One side: if they take up more than 1 seat, they should pay for more than 1 seat.
Other side: people don't choose to be fat, and they shouldn't be punished for their bodies.
People can be fat, but overweight is a different matter. Even people with health problems wont get that big if they do something about it. I agree with the majority, you need more space then pay more. Really.
yes we should pay more,, i've been work as a customer service in one of largest airline in asia (airline official for MU), and they do apply about this issue since they first fly.
But sometimes Its maddening me see regulation that made on Airline with tag line low cost carrier, 'cause they seems could get more expensive than to a regular airline.