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Activity-Friendly Environments and Obesity
Overview
In the U.S., physical inactivity is a major cause of the increase in obesity. Considerable research has been produced in the last 10 years - most of it funded by the Robert Wood Johnson Foundation[1] - that shows the way streets and neighborhoods have been built and maintained can greatly influence the physical activity and obesity levels of its residents. The absence of parks, trails, and other recreational facilities also reduces physical activity. To address the obesity epidemic, it is critical that neighborhood form and transportation systems be rethought and transformed over time.
Most Adults are Sedentary
Health officials recommend adults get at least 30 minutes of moderate to vigorous physical activity per day. However, only 49% of U.S. adults surveyed say they meet that recommendation. [1] One-third report getting no physical activity whatsoever, with inactivity rates highest among African-Americans and Hispanic populations. Accelerometer data, which doesn't rely on self-reporting, but rather records actual movements, indicates only 5% of adults meet the minimum. Actual results are probably somewhere in between.
Why are we so inactive? Other research suggests the built environments we work, live, and play in make choosing physical activity difficult, and sometimes almost impossible. High levels of screen time, labor-saving devices in the home and workplace, and hours spent behind the wheel of a vehicle have dramatically reduced the number of calories burned in the course of an average day.
Sedentary Behavior Leads to Obesity
As physical activity has declined, obesity has increased substantially. Obesity in adults has increased from 13% to 32% between the early 1960's and 2004. A total of 66% of U.S. adults are overweight or obese. The rate is even higher among women and minorities. [2]
Neighborhood Design Influences Physical Activity
According to the federal Centers for Disease Control and Prevention (CDC), creating, improving, and promoting places to be physically active can increase by 25% the number of residents who exercise at least three times a week. [3] Conversely, the lack of such features inhibits physical activity. The studies that support this conclusion include the following:
- 98% of surveyed users of a newly built trail in a rural West Virginia community reported they were inactive before the trail was opened. [4]
- Five studies in the United Kingdom suggest that traffic calming treatments were associated with a greater sense of safety among residents, and with increases in walking and bicycling. [5]
- A similar study in a low-income area in North Carolina found that 20% of adults walked more after
traffic calming
was installed.[6]
- Several studies have shown adults are more active when there is a park or recreation facility in the neighborhood.[1] This association is often found to be stronger in low income or minority communities. In general, low income communities have less access to activity--friendly environments. Investments such as sidewalks, trails, biking facilities, and parks may therefore be most warranted in low income neighborhoods.
- A large number of studies link community design and transportation planning to activity levels of adults. For example, the presence of sidewalks and other measures of walkability are associated with significantly higher rates of walking.[1]
- Studies in the United Kingdom showed that opening new
physically separated bike lanes
on three sections of the national bicycle network increased cycling by 43%, 50.1%, and 29.7%, respectively.[7]
Activity-Friendly Environments & Obesity Rates
Studies show that activity-friendly neighborhoods not only increase physical activity but also exhibit lower obesity rates.
- A 2003 study covered widely in the media showed that residents of more compact, higher-density counties walked more and were less likely to be obese than residents in more sprawling counties.[8]
- A 2004 study in Atlanta found that residents of more walkable neighborhoods were 35% less likely to be obese than residents of the least walkable neighborhoods.[9]
- Two studies, one in Atlanta[9] and another in California[10] showed that the likelihood of obesity goes up substantially with the amount of daily driving. In California, the rate of obesity among those who drove the most was 27%, but only 9.5% among those who drove the least.
Change the Way We Build Communities
Two diverse federal panels, the Transportation Research Board/National Institutes of Medicine [11] and the Task Force for Community Preventive Services [12] reviewed the available studies on the link between neighborhood form and physical activity. They both concluded there is a consistent correlation between land use patterns and how active people are. They both also recommended changes in zoning and other development regulations, and transportation investments that would encourage the development of more walkable communities.
ALSO ON THE LIVABLE STREETS NETWORK
- Obama: I'll Boost Funds for Ped-Bike Projects if Elected. Streetsblog, June 16, 2008.
- Autobesity: We Have a Driving Problem. Streetsblog, November 13, 2007.
REFERENCES
Each source is referred to by the same number every time it is cited. Please keep citation style consistent.
[1] Active Living Research, 2008. Designing for active living among adults. The Robert Wood Johnson Foundation.
[2] Wang, Y. and M.A. Beydoun, 2007. The obesity epidemic in the United States--gender, age, socioeconomic, racial/ethnic, and geographic characteristics: a systematic review and meta-regression analysis. Epidemiological Reviews, 29: 6-28.
[3] Physical Activity Guide to Community Preventive Services U.S. Centers for Disease Control and Prevention, 2009.
[4] Gordon, P.M., et al., 2004. Use of a community trail among new and habitual exercisers: a preliminary asessment. Preventing Chronic Disease, (1):A11.
[6] Evenson, K.R., et al., 2005. Evaluating changes in physical activity with the building of a multi-use trail. American Journal of Preventive Medicine, 28(2S2):177-185.
[7] Cope, A., et al., 2003. The UK National Cycle Network: An assessment of the benefits of a sustainable transport infrastructure. World Transport Policy and Practice, (9):6-17.
[8] Ewing, R., et al., 2003. Relationship between urban sprawl and physical activity, obesity, and morbidity. American Journal of Health Promotion, (18):47-57.
[9] Frank, L.D., et al., 2004. Obesity relationships with community design, physical activity, and time spent in cars. American Journal of Preventive Medicine, (27): 87-96.
[10] Lopez-Zetina, J., et al., 2006. The link between obesity and the built environment. Evidence from an ecological analysis of obesity and vehicle miles of travel in California. Health & Place, 12:656-664.
[11] Transportation Research Board, Institute of Medicine, 2005. Does the Built Environment Influence Physical Activity? (pdf). Special Report #282. Washington DC.
[12] Heath, G.W., Brownson, R.C., Kruger, J., Miles,R., Powell, K.E., Ramsey, L.T. and the Task Force on Community Preventive Services. The effectiveness of urban design and land use and transport policies and practices to increase physical activity: a systematic review. Journal of Physical Activity and Health, (3):S55-S76.
PICTURE REFERENCES
Pictures are cited in the order they appear above. Please keep citation style consistent.
[1] Pedestrian bicycle path. Photo by Dan Burden via Pedestrian Bicycle Information Center Image Library.
[2] Bicycle bridge. Photo by Dan Burden via Pedestrian Bicycle Information Center Image Library.
