Flying While Fat

Because Air Canada considers "obesity a medical condition, it provides overweight passengers with a free extra seat as long as they present a doctor's note." Gulliver is surprised:

Air Canada and other airlines with policies that say obesity is a medical condition are taking a financial hit for every extra seat they give to overweight passengers. That cost is probably being passed on to other passengers. Perhaps this is only fair. We all subsidise the costs of providing on-board defibrillators for patients who suffer cardiac events on planes. We all subsidise the added medical costs of obese people. Why not airline tickets, too?