"These words we use that have a certain meaning aren't actually what we mean."

I looked through the paper, I get what you are trying to say, but the phrase "healthy at every size" just doesn't work. And neither does the insistence that being fat isn't necessarily unhealthy.

There are some good ideas in there. A reduced focus on weight and focusing on a more holistic approach to health can be good, but weight is still an important factor. But again, that's not at all what the words "healthy at every size" convey. It conveys the idea of a very fat person having no more health problems than the average person, which just isn't the case.

But reading the paper I get the impression that they think there is not necessarily anything wrong with being fat. That fatness is perfectly fine. It's not.

lmao, here's a particularly egregious line from the paper:

The diseases that are associated with higher BMI also occur at low BMI. If fat-ness causes these diseases, why do they exist across the weight spectrum?

"Lung cancer also occurs in non-smokers. If smoking causes lung cancer, why does it exist in both smokers and non-smokers?"

And the story about "Jody" shows someone doing all the wrong things to lose weight. It's not her trying to lose weight that's bad (at 195 anyway), it's the way she tries to lose weight. No shit 1000 calories a day isn't healthy. And avoiding fat and carbs is misguided as well. As for 105 Jody, that's a problem of thinking she's overweight when she's not. That may come from some social stigmas that need to be worked on, but that doesn't mean overweight doesn't exist, and it doesn't mean 195 Jody isn't overweight.

one of the myths is “The HAES model argues that people of every size must be healthy”

I didn't say that. The model says fat people can be perfectly healthy, which just isn't true.