Forget the fad diets, it turns out all it takes to lose weight was right in front of us all along. According to a Yahoo! news story, a study conducted at Washington University in St. Louis, ironically entitled "A Silver Lining" found that for every dollar in gas prices could shrink obesity by a whooping 15 percent.

On a personal note, this may sound like a stretch, but I know this to be true. A few years ago, when gas prices began to escalate, I begin walking to my local grocery store about 2 miles roundtrip. Over time, I slowly noticed I dropped a few pounds and that my energy level began to increase. Even more, my arms started to show definition from carrying groceries. The moral of the story and the study? Get out of your car and walk!

The report, written by Charles Courtemanche for his doctoral dissertation in health economics, found that 13 percent of the rise in obesity between 1979 and 2004 can be attributed to falling pump prices.

Gasoline hit a low of less than $1.50 per gallon in 2000 before moving back to a record high of $3.22 in May 2007.

Higher gasoline prices can reduce obesity by leading people to walk or cycle instead of drive and eat leaner at home instead of rich food at restaurants.

Courtemanche said he became interested in the link after rising gasoline prices made him think about eschewing his car for public transport.

"I was pumping gas one day, thinking with gas prices so high I may have to take the Metro," he said, referring to the public transportation system serving the St. Louis area.

Courtemanche said he figured he would get an extra 30 minutes of exercise per day by walking to and from the Metro station.

Obesity, defined as having a body mass index greater than 30, has been considered to factor in as many as 112,000 deaths annually.

U.S. health costs related to obesity are estimated at $117 billion per year as studies sponsored by the U.S. government have linked it with high blood pressure, diabetes, heart disease and stroke.