School gardening activities + physical activity improves children’s fruit and vegetable intake but not their weight statusThis study combined a systematic literature review with a meta-analysis to investigate if the combination of school gardening activities and physical activity would decrease childhood obesity measures. The research team—based in China and Malaysia—hypothesized that combining school gardening and physical activity might improve eating habits and reduce obesity more effectively than either intervention on its own. Therefore, they systematically curated and analyzed existing empirical evidence that examined the effects of school gardening or school gardening activities and physical activity on weight and obesity outcomes of primary school children aged 7-12.
For this review, the researchers followed strict protocols to include and exclude relevant research. They searched four research data bases using the same search strings and selected studies based on these inclusion criteria: (1) children attending school, age 7-12, (2) school gardening activities and physical activities for obesity prevention, (3) only school gardening or school gardening combined with physical activity for intervention grounds, only nutritional information or no intervention for control groups, and post-intervention outcomes such as fruit and vegetable intake, body mass index, and waist circumference, and (4) randomized control trials. The researchers also evaluated each study for risk of bias using a standard research protocol. The authors then combined measures from selected studies as appropriate to conduct a meta-analysis of their combined findings.
This review only identified 14 studies meeting their selection criteria. 12 experimental studies were based on a school garden intervention alone. 2 studies combined school gardening activities and physical activity as an obesity intervention. The overall risk of bias was low for most of these studies. School gardening activities significantly improved children’s fruit and vegetable intake but had no significant effect on measures related to body mass and overweight. In the two studies which combined school gardening activities with physical activity, the researchers documented significant increases in children’s vegetable intake motivation, vegetable preference, vegetable intake, taste of vegetables, and nutritional knowledge. Both the school gardening group and the physical activity group had a significantly lower proportion of children classified as overweight and obese compared to the group of children who received no intervention. However, there was no significant difference in the proportion of overweight and obese children when comparing the group who participated in both school gardening and physical activity against the group who received neither intervention.
Ultimately, combining school gardening activities with physical activities did not improve childhood obesity measures like the researchers expected. However, the results of their review and meta-analysis validate school gardening activities as effective interventions to increase primary school children’s fruit and vegetable consumption and improve their intake motivation, attitude, and preference for vegetables and fruits. Based on these mixed results, the researchers speculate their findings may have been different had there been more comprehensive studies that combined school gardens and physical activity. Similarly, the studies that combined school gardening and physical activity only utilized low intensity exercise—not moderate to high intensity physical activity, which could have been more effective. At this point, however, the evidence suggests that combining school gardening with physical activity increases children’s willingness to eat vegetables more than it decreases numbers of overweight and obese children.
The Bottom Line