Those considering how to maintain a healthy weight during holiday festivities, or looking ahead to New Year's resolutions, may want to think twice before reaching for traditional staples like cookies or candy - or the car keys.
A new study by University of Illinois researchers, led by computer science and mathematics professor Sheldon H. Jacobson, suggests that both daily automobile travel and calories consumed are related to body weight, and reducing either one, even by a small amount, correlates with a reduction in body mass index (BMI).
"We're saying that making small changes in travel or diet choices may lead to comparable obesity reduction, which implies that travel-based interventions may be as effective as dietary interventions," said graduate student Banafsheh Behzad, a co-author of the study, published in the journal Preventive Medicine.
Obesity is a multidimensional problem with many social and medical factors, but maintaining body weight essentially is a result of energy consumed and energy expended. Other studies look at the two issues individually, or at a local or individual level, but Jacobson's group wanted to look at both sides of the equation through a national lens. As an outgrowth of previous work examining the relationship between driving and obesity, they decided to use driving as a proxy for physical activity.
"An easy way to be more physically active is to spend less time in an automobile. Any time a person sits behind the wheel of a car, it's one of the most docile activities they can do in a day," Jacobson said. "The automobile is the quickest mode of transportation we have. But a consequence of this need for speed in getting things done may be the obesity epidemic."
The researchers used publicly available data on national average BMI, caloric intake and driving habits. To capture the complexity in the relationship among the three variables, they developed a multivariable model showing how calories consumed and miles driven correlate with BMI.