School-based schemes were effective at increasing both intake and knowledge of fruits and/or vegetables, and results can be sustained long term. Given the methodological flaws in this review, the authors' conclusions should be considered with caution.

To review the effectiveness of interventions to promote fruit and/or vegetable consumption in children in schools.

The following databases were searched from inception to August 2007 for papers in any language (provided an English abstract was available): PubMed, CAB Direct, The Cochrane Library, Web of Knowledge, IBSS, PsycINFO, EMBASE and BioMed Central. Searches for unpublished literature were carried out via internet resources, contact with experts and contact with organisations in countries known to have a 5-a-day fruit and vegetable programme. Reference lists were scanned for additional papers. Full search strategy and terms were reported in the main report (see Other Publications of Related Interest).

Controlled studies that compared any control condition with a school-based intervention to encourage fruit and/or vegetable consumption in children under the age of 18 years were eligible for the review. Studies were required to report at least three months of follow-up and record one change in intake of fruit and/or vegetables or a change in knowledge, attitude or preference to fruit and/or vegetables. Secondary outcomes of interest included impact on other food intake levels and body mass index (BMI).

Included studies were a mixture of randomised, cluster randomised and non-randomised controlled trials. Studies were carried out in a range of countries; most originated in USA. A wide range of interventions and components were evaluated including free or subsidised provision of fruits/vegetables, school-wide versus classroom-based strategies, teacher and parental involvement and community involvement. Fruit and/or vegetable intake was most commonly measured using food frequency questionnaires or 24-hour recall.

Titles and abstracts were assessed by one reviewer. Full papers were assessed independently by two reviewers. Disagreements were resolved by consensus.

Validity was assessed using a published tool utilised previously in a similar review. No further details were reported.

Studies were allocated to one of two categories to approximate primary (young, five to 11 years) and secondary (older, 11 to 18 years) school age groups. Studies that did not conform to these categories were allocated according to age of most of the children included.

The authors did not report how data were extracted.

A narrative synthesis approach was adopted given heterogeneity of populations, interventions and outcome measures. Studies were grouped according to age group and intervention type and results presented in text and tables. Intervention types were described in detail.

This review included 30 studies (n>70,000): 18 were described as randomised and 12 were non-randomised controlled trials. Follow-up ranged from three months to eight years and was more than 24 months for half of the included studies. Descriptive data on intervention type were reported.

Overall effectiveness: Twenty-two of 30 studies reported statistically significant increases in fruit/vegetable intake at follow-up. The intervention effect ranged from an increase in servings per day of 0.14 to 0.99. No studies reported decreases in fruit/vegetable intake following the intervention. Three studies reported initially significant benefits that were not maintained at follow-up. Five out of seven studies reported significant increases in nutrition knowledge or preferences for fruit/vegetables.

Age groups: Nineteen of 23 studies in younger children reported statistically significant increases in fruit/vegetable consumption during the intervention; 16 studies maintained improvements at follow-up. Five out of seven studies in older children reported statistically significant increases in fruit/vegetable consumption; four were maintained at follow-up.

School-based schemes were effective at increasing both intake and knowledge of fruits and/or vegetables, and results can be sustained long term.

This review addressed a clear question with appropriate inclusion criteria. Relevant literature searches were likely to have minimised publication and language biases. Study selection was fully described; however, a lack of details on data extraction and validity assessment made it difficult to rule out reviewer error and/or bias. Although a validity assessment was mentioned, no further details were reported; therefore, it was not possible to assess the reliability of the primary studies. A narrative synthesis appeared appropriate given heterogeneity between included studies. Pooling of different study designs without explicitly consideration of quality meant that the results may not be reliable. Additionally, seven studies were included in the full report but not the published article as a result of the quality assessment (no further details reported). In conclusion, given the methodological flaws in this review, the authors' conclusions should be considered with caution.

Practice: The authors stated that implemention of effective school-based interventions to promote fruit/vegetable consumption required careful consideration of context-specific factors such as differences in education systems, school meal programmes, producer organisations, supply chains and food cultures.

The authors did not state any implications for research.

No external funding.

de Sa J, Lock K. School-based fruit and vegetable schemes: a review of the evidence. London School of Hygiene and Tropical Medicine, London. 2007.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.