Evaluating the impacts of school garden-based programmes on diet and nutrition-related knowledge, attitudes and practices among the school children: a systematic review

BACKGROUND: Previous evidence suggests that school garden-based programmes (SGBP) may be a promising yet cost-effective intervention to improve children’s knowledge, attitudes and practices (KAP) on healthy eating. This review aimed to summarise and evaluate the evidence available on the impacts of SGBP in addressing diet and nutrition-related KAP among school-aged children. METHODS: Five databases including PubMed, Embase, Cochrane, Web of Science and Scopus were searched until February 2021. Randomised, non-randomised controlled and pre-post intervention studies investigating the impacts of SGBP on at least one of the outcomes of interest including diet and nutrition-related knowledge, attitudes towards fruits and vegetables (F&V), food diversity and dietary practice among school-aged children were included. Study selection and data extraction were performed by one reviewer and checked for accuracy by the other two reviewers in accordance with PRISMA guideline. Quality appraisal for studies included was assessed using American Dietetic Association Quality Criteria Checklist. RESULTS: A total of 10,836 records were identified, and 35 studies that met the inclusion and exclusion criteria were included. This includes 25,726 students from 341 schools and 8 nurseries from 12 countries. Intervention duration ranged from 6 weeks to 4 years with 18 studies involving a varied degree of parental participation. SGBP, which majorly includes school gardening activities, cooking lessons and nutrition education, demonstrated beneficial effects on children’s nutritional knowledge, their attitudes and acceptability towards fruits and vegetables and children’s dietary practices including the actual F&V consumption and dietary diversity. However, the impacts of SGBP on such outcomes were highly influenced by various social and environmental factors including the activities/components and duration of the intervention, parental involvement, sample size, and the age of children when interventions were first introduced. CONCLUSION: These findings suggest that SGBP may be effective in promoting children’s nutritional knowledge, attitudes and acceptability towards vegetables, however, the impacts may vary by the type, the extent, and the length of the programmes, and other factors such as parent involvement. Future SGBP is suggested to implement using a combined multidisciplinary approach targeting the children, parents, and community to effectively promote healthy eating among the children and prevent childhood obesity. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-022-13587-x.