Just like we get charged money for each extra bag we bring on a plane because of its added weight, an overweight passenger should be subject to the same charge. Being excessively overweight is a choice. If an airline is constantly raising the prices because of increased gas usage due to the weight of passengers increasing, then those causing this increased usage of gas should be responsible for the financial burden.
It's discrimination to charge someone more money due to something like this. There are simply too many factors to consider when you can just charge everyone the same amount for the spot they chose to sit in. There are plenty of other ways to save fuel and shaming overweight people through extra charge isn't the ideal way to go.
Overweight people should never be treated any different than anybody else. In fact, it may even worsen the obesity problem (depression/stress can lead to weight gain).
Charging more for things doedoes make a "problem" go away. It simply allows it to continue existing. To burn less fuel, reducing weight is ONE way - and determining and treating yht root cause of an individuals obesity is THE ONLY way to solve the obesity problem.
So, cure or treat obesity = save a tiny bit of fuel.
I believe overweight individuals should not be charged extra. I see this argument in a similar light to someone who is excessively bulky from working out, or someone who is significantly taller than average: Should you charge that person extra just because he or she breaches out of the 17-inch confines of an airline seat? I don't think so. I think that's discriminatory.