Outdoor environment and obesity: A review of current evidence

Obesity is a global epidemic whose management needs long-term, preventive measures. Since the outdoor environment has been linked with obesity, this review aims to summarize data on this association, which may potentially bear clinical implication in the future, i.e., to affect obesity trends by changing the outdoor environment. In this regard, there are increasing data linking obesity with green and open spaces, walkable and bikeable areas, and accessibility to affordable healthy foods and fresh drinking water. Most studies have shown an inverse association of obesity with the availability of safe outdoor green and open spaces, which favor physical activity. Physical activity also seems to be favored by the greater availability of a variety of portable play equipment and the presence of certain fixed playground equipment. The presence of pedestrian walks and aids was also associated with lower rates of obesity, whereas higher proportion of streets was associated with less outdoor activity and higher rates of obesity. Furthermore, higher accessibility and new infrastructure for walking and cycling was associated with greater physical activity and lower rates of obesity. It seems that longer walkable and cyclable areas favor safe walk or ride a bike to work, play or shop, thus lowering the rates of obesity. Moreover, the accessibility to affordable healthy foods and fresh drinking water, and lower consumption of sugar-sweetened beverages have been linked to lower rates of obesity. In this regard, the restriction in public advertisements of unhealthy food and sugar-sweetened beverages may play a certain role towards this direction.