Insufficient consumption of fruits and vegetables in childhood increases the risk of future non-communicable diseases, including cardiovascular disease. Interventions to increase consumption of fruit and vegetables, such as those focused on specific child-feeding strategies and parent nutrition education interventions in early childhood may therefore be an effective strategy in reducing this disease burden.
To assess the effectiveness, cost effectiveness and associated adverse events of interventions designed to increase the consumption of fruit, vegetables or both amongst children aged five years and under.
We searched CENTRAL, MEDLINE, Embase and two clinical trials registries to identify eligible trials on 25 January 2018. We searched Proquest Dissertations and Theses in November 2017. We reviewed reference lists of included trials and handsearched three international nutrition journals. We contacted authors of included studies to identify further potentially relevant trials.
We included randomised controlled trials, including cluster-randomised controlled trials and cross-over trials, of any intervention primarily targeting consumption of fruit, vegetables or both among children aged five years and under, and incorporating a dietary or biochemical assessment of fruit or vegetable consumption. Two review authors independently screened titles and abstracts of identified papers; a third review author resolved disagreements.
Two review authors independently extracted data and assessed the risks of bias of included studies; a third review author resolved disagreements. Due to unexplained heterogeneity, we used random-effects models in meta-analyses for the primary review outcomes where we identified sufficient trials. We calculated standardised mean differences (SMDs) to account for the heterogeneity of fruit and vegetable consumption measures. We conducted assessments of risks of bias and evaluated the quality of evidence (GRADE approach) using Cochrane procedures.
We included 63 trials with 178 trial arms and 11,698 participants. Thirty-nine trials examined the impact of child-feeding practices (e.g. repeated food exposure) in increasing child vegetable intake. Fourteen trials examined the impact of parent nutrition education in increasing child fruit and vegetable intake. Nine studies examined the impact of multicomponent interventions (e.g. parent nutrition education and preschool policy changes) in increasing child fruit and vegetable intake. One study examined the effect of a nutrition education intervention delivered to children in increasing child fruit and vegetable intake.We judged 14 of the 63 included trials as free from high risks of bias across all domains; performance, detection and attrition bias were the most common domains judged at high risk of bias for the remaining studies.There is very low quality evidence that child-feeding practices versus no intervention may have a small positive effect on child vegetable consumption equivalent to an increase of 3.50 g as-desired consumption of vegetables (SMD 0.33, 95% CI 0.13 to 0.54; participants = 1741; studies = 13). Multicomponent interventions versus no intervention may have a very small effect on child consumption of fruit and vegetables (SMD 0.35, 95% CI 0.04 to 0.66; participants = 2009; studies = 5; low-quality evidence), equivalent to an increase of 0.37 cups of fruit and vegetables per day. It is uncertain whether there are any short-term differences in child consumption of fruit and vegetables in meta-analyses of trials examining parent nutrition education versus no intervention (SMD 0.12, 95% CI -0.03 to 0.28; participants = 3078; studies = 11; very low-quality evidence).Insufficient data were available to assess long-term effectiveness, cost effectiveness and unintended adverse consequences of interventions. Studies reported receiving governmental or charitable funds, except for four studies reporting industry funding.
Despite identifying 63 eligible trials of various intervention approaches, the evidence for how to increase children's fruit and vegetable consumption remains limited. There was very low- and low-quality evidence respectively that child-feeding practice and multicomponent interventions may lead to very small increases in fruit and vegetable consumption in children aged five years and younger. It is uncertain whether parent nutrition education interventions are effective in increasing fruit and vegetable consumption in children aged five years and younger. Given that the quality of the evidence is very low or low, future research will likely change estimates and conclusions. Long-term follow-up is required and future research should adopt more rigorous methods to advance the field.This is a living systematic review. Living systematic reviews offer a new approach to review updating, in which the review is continually updated, incorporating relevant new evidence as it becomes available. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.