If you can cite an example of that beyond some weird fringe group, I'd be surprised. I think most fat acceptance is more:it's the PC 'being fat is good' message that I have issues with.
I was passed over for a lot of design jobs (design being a field driven often by image), despite being an excellent student, who won a couple of design awards. Yeah, I was fat, but I was a good designer, top of my class. The worst part about being fat is that for a lot of people, they see your fat and it stops there. It's a lot like how black people are often treated. It's a shitty feeling.Acceptance only means that - accepting the fact that we're all different, and except for a small minority of very damaged people, everyone has something positive to bring to the table.
I think all most fat acceptance people want is the same thing racial groups want- for people to look beyond the fat. I don't think when a fat woman interviews for a job at a law firm that she wants the hiring manager to find her fuckable, she just wants her ability to argue a case considered. It's often not.
I guess there is not much you can do, people can think and act how they want, but I can't blame fat people for wanting to see more positive representations of fat people in the media. It does help break some barriers.