Low gasoline prices are enabling drivers across the country to rely more on personal vehicles for transportation. An unintended consequence of increased mileage could be increased body mass index, according to research by University of Illinois computer science professor Sheldon H. Jacobson and industrial and systems engineering lecturer Douglas King. They talked with News Bureau physical sciences editor Liz Ahlberg about the connection, with words of advice for those hoping to slim down in the new year.
How are driving and body mass index connected? It doesn’t seem like my commute could affect my weight.
Sitting behind the wheel of an automobile is one of the lowest energy-burning times during a day for most people. Motivated by this observation, our research has studied the association between the average number of miles that people drive and the average adult BMI in the United States. For example, we observed that each percent reduction in annual vehicle miles traveled per licensed driver – which corresponds to around 135 miles per licensed driver per year – is associated with a 0.8 percent drop in the adult obesity rate six years later.
Then how could driving less contribute to weight loss goals?
Most people focus on caloric intake and exercise to reduce their weight. Our research considers another lifestyle dimension by bringing miles driven into the equation. One simple thing our research shows has an impact on body mass index is to cut driving by even 1 mile per day.
BMI is a metric based on weight and height, measured in kilograms per square meter. We found that reducing daily automobile travel by 1 mile per driver is associated with a reduction of 0.21 kg/m2 in the national average BMI after six years. By comparison, we observed that reducing daily caloric intake by 100 calories per person is associated with a 0.16 kg/m2 reduction in the national average BMI after three years. This suggests that for an average person, losing weight by caloric intake reduction occurs twice as fast as miles driven reductions. Together, reducing calories and driving fewer miles per day could make a big difference.
You developed a website to help people see the relationship between their driving, diet and BMI. How does it work?
The website transitions our research findings into a format that people can input their own height, weight, driving habits and caloric intake, and compares their BMI with an average person in the United States with these inputs. They can see how changes in caloric intake or driving impact the BMI for such an average person.
What advice would you have for someone trying to keep a New Year’s resolution of losing weight?
When given the opportunity to not drive, take it. Each minute not spent in an automobile translates into extra physical activity, which translates into more energy expended and more calories burned. Those minutes, even just a few each day, can make a difference over extended time periods. Don’t let those low gasoline prices fool you; what you save at the pump may cost you in a higher BMI. Find ways not to drive, and your BMI may thank you!