Cutting back on car travel can be just as effective for losing weight as cutting back on calories, according to mathematics researchers at the University of Illinois.
Health experts agree that Americans’ reliance on cars, especially for short trips, has contributed to the obesity epidemic because driving or riding in a car expends as little energy as possible. Getting out of the car for just one mile a day would equal two to five minutes of more active pursuits and could be as effective as reducing the daily diet by 100 calories.
Such a small lifestyle change at the population level can lead to a reduction in U.S. obesity rates, according to the study led by computer science professor Sheldon Jacobson that was recently published in the journal Preventive Medicine.
Jacobson suggests parking in the farthest space in the lot to increase walking distance, or walking to the bus stop to use public transportation. Daily choices matter, he said, with driving as well as dietary habits.
The researchers looked at body mass index, automobile miles and calorie intake from national surveys and government data to create a math model on the relationships among food, driving and adult weight. Not surprisingly, an increase in calories consumed results in an increase in body weight. But the number of miles traveled by car can have the same or greater effect.
The researchers calculated that the body mass index of the average American (now measuring 27.6) could be lowered by 0.2 after six years of driving one less mile a day. By comparison, cutting the diet by 100 calories a day could reduce the average body mass index by 0.16.
While those differences are small, it could mean the difference between healthy and overweight for many people. Even small decreases in body mass index are associated with lower health care costs.
Obesity is commonly thought of as a medical problem, but the research points to societal solutions, Jacobson said. His research team previously calculated that the country’s obesity epidemic contributes to an additional 1 billion gallons of gasoline consumed, because cars burn more fuel with heavier passengers.
“The obesity issue is multi-dimensional, and if we focus purely on medical interventions without taking into account the social issues, we’re not fully exploiting our tools to address the problem,” Jacobson said.