Gardening increases vegetable consumption in school-aged children: a meta-analytical synthesis

Abstract

Although a handful of published reports suggest that garden-based nutrition education programs are effective in increasing fruit and vegetable consumption, many of these studies have low statistical power because of small sample sizes and lack of long-term data. In this study, we used meta-analytical techniques to examine the efficacy of garden-based nutrition education programs for increasing children’s nutrition knowledge, preference for fruit and vegetables, and/or consumption of fruit and vegetables. We confined our analysis to peer-reviewed studies that examined programs that were delivered to children in the United States. We looked at the relative impacts of garden-based nutrition education programs, compared with experimental controls (i.e., no nutrition education) and nutrition education programs without a gardening component. We compared the results of our meta-analysis with those of a vote counting analysis to illustrate the importance of repeated studies and quantitative analysis. In our vote counting analysis, the majority of the outcomes were nonsignificant in the control and nutrition education groups, but positive and significant for the gardening group. Our quantitative analysis of the impacts of gardening education programs on children’s nutrition knowledge, preference for fruit and vegetables, and/or consumption of fruit and vegetables was limited by the small number of studies that reported the full suite of descriptive statistics needed to conduct a meta-analysis. Nonetheless, one striking and robust result emerged: gardening increased vegetable consumption in children, whereas the impacts of nutrition education programs were marginal or nonsignificant. We suggest two nonmutually exclusive hypotheses to explain our results: gardening increases access to vegetables and gardening decreases children’s reluctance to try new foods. Our results suggest that gardening should be an integral component of wellness programs and policies. A historical lack of funding has impeded both the broader adoption of school gardens and rigorous research on the social, behavioral, and academic impacts of gardening on children. Recently, however, there has been an increase in federal support for gardening and garden-based research projects—a trend that we hope will continue and grow.