The study authors say that communities can invest in mass transit systems as a prevention tool to avoid rising rates of obesity.
Promoting the use of public transit could help reduce obesity rates, based on an analysis of county-level data that appears in the journal Preventive Medicine.
In the study, the authors use health data from the 2009 Behavioral Risk Factor Surveillance System, along with transportation data from the 2009 National Household Travel Survey, which were aggregated and matched at the county level.
This method revealed that a 1% increase in the county population’s use of public transit was associated with a 0.221% decrease in the county’s obesity prevalence, after adjusting for other factors, including commuting preferences, exercise, education level, access to healthcare, and income.
"As local communities seek to allocate public funds to projects that will provide the most benefit to their residents, our research suggests that investing in convenient and affordable public transit systems may improve public health by reducing obesity, thereby providing more value than had been previously thought," study author Sheldon H. Jacobson, professor of Computer Science at the University of Illinois Champaign-Urbana, said in a statement.
The reason why using public transit affects obesity is straightforward—as anyone who uses a fitness tracker knows, it takes a certain number of steps to go from one’s front door to a bus stop or train, and a commute may involve a transfer between buses or a train to a bus before arriving at work.
“Alternatively, if they had driven a car, they might simply drive directly from their home to their destination and eliminate the walking portion of the trip,” Jacobson said.
Previous work by Jacobson and co-authors shows that reducing daily driving by even 1 mile a day can lead to a reduction in body mass index. Co-authors on the study are graduate student Zhaowei She and Douglas M. King, a lecturer of industrial and enterprise systems engineering.
"By viewing this link at the county level, we provide a national perspective by considering data from counties throughout the United States," King said. "Our research suggests that, in addition to benefit to the environment and greater access to transportation for residents, community-level investments into public transit systems may also benefit public health by reducing obesity rates."
She Z, King DM, Jacobson SH. Analyzing the impact of public transit usage on obesity. Prev Med. 2017;99:264. DOI: 10.1016/j.ypmed.2017.03.010