I think you’re misunderstanding the fat acceptance movement. It’s about separating the illness from the person, not about obesity health. In our society it would be impossible to be unaware that obesity is unhealthy.

People go out of their way to be mean to fat people. The fat acceptance movement is essentially “please don’t do that”.

It’s both. There is a very vocal contingent who insist that obesity is not unhealthy.

There are people who claim that, yes, but that’s not broadly what the movement is about.

Every philosophy or movement has outliers that misinterpret and act outside of the bounds of that movement and we understand that those outliers don’t represent the group; yet people always look to those outliers with the fat acceptance movement — the fat acceptance movement is not given the benefit of the doubt like others are.

To me that implies that there is underlying bias.

You are doubtless correct that there is bias. (Literally your stated purpose of the movement is to counter this bias.) But with that said, these voices may be outliers, but they are by far the loudest. I’ve seen people claim that “obese” is a slur. I’ve heard more people claim that health is unrelated to weight more than I’ve heard people say that fat people deserve good healthcare.

From my vantage point the movement has largely been co-opted by extremists who want to pretend that obesity is not a health problem.

There is a fine line between being opposed to fat acceptance and thinking performative cruelty works.

(It's does not. It made me so much worse. I have nothing but bad things to say about the medical "professional" who catastrophized my diagnosis to "wake me up" and then shrugged when my response was depressed resignation.)

You can't depend on people being nice to take care of your own health.

There are several studies now showing that symptoms reported by overweight patients are taken less seriously by medical professionals, it’s not just a matter of people “being nice”. It’s actually providing a lower standard of care.

I should clarify that my doctor explicitly lied to me (found out by requesting my medical file after moving) to shock me on purpose because of his own fifth grade understanding of psychology.

Whether patients make good choices is completely independent from whether doctors provide everyone with equal quality of care.

Specifically, doctors are less likely to investigate issues that can be explained by obesity than they are in non-fat people.

For example, if you have high blood pressure and you are a normal weight your doctor will probably look into underlying conditions that can cause high blood pressure. Being overweight is an independent risk factor for high blood pressure but it doesn’t reduce the likelihood of the other risk factors. Doctors are less likely to look into an underlying cause for high blood pressure if you are overweight.

Doctors are probably also less likely to look for other causes of chronic cough in smokers.

In general doctors are looking for the most obvious potential causes of a health problem. If someone on high dose anabolic steroids went to the doctor with him blood pressure, the doctor would probably tell them to cut out the steroids as the obvious answer rather than exploring other reasons the patient’s blood pressure might be high.