Obesity is emerging as a significant health concern for children and adolescents in countries across the world. Interventions for preventing and/or treating this concern often focus on increasing children's physical activity levels. Related research includes investigations into how access to green space might influence individual physical activity and subsequently weight status. Findings from related studies have been inconclusive.
This systematic review of the academic literature and meta-analysis analyzed studies examining the association between access to green space and weight-related behaviors and/or outcomes in children and youth. Studies included in the review were published prior to 2019, were conducted in nine different countries, and included sample sizes ranging from approximately 100 to over 44,000. Studies included in the review used different measures of access to green space. Such measures included presence of green space, number of green spaces, density of green spaces and distance to the nearest green spaces, which was often measured by geographic information system (GIS) technology. Some of the studies collected information about television-watching time.
Most of the studies found that greater access to green space predicted higher levels of physical activity, healthier weight, and lower levels of television-watching time. The evidence, however, is not sufficient enough to determine a causal association between access to green space and weight status. Such a determination requires longitudinal methodology. Most of the studies included in this review were cross-sectional. A few of the included studies found negative associations between green space and childhood physical activity. The researchers suggest that this may be due to different measurements of green space. Remotely sensed images of greenspace can include spaces not suitable for children's physical activity, such as croplands and marshes. Quality of greenspaces may also influence use of such spaces. Parks that are not well maintained may be perceived as unsafe and thus rarely used by children.
Further research incorporating longitudinal methods is recommended. Such research could be helpful in providing a strong evidence base for addressing childhood obesity concerns.