Obesity and excessive fuel consumption are generally seen as serious but separate problems. But that was before University of Illinois computer science professor Sheldon Jacobson discovered where the blubber hits the road.
Two years ago, Jacobson produced a landmark study reporting that, due to the extra weight we have gained since 1960, Americans were putting 938 million additional gallons of fuel in their passenger vehicles each year.
He noted that, between 1960 and 2002, the weight of the average American increased by more than 24 pounds according to federal government figures. His calculation was limited to the additional amount of energy it takes to transport that additional weight; it did not take into account any indirect effects of obesity, such as a greater propensity by overweight people to drive rather than walk.
Jacobson’s follow-up study, which will be published in the January issue of the journal Transportation Research Part D, concludes that the problem is getting worse. Johnson and co-author Douglas King found that the amount of additional fuel that can be attributed to weight gain increased by nearly 200 million gallons, to 1.14 billion gallons per year.
That accounts for up to 0.8 percent of the fuel consumed by passenger vehicles annually in the U.S. and is a significant factor in terms of greenhouse-gas emissions. “This additional duel consumption causes carbon dioxide emissions of up to 20 billion pounds or more, accounting for up to 0.5 percent of the annual carbon dioxide emissions in the transportation sector,” the report concludes.
Something to ponder while you’re waiting in line at the fast-food drive-through window.