Sustenance and sustainability: maximizing the impact of school gardens on health outcomes

School garden programmes have become popular action-oriented learning environments in many countries, often driven by converging priorities of environmental sustainability and healthful diets. Many of these programmes have assessed the impact on dietary intake, specifically fruit and vegetable intake, and related dietary behaviours, such as knowledge, preference, motivation, intention and self-efficacy to eat and prepare fruit and vegetables. The objective of the present study was twofold: (i) to review published garden-based programmes conducted in schools targeting dietary intake and/or determinants of dietary behaviour in children; and (ii) to identify similar strategies and components employed by these garden-based programmes. The review included thirteen studies that have examined the impact of garden-based programmes conducted in school, either during school hours or in after-school settings, on dietary behaviours in children (kindergarten through 8th grade students). Three of the reviewed studies did not have a comparison or control group and simply evaluated within-group changes after a garden intervention. None of the reviewed studies were randomized, but were assigned based on school’s interest and timing of new school gardens being built. Out of the eleven programmes that examined dietary intake, six found that the programme resulted in increased vegetable intake, whereas four showed no effect. Seven of the eight studies that measured preference found that the programmes resulted in increased preference for vegetables. Gardening programmes also resulted in improved attitudes towards, willingness to taste, identification of and self-efficacy to prepare/cook fruit and vegetables. Similar strategies/components employed by the majority of the programmes included: ‘hands on’ curriculum, incorporation of a cooking component, providing the instructors, parental and stakeholder support, food provision and using the garden as the focal point for media promotion. Some of the garden programmes resulted in increased vegetable intake, which has positive implications for both environment sustainability and health-related outcomes. Further, the majority resulted in some improvement in behaviour determinants more generally. However, more research is warranted to understand how to achieve long-term improvements in dietary behaviours and how to sustain the garden-based programmes in schools.