Just when you thought airlines couldn't do anything else to lighten the load, here comes a new idea: Japan's All Nippon Airways is now asking passengers on select flights to empty their bladders before boarding.
That's right: at the gate ANA staffers encourage fliers to make that one final dash to the restroom to expel some of that extra weight.
"If the flight is lighter, we use less gasoline which is good for the environment," ANA North America spokeswoman Jean Saito told ABC News.
It might not seem like much, but the human bladder can hold up to 16 ounces before the urge to urinate. That's about 1.1 pounds of fluid. If all 216 passengers on an ANA Boeing 767 had pretty full bladders, that extra urine would weigh about 240 pounds.
Just add it to the list of weight and cost-saving cuts the airline industry has made recently. Airlines have already taken away blankets, magazines and even televisions on flights all in the name of reducing weight to save fuel and of course money.
"I think it's going to win them more humor on late night television than anywhere else," said Edmund S. Greenslet of The Airline Monitor. "Clearly everybody is looking pinch pennies if not nickels and dimes but this strikes me as a bit much."
"It's seems to me that if there is money to be saved in terms of operations, there's probably some more fruitful places to look," he added.
Passengers can be at least assured that even for those who can't "hold it," ANA won't be charging them for the bathroom, an idea that Ireland's Ryanair has been entertaining.
Back in February, Ryanair CEO Michael O'Leary said the airline was considering charging passengers at some point one British pound -- about $1.60 -- to use the toilet while on the plane. The low-cost airline's thinking goes like this: not everybody uses a bathroom during a flight so why should everybody have to pay for it.
ANA's latest effort is part of a month-long trial called "e-flight." The "e" stands for ecology and the airline is trying to make flying as environmentally friendly as possible. Instead of plastic cups, the airline will use cups derived from plant materials. Paper napkins will come from non-wood products. Passengers will learn more about the environment during the in-flight entertainment.
But the environmental push starts long before then.
While at the gate, ANA staff will introduce the flight as an e-flight and request that passengers lighten their baggage and to go to the restroom before boarding, according to ANA spokesman Justin C. Massey.
"I think it's bit redundant to ask people to relieve themselves," said Rick Seaney, CEO of airfare site FareCompare.com and an ABCNews.com columnist. "Most people, including my family, do it anyway because they hate the cleanliness of the lavatory."
The e-flight is being tested on domestic flights between Tokyo's Haneda International Airport, Okinawa's Naha Airport and Chitose Airport and on one international route between Tokyo's Narita International Airport and Singapore's Changi Airport.
The test period is from Oct. 1 through Oct. 31 and the airline said it will review whether it wants to continue the program.