^^^^ That is the point I was making, this isn't necessarily about being OBESE, there are a lot of tall large 'healthy' weight people out there who are shoehorned into a thin seat with not enough leg room. If we are truly going to start charging according to weight or volume then it is only fair that those who pay more because of their size should get more room in their seat. How are the airlines going to deal with that, why should a child who pays next to nothing get a big roomy seat when someone tall who has paid the highest fair has to wedge himself/herself into the same size seat?
If we are going to treat pax like we treat frieght then we should follow the same process, you get the space/volume on the aircraft that you pay for.