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Depending on who is counting, the number of obese people has reached 20% of the U.S. population, and that number continues to grow. The rate has risen sharply since the middle of the past century, which puts pressure on airlines that have been unable to fly all these people with any ease. And manufacturers Boeing Co. (NYSE: BA) and Airbus have not directly addressed the problem, at least not in a way they have made public.

A 280-pound passenger represents a seating and weight problem a 180-pound passenger does not. The width of an airline seat is typically about 17 inches. Those seated on either side of an obese passenger may have problems beyond the width of the seat.

Hawaiian Airlines tried to remedy the problem of seating for the obese. The effort did not turn out well. According to The Australian:

Hawaiian Airlines is facing a backlash over a new policy to ­allocate seats for heavier passengers flying to American Samoa.

Complaints have been filed to the US Transportation Department against the Hawaiian airline after two American Samoan businessmen alleged they were discriminated against by being told to sit in specific seats.

The complaints were filed in response to the airline’s new policy that no longer allows passengers to preselect seats on flights between Pago Pago in American Samoa and Honolulu. The policy came into effect after the airline noticed that its fuel burn was higher than projected because of increases in the average weight of passengers on that route.

Samoa and American Samoa have some of the highest obesity rates in the world. In 2013, Samoa Air became the world’s first airline to implement “pay as you weigh” flights, which resulted in passengers paying a per kilogram levy for their seats.

Obesity has become a matter of profit.

Will major carriers need to move in the direction Hawaiian Airlines did? With the trend of growing obesity, they will have to.