(HealthDay)— If weight loss is your New Year's resolution, making another vow—to drive less in 2013—could help, a new study suggests.
And for a bonus environmental benefit, less driving (replaced with more physical activity) could reduce U.S. gasoline consumption, which has risen with the obesity epidemic, the researchers report.
"Obesity isn't a one-dimensional issue. There are changes that we can make as individuals that will affect us all at the national level," said study senior author Sheldon Jacobson, director of the simulation and optimization lab in the computer science department at the University of Illinois.
For example, he said, "Driving one less mile a day leads to a lot less fuel being consumed. Obesity isn't just a medical issue, but a societal one. Reducing travel is a way to tackle the obesity epidemic and save fuel."
One expert agreed that it's a positive step, regardless of the motivation behind it.
"If you're making healthy changes like driving less—whether it's to lose weight, or because you want to go green and save fuel—your body doesn't care why you're doing it, you'll still get the benefits," said Samantha Heller, clinical nutrition coordinator at the Center for Cancer Care at Griffin Hospital in Derby, Conn.
The average body-mass index (BMI)—a measure of a person's body fat—in the United States has increased during recent decades, and the national economy has taken a hit with the rise in obesity-related health care costs. In California alone, annual health care costs due to obesity nearly reached $42 billion, according to study background information.
Previous research has estimated that obesity causes as much as 1 billion additional gallons of gasoline to be consumed each year in the United States.
To see what impact small lifestyle changes might have on national obesity levels, Jacobson and his colleagues designed a statistical model to predict what would happen if people drove one less mile a day, or if people consumed 100 fewer calories a day.
The national BMI was 27.55 in 2010. Anything above 24.5 is considered overweight. Thirty and above is considered obese.
The researchers found that if Americans drove one less mile each day, the national BMI would drop by 0.21 points after six years. And, if Americans consumed 100 fewer calories a day, they would lower their BMI by 0.16 over three years, according to the study.
"There is a more direct reduction in BMI from consuming less food, but both of these are very significant changes on a national level. For every drop of 0.1 or 0.2, we start to see more and more people being healthy. And, we're potentially talking about billions of dollars of saving," Jacobson said.
Heller said it's relatively simple to drop those calories from your diet. "That's a banana or a couple of small cookies or one small latte. It's very easy to cut a hundred calories from your diet, and your body doesn't miss [them]," she said.
She also suggested that not snacking after dinner could be a quick way to drop extra calories from your diet. Or, give up your nightly dessert. Small changes can add up fast.
"Focusing on simple techniques that slash calories bit by bit can be very helpful," she said.
The study was published online recently in the journal Preventive Medicine.
Explore further: Study: Curbing car travel could be as effective as cutting calories
Learn about the benefits of weight loss from the U.S. Centers for Disease Control and Prevention.