Introduction: Amidst the global obesity epidemic, greenspace is increasingly recognised as a valuable resource for physical activity and an essential determinant of obesity. This umbrella systematic review aims to synthesise evidence from existing systematic reviews to evaluate the relationship between greenspace and obesity-related health outcomes.
Methods: Electronic searches were conducted in PubMed, Web of Science, and Embase (up to July 2024) using comprehensive terms related to greenspace and obesity. Systematic reviews and meta-analyses examining the association between greenspace and obesity in adults were included, and results were synthesised to summarise overall trends using a convergent approach.
Results: The search identified 362 articles (PubMed:264, Web of Science:54, Embase:44), resulting in 313 articles after removal of duplicates. Four reviews met eligibility criteria, and one review was included from backtracking references. Lachowycz and Jones (2011; 60 studies) found a weak or equivocal association between greenspace and weight status. In the meta-analysis by Luo et al. (2018), higher normalised difference vegetation index was significantly associated with lower odds of obesity (OR:0.88; 95%CI:0.84,0.91), while other greenspace factors were not significant. McCormack et al. (2019) reviewed two Canadian studies and found that increased greenspace was significantly associated with obesity rates, although the strength of the association varied by gender. Chandrabose et al. (2018) found no evidence for longitudinal relationships between greenspace and obesity outcomes, despite studies (n=2/5) showing a positive association. De la Fuente et al. (2018) concluded that access to green spaces is generally associated with lower obesity rates, although results varied by demographics and geography. All reviews highlighted high heterogeneity among studies.
Conclusion: The reviews indicate a generally positive association between greenspace and lower obesity rates, although the findings were varied and heterogeneous. Future studies should focus on understanding causal relationships and evaluating long-term effects of greenspace interventions in obesity prevention and management strategies.