Insufficient fruit and vegetable consumption represents a considerable health burden in developed countries. Consumption of fruit and vegetables is associated with reductions in the risk of future chronic disease. Early childhood represents a critical period for the establishment of child dietary habits. Interventions to increase consumption of fruit and vegetables in early childhood may, therefore, represent an effective strategy in reducing the disease burden associated with insufficient fruit and vegetable intake. The aim of this review was to assess the impact of interventions designed to increase the consumption of fruit and/or vegetables among children aged five years and under. To identify relevant studies, we searched a variety of electronic bibliographic databases and relevant journals, and considered studies cited by trials included in the review. We also contacted the authors of included trials and asked if they knew of other trials which may be relevant. Any randomised trial of an intervention which primarily sought to increase the fruit and/or vegetable intake of children five years of age and under, and included a dietary or biochemical assessment of consumption, was eligible. Two reviewers independently searched for and extracted relevant information from trials included in the review. Overall, 10,740 citations were examined yielding five trials with 3967 participants which met the review eligibility criteria and were included in the review. Of the five trials, two examined child feeding interventions, two examined home visiting interventions and one examined the impact of a preschool-based intervention. The findings of the included studies suggest that repeatedly exposing children to a target vegetable does not significantly increase short-term (< three months) child consumption of the target vegetable. One trial which examined coupling repeated food exposure with a tangible non-food, or social reward, found that such strategies were effective in increasing short-term (< three months) targeted vegetable consumption. Home visiting interventions were found to be ineffective in increasing child consumption of fruit and/or vegetables overall. Although the preschool-based intervention failed to significantly increase vegetable consumption, a small significant increase in mean child consumption of fruit was reported. The review highlights the paucity of randomised trials of fruit and vegetable interventions for children of this age, and the lack of effective interventions evaluated using such designs available to health policy makers and practitioners.
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.
Insufficient consumption of fruits and vegetables in childhood increases the risk of future chronic diseases including cardiovascular disease.
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.
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.
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.
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.
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.