The prevalence of obesity in developed nations is a well-documented phenomenon. But, perhaps surprisingly, obesity rates have also been rising in developing economies. Initiatives to curb obesity are plentiful, but a strategy based in the discipline of city planning merits particular attention, especially in rapidly developing environments where the most impact could be made.
The concept is mixed use development, a model in urban design where the physical layout of a city--the streets, roads and built structures--is composed of numerous interconnected, pedestrian accessible neighborhoods, or zones, each containing a range of buildings that provide services or functions people would normally travel for.
“Like collections of villages where people can live, work and shop in the same area,” says David Osrin, a professor of Global Health at University College London and Senior Research Fellow at the Wellcome Trust.
Naturally, mixed use neighborhoods cannot always provide for every need, and even if they do, people will still need or want to go to places too far away for travel by foot or bike. Where fully active transport proves infeasible, public transport would substitute.
“Connecting these ‘villages’ by active, and public transport will increase levels of activity,” says Professor Osrin.
The link between obesity and our modes of transport may seem tenuous. But, when there is a mixture of places offering a variety of functions within an accessible distance, rates of active transport increase; countries with the highest levels of active transport also have the lowest obesity rates.
Currently, urban infrastructure and policy are predominantly focused on motorized transport. When an economy enters into a stage of growth, appetite for construction and demand for land rise rapidly; cities expand outwards while car ownership increases. Subsequently, the shape of the city, and the way people move within, are incentivized to evolve with motorized transport in mind.
Alongside discouraging activity in already sedentary lifestyles (and thereby amplifying obesogenic factors), overemphasis on motor transport bring other issues like pollution and the resulting effects on the population's health.
Mixed use design, then, can fight obesity through incentivizing behavior. If choices can be shaped by the environment in which they are made, then people can be encouraged to become more active travelers by making it easy to become more active.
The aim of the mixed use model is not to produce a squabbling quagmire of isolated zones where people can only stay within their neighborhood, neither is the goal to eradicate motorized transport. Instead, the mission is to provide opportunities for active transport, such that people are enticed to choose healthier lifestyles.
Having said that, there are no delusions that mixed use development is a cure-all solution to slimming down; neither are the difficulties in its implementation neglected. In mature cities, where the built environment is largely established, modification is required but can be costly. In developing nations, where the most impact could be had, relevant authorities may not hold the necessary political or financial capital to catalyze project momentum. Indeed, in the eyes of certain parties, that a city undergoes development at all may be more important than how a city develops.
In this context, mixed use development is a lens through which to illuminate post-development realities for policy and infrastructural design.
There is also “a growing understanding of the co-benefits [of mixed used development], for goals like decarbonization and increasing social capital. This is an opportunity to undertake a limited set of measures for a common set of aims with a raft of other benefits," notes Professor Osrin,
At its most basic level, obesity arises out of the difference between calories consumed and calories expended. But why people choose the foods that they eat, and what they do with the resulting calories, depend on a cacophony of variables which range from age and ethnicity to socioeconomic status and individual preference. The built environment, however, is a common denominator between disparate factors. Whatever the strategy, it ought to include the very space in which we live and make our choices.
