Evaluation of the impact of school gardening interventions on children's knowledge of and attitudes towards fruit and vegetables: a cluster randomised controlled trial.

Involvement of children in gardening has the potential to increase liking of fruit and vegetables (FV) and consequently intake, but research results are mixed. School gardening led by external specialists such as the Royal Horticultural Society (RHS) could have more impact than teacher-led gardening on children's knowledge of, and attitudes towards, FV. Data from a cluster randomised controlled trial was used to compare a RHS-led school gardening intervention with a teacher-led gardening intervention amongst 7-10 year olds in 21 London schools. A short questionnaire was developed and used to identify children's knowledge and attitudes towards FV consumption before the garden intervention and 18 months afterwards. Results from multilevel regression models, both unadjusted and adjusted for baseline responses and socio-demographic factors were reported. Attitudes to FV intake were compared between groups. Change in FV knowledge was used to predict change in FV consumption assessed using 24-hour food diaries. In comparison with the RHS-led group (n=373), teacher-led children (n=404) were more likely to agree they ate lots of fruit (p<0.009) and tried new fruits (p=0.045), but RHS-led gardening was associated with a greater increase in the total number of vegetables recognised (p=0.031). No other differences in improvements in attitudes, or associations between change in FV recognition and intake were found. In relation to improvements in children's recognition and attitudes towards eating FV, this trial produced limited evidence that gardening activity packages led by external specialists (RHS-led) provide additional benefits over those led by teachers trained by the RHS. Indeed, the latter were potentially more effective.