Sarah Goodyear is a Brooklyn-based contributing writer to CityLab. She's written about cities for a variety of publications, including Grist and Streetsblog.
But it's the middle class, not the poor who may pay the biggest price.
In China’s rapidly changing urban landscape, the Chinese middle class may be bearing the greatest burden when it comes to the connection between the way their cities are being built and rates of obesity, a new study suggests.
A paper recently published in the journal Preventive Medicine examines the connections between obesity, income, and the built environment in two of China’s major cities, Shanghai and Hangzhou. The research team is headed up by Mariela Alfonzo, an assistant research professor at the NYU School of Engineering and a Fulbright scholar who has spent years developing measures of walkability in the United States and is now expanding that work to China.
Alfonzo and her colleagues found that, as in other countries, there is a link between neighborhood design—their walkability—and levels of physical activity among residents. They also found, however, that the relationship between income, obesity, and physical activity is not a linear one in China. There, the poorest and the most affluent were both less likely to be obese than the middle class.
“Not only did we find that more walkable places are tied to increased walking and less obesity, but we found that middle-income people are particularly impacted by the type of built environment they live in,” Alfonzo writes in an email. “This runs counter to the finding that higher-income people are the ones that are more likely to be obese. We think it's actually the middle class, as they are the ones more likely to live in less walkable places, and are the ones that are adopting fast food/Western diets. The higher-income people can afford to live in walkable places and they are more aware of what actually constitutes healthy eating. The lower-income people are also often still living in the center of town (more walkable) just in smaller/run-down units and don't have access to Western food.”
Obesity in China is a big problem, and it’s growing. According to figures cited by the researchers, a recent study conducted in 10 Chinese provinces found that 34 percent of people between the ages of 20 and 69 are overweight, and it is estimated that one-fifth of all overweight or obese people in the world are now living in China.
The new study looked at three different types of neighborhoods in Shanghai, where 22 million people live, and the relatively smaller nearby city of Hangzhou, with a population of 6 million. The first was the “urban center,” a legacy of pre-20th development. The second was the “inner suburb,” built up mostly in the 1980s and ’90s. The third is the “outer suburb” that has come into being primarily since 2000.
Neighborhoods of each type in both cities were assessed for walkability with a fine-grained methodology adapted from an American model specifically for use in this setting: the Irvine-Minnesota Inventory-China (IMI-C). In addition to the 162 “micro-scale” features counted in the North American setting, where the inventory was first deployed (it includes physical aspects such as benches, street trees, sidewalks, and curb cuts), this version adds another 124 items that are particularly pertinent in the Chinese setting. These include visible air pollution, cars parked on the sidewalk, and blocked bike lanes. The results were analyzed using the State of Place data analytics platform, which Alfonzo has been developing for several years.
The researchers surveyed more than 1,000 people in the two cities, recording their body-mass index (BMI) and asking questions about income, transportation, eating habits, and exercise.
They found that residents in middle-income neighborhoods had higher BMIs, and that those neighborhoods also ranked lower for walkability. Both newer suburbs and older city centers were more walkable.
Alfonzo says that many people in the real estate development industry in China see the benefits of building more pedestrian- and bicycle-friendly communities, but that government regulations and planning guidelines often prohibit such design. “Everyone I spoke to that was involved with real estate development knew what walkability was and knew that it was important,” says Alfonzo. “The government is not quite there yet. They don’t know that walkability affects these things they do want.”
Alfonzo argues that better data could contribute to an understanding of how more walkable places provide economic and health benefits for Chinese society as a whole. She wants to expand her research to look at not just the health impact of urban design in China’s booming cities, but also at the environmental and economic effects. Maybe someday soon, she says, an understanding of those effects will lead to the removal of policy barriers to walkable development in China.