.

CONCLUSIONS
Repeated taste exposure is a simple technique that could be implemented in childcare settings and at home by parents. Health policy could specifically target the use of novel and disliked vegetables in childcare settings with emphasis on a minimum 8-10 exposures. The systematic review protocol was registered on the PROSPERO (number: CRD42016033984).