Scientists measure connection between the built environment and obesity in baby boomers

August 11, 2008

Does your neighborhood have a lot of fast food outlets, few sidewalks, and no parks? If yes, your physical neighborhood may be hampering your ability to be physically active and placing you at increased risk for obesity. According to a research study conducted in Portland, Oregon by scientists at Oregon Research Institute (ORI), neighborhoods with lower mixed-land use and higher densities of fast-food outlets were more likely to have residents who were overweight/obese. In contrast, residents living in neighborhoods with higher mixed-land use, high street connectivity, better access to public transportation, and more green and open spaces were more likely to engage in some form of neighborhood-based walking.

The study was unique in that it focused on the pre-Baby Boom/early-Baby Boom generations (ages 50-75) which will become the major demographic related to healthcare utilization in the next 20 years. By 2030, 36% of the total U. S. population (compared to 24.9% currently), will be over 50, and the numbers of those over 60 will more than double from current levels (ranging from an 82% increase in people aged 60-64 to a 126% increase in those aged 85+). Results from the study, funded by the National Institute of Environmental Health Sciences, are reported in the July issue of the American Journal of Preventive Medicine.

"Findings from this study suggest the significant role that built environment plays in either positively or negatively impacting our health and/or lifestyle," notes study lead Fuzhong Li, Ph.D. "34% of U.S. adults aged 20 and over are obese. Part of the rise in this disease may be attributed to our surroundings -- for example, increased accessibility to unhealthy foods. The built environment is also creating barriers for our ability to exercise: many neighborhood areas lack parks and other recreational facilities and suburbs are often designed to discourage neighborhood walking. Simply focusing on encouraging people to change their lifestyles – to eat better and to get more exercise -- is insufficient. Measures are also needed to improve features of the built environment, which are often modifiable (e.g., via changes in city zoning, development policies), to support people in making such changes." says Li.

ORI scientists studied the built environment characteristics (land-use mix, density of fast-food outlets, street connectivity, & public transit stations, and the presence of green & open spaces) of 120 neighborhoods in Portland, Oregon. Over 1200 residents of the neighborhoods provided the researchers information on their age, gender, education, race/ethnicity, household income, alcohol & tobacco use, general health status, Body Mass Index (BMI), and eating habits. The residents' levels of physical activity were also measured, including neighborhood walking, walking for transportation (to catch a bus), walking for household errands, and moderate or vigorous exercise. All participants were between the ages of 50 and 75.

The results showed significant associations among built-environment factors and the prevalence of overweight/obesity and various forms of physical activity in middle-aged and older adults. These findings suggest the need for public health and city planning officials to consider how modifiable neighborhood-level, built-environment characteristics can create more livable residential communities and promote active, healthy lifestyles.

Source: Oregon Research Institute