I remembered a TV show from around 15 years ago related to this, but it did show for 6 seasons, so I guess it wasn't too bad.
It's called
Drop Dead Diva, more info here:
www.imdb.com/title/tt1280822/It features Brooke Elliott and Margaret Cho, amongst others.
It's quite cheesy, and of course it's fiction with a sort of fantasy aspect to it. It's a legal drama with a dash of romantic comedy. I normally find that off-putting, but I feel like it portrays heavier individuals in a more positive light than negative. There is ONE brief scene in one episode I remember that could be portrayed as negative, where the main character was hungry beyond belief or otherwise distressed, until she ate some Cheez-Whiz straight out of the can, but I consider it forgivable. It was only one brief scene in the first season, and I don't recall anything like that in any of the other seasons.
Still, for something that came out in '09, I'd say it was very size positive. This was at a time when Target and many other stores didn't feature plus-size mannequins, when more clothing brands didn't feature sizes above 20 or even 12, and the size/body positivity movement was only a fraction of what it is now.
Are there ways they could have done better? Probably, and I think so, but I think it did a pretty good job.
The main character often struggled with perceptions from others, trying to reconcile her new life with her old life, learning that it's not so easy and can't just decide not to be fat, a different perception from a former model who previously used to be mean to fat people. She was often featured as a heroine fighting against forces that seek to shame fat people as well as other nasty actors out there (and often winning!), and overall, ultimately became a much better person.