I'm not obese, so hopefully I can say something about this.
I have mixed feelings about this. It's obvious that it is better to be a healthy weight, but ultimately health is so much more than just weight as demonstrated by the loads of slim women who binge, vomit and/or constantly take any number of pills in the quest to be slim enough to get social approval, and that has zero to do with health, but is no problem. There are obviously many examples of self-inflicted (and expensive) health crises and people don't get emotional about those. So, sorry to not be in on the circlejerk, but I don't believe for a second that this is about health.
I don't know what drives people to eat compulsively so their bodies massively distort like that, or what drives alcoholics or drug addicts, but I'm pretty sure all of those people are in some kind of pain.
I also don't buy the rhetoric that it's about political correctness - they are fat, drunks are drunks, junkies are junkies. I don't think the issue is calling it what it is, I think it's the abject nastiness and intense hatred that gets expressed whenever this topic is raised. No one in everyday life speaks calmly about health problems and what is happening with the obesity problem. People get all worked up and think people who are fat and in obvious pain should die and the world should be rid of having to look at them. Anything other than these people living every day in shame and misery is unacceptable, as though their fatness abrogates their humanity.
I find myself silently judging fat people when I see them on the street, and I wonder why I have an emotional reaction to people who honestly have nothing to do with me. I think about why my first thought isn't related to something like compassion or kindness or is at least neutral. And decent. Of course those people would want to avoid the masses of scorn and hatred that are heaped on them if they could - but for whatever reason, they are struggling and can't manage. Honestly, I think it must have to with me because no fat person has ever done anything unconscionable to me.