A global consortium of public health practitioners and advocates identifies the built environment as both a major contributor and potential antidote to the overlapping crises of escalating obesity rates, under-nutrition and climate change. The research team behind a newly released study in the medical research and news journal, The Lancet, argues that urban form should be a catalyst for physical activity, which could have the equally desirable spinoff benefit of lowering greenhouse gas (GHG) output.
They call for: efficient, reliable public transit to reduce reliance on single- or low-occupancy personal vehicles; infrastructure to encourage and safeguard pedestrians and cyclists; and neighbourhood-based services and amenities that include purveyors of healthy food.
“Changes in commuting from cars to active or public transportation have been associated with reductions in BMI (body mass index),” the report notes. “Reduction in carbon dioxide emissions through reduced motor vehicle use and increased active travel — e.g. bicycling or walking — exceeds the reduction in greenhouse gas emissions that could be expected from increased use of lower emission motor vehicles.”
Hypotheses related to transportation, urban design and land use are just one part of the report, which also addresses agriculture, food production, commercial interests that aggressively market products and/or sway policy makers, and human choices and habits. In exploring the underlying connections between obesity, under-nutrition and climate change, the researchers are also looking for possible fixes.
“Many systems-level interventions could serve as double-duty or triple-duty actions to change the trajectory of all three pandemics simultaneously,” they assert.
Reducing automobile dependency tops the list of actions with dual benefits for environmental and human health. More green spaces and tree canopy could also encourage physical activity and absorb more carbon dioxide.
Urban design catalysts for walking, cycling and other physical activity are perhaps more straightforwardly applied to obesity and climate change than to the dilemma of under-nutrition, which is increasingly manifested as obesity in higher-income countries. However, more mixed-use neighbourhoods and less centralization of employment could counter the scarcity of supermarkets in some urban areas, which have become known as food deserts. Meanwhile, areas with a profusion of fast food outlets — labelled food swamps — can be challenging competition for healthier options, both on price point and product offerings.
“Land-use zoning can create urban environments that promote food systems for healthy and sustainable diets,” the report suggests. “Strategies include the promotion of urban agriculture, government regulation of the location, nature and size of food and restaurant outlets, although the evidence for the effectiveness of this intervention is mixed, and incentivizing food retailers and restaurant outlets that sell healthy products to relocate to low-access areas.”
