Background: Insufficient consumption of fruits and vegetables in childhood increases the risk of future chronic diseases including cardiovascular disease.
Objectives: To assess the effectiveness, cost-effectiveness and associated adverse events of interventions designed to increase the consumption of fruit and/or vegetables amongst children aged five years and under.
Search methods: The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library Issue 2, 2010, MEDLINE (1950 to 2010 April week 4), EMBASE (1947 to 2010 week 18), CINAHL (up to 12 May 2010), PsycINFO (up to 12 May 2010) and Proquest Dissertations and Theses (up to February 2011) were searched to identify eligible trials, as well as electronic trial registers (also up to February 2011). The reference lists of included trials were reviewed and handsearches of three international nutrition journals were also performed. Authors of all included trials were contacted in order to identify further potentially relevant trials.
Selection criteria: We included randomised controlled trials (RCTs), including cluster-randomised controlled trials, of any intervention primarily targeting fruit and/or vegetable consumption among children aged five years and under and incorporating a biochemical or dietary assessment of fruit and/or vegetable consumption. Two review authors independently screened the titles and abstracts of identified papers. A third review author with expertise in review methodology resolved any disagreements regarding study eligibility.
Data collection and analysis: Two review authors independently extracted data and assessed the risk of bias of the included studies. A third reviewer resolved disagreements between review authors. Fixed-effect models were used to perform meta-analysis for the primary review outcomes where a sufficient number of trials with suitable data and homogeneity were identified.
Main results: Five trials, with 13 trial arms and 3967 participants were included in the review. Two trials examined the impact of specific feeding practices (e.g. repeated food exposure) in increasing child intake of a target vegetable. Two trials assessed the effectiveness of home visiting programs implemented in disadvantaged communities and one trial investigated the effect of a preschool-based intervention in increasing child fruit and vegetable intake. Risk of bias of included studies was low although three of the five trials were judged to be at high risk of performance bias. Meta-analysis of two trials examining repeated food exposure versus a no intervention comparison found no significant difference in target vegetable consumption in the short term (mean difference (MD) 1.37, 95% confidence interval (CI) -2.78 to 5.52). Coupling repeated food exposure with a tangible non-food or social reward, was effective in increasing targeted vegetable consumption in the short term based on one trial. Home visiting programs provided to disadvantaged groups did not significantly increase overall fruit intake in the short term (standardised mean difference (SMD) 0.01, 95% CI -0.09 to 0.11). Similarly, a multi-component preschool-based intervention failed to significantly increase child consumption of vegetables, but did report a small significant increase in mean child consumption of fruit, six months following baseline assessment. None of the trials investigated intervention cost-effectiveness or reported information regarding any adverse events or unintended adverse consequences of the intervention.
Authors' conclusions: Despite the importance of encouraging fruit and vegetable consumption among children aged five years and under, this review identified few randomised controlled trials investigating interventions to achieve this.