In the video I watched on this subject, it was called “looks-ism”. It was about how we’re socialized from the time we’re children through popular media to regard those who look different from the mainstream as villains. Visible disabilites like a lack of arms or legs, scars, limps, and various other deformities get marked as villainous on the stories we get told from cartoons, to action, and superhero movies (think of how many Bond villains had visible deformities!) And being morbidly obese is no different.

But I like your word for it too. Shape-ism. I’m considered morbidly obese at 300 pounds. I was just diagnosed with lipedema. I am a black woman. At my job there is a white man, though, who probably weighs about the same as me, but the difference is that I have a more pleasing looking hourglass shape which some men think is attractive, so I don’t catch even half the strife he probably gets for not having one. An instance where shape-ism can be seen in real time!