"If we drive more, we become heavier as a nation, and the cumulative lack of activity may eventually lead to, at the aggregate level, obesity," he said.
Jacobson chose annual vehicle miles traveled as a proxy for a person's sedentary time because inactivity is most obvious when you are sitting in a car.
"When you are sitting in a car, you are doing nothing, so your body is burning the least amount of energy possible," he said. "And if you are eating food in your car, it becomes even worse."
The sedentary lifestyle that automobile use enables coupled with the prevalent role it plays in increasing the sprawl of our cities, towns and suburbs is the "societal price we pay for always being in a rush to get places," Jacobson said.
"For the last 60-plus years, we've literally built our society around the automobile and getting from point A to point B as quickly as we can. Because we choose to drive rather than walk or cycle, the result is an inactive, sedentary lifestyle. Not coincidentally, obesity also became a public health issue during this period."
Before the automobile became such a prevalent mode of transportation for the vast majority of Americans, "it took much more energy just to live," Jacobson said.
"The way our communities were built, the way we bought and prepared our food, even the heating and cooling systems in our living environments just about everything took more physical energy. Over time, that has been eliminated."
Similarly, in developing nations that are just beginning to incorporate passenger vehicles into their way of life, obesity is on the rise.
"In places like China and India, where the automobile is increasingly competing with cycling and walking as a mode of transportation, they are observing more obesity," Jacobson said.
Jacobson, who also holds appointments as a professor of industrial and enterprise systems engineering, of civil and environmental engineering, a
|Contact: Phil Ciciora|
University of Illinois at Urbana-Champaign