If we were in primitive times, those who are overweight would not even survive; so I think the “tax” has decreased.
For air travel, I recommend booking business class. You will be more comfortable, and so will those who sit to the right and left.
I personally am in favor of health insurance premiums that reflect one’s body attributes and lifestyle. I have been running since I was 16 (I am now 62), and it has paid off: I am still fit. I also eat very healthy — always have, depending on the knowledge that I had. I refuse to buy junk food that I keep in my home: in our house, you will not find any cookies, ice cream, chips, or snacks of any kind. For lunch I have a bowl of vegetables (mostly legumes) with some tuna or other fish, with olive oil and vinegar on it. Fish for dinner. I also kayak several times a week and bicycle. I am thin as a result.
Those behaviors are an investment. I would like to see my efforts reflected in lower health insurance premiums. I also never smoked, and don’t feel that I should be forced to subsidize the medical care of those who have not lived a healthy life.
I understand that it is not easy to lose weight, once one has acquired it. It can be done, however. It takes a no-holds-barred “at war” attitude, to coerce your body into accepting that you are in charge of it, and not the other way around; and it is a war, not a battle: the effort must be life-long. Those who make that effort should be rewarded with some of the lower costs that result.