Who knew there would be a sliver lining to the dark cloud of rising gas prices? Charles Courtemanchey of Washington University in St. Louis thinks there may be a link between the price of gas and the size of Americans' waistlines (PDF file link). He wants to prove that higher gas prices will mean less obesity over time.

A causal relationship between gasoline prices and obesity is possible through mechanisms of increased exercise and decreased eating in restaurants. I use a fixed effects model to explore whether this theory has empirical support, finding that an additional $1 in real gasoline prices would reduce obesity in the U.S. by 15% after five years, and that 13% of the rise in obesity between 1979 and 2004 can be attributed to falling real gas prices during this period.

OK that seems to make sense, particularly in aggregate. Higher gas prices will mean more people will look for alternative ways to go about their daily lives. Even around my neighborhood I've seen more people walking to and from the grocery store. Add up the effects of the marginal changes in behavior in some of the population over all the neighborhoods and you end up with a lot of weight lost.

Still not convinced? Well how about considering some of the ways in which higher gas prices might cause people to drive less. Higher gas prices might translate to smaller waistlines because people will:

• Walk to the bus stop or train station rather than drive themselves to their destination
• Spend more time standing and/or waiting in line at the bus stop or train station
• Walk to the gas station because they ran out of gas. Admit it, you drive around more when the tank is low hoping gas prices will drop a nickel or two by the time you absolutely have to fill up
• Make fewer convenience store trips for spicy Taquitos and a jumbo Pepsi
• Eat lunch in the company cafeteria
• Eat the lunch they brought from home
• Eat dinner at home
• Take a walk or bike ride around the neighborhood when they feel like getting out of the house
• Stay home Saturday and wash the car rather than drive to the car wash

If you think about it higher gas prices really might mean slimmer waistlines for Americans. Can you think of other reasons? Add them to the list.

Have a great weekend, everyone. Get out and get some exercise. America's collective waistline will thank you for it.