Obesity's fast becoming a problem in the nation's skies. A little extra weight means a little extra cost for the airline. The bottom line of many airlines is being hurt by the expanding bottoms of some passengers.

Dr. Andrew Dannenberg, Disease Control and Prevention: "As the average weight of the American public has gone up and airlines are having to fly more weight."

More weight means higher costs. A survey in 2000 revealed airlines were spending an extra 275 million US dollars a year in fuel costs just to carry the extra weight. Doctor Andrew Dannenberg with the Centers for Disease Control says there is no danger to the public, because the FAA has already factored in extra weight.

Ten years ago, airlines estimated passenger weight at an average 180 pounds. In 2003, they upped the average by ten pounds.

Dr. Andrew Dannenberg: "The average weight of all Americans has gone up by about 10 pounds over the past decade, so the cost of fuel has gone up. It's not large people flying, it's the average weight of all fliers that has gone up."

It's no secret that added fuel costs have contributed to increased ticket prices. Some airlines, like Southwest, are also requiring what they call "customers of size" to pay for two seats instead of one.