The regulation will require someone who can't fit into one seat to pay for two.
It's a matter which has already been looked at by some US carriers, including United Airlines.
After more than 700 complaints from other passengers about having their seat space 'infringed' by fat fellow passengers, United now requires passengers to buy two seats or upgrade to business class, if there are not two spare seats together available.
Southwest Airlines requires customers who cannot fit between two armrests to buy a second seat, though the cost is refundable if the flight isn't full.
The PC term for obese passengers is 'customers of size'.
