The "harsh truth" is that people suffering from obesity need to be protected from such vile treatment somehow,

I think you're right in general, but I don't think "protected from" is a good way to frame it, as though fat people are the passive recipients of attacks, and some stronger force has to come in to save them. (I'm not sure quite what you meant, or even if you were just angry about a bad situation and used the first phrase that came to mind.)

The world would be a much better place if the attacks stopped. I'm not sure what the best strategies are to get people to stop seeing fatness and thinness as moral issues. The long slow grind of bring the subject up again and again with whatever mix of facts and anger seem appropriate seems to be finally getting some traction.