The idea is supposed to be “don’t be a shithead to fat people, acting like an asshole to them doesn’t help them lose weight and gain self-confidence” but for some reason that morphed into a kind of “If you say anything negative about a fat person ever, you’ll be accused of being the worst person ever.” Though at the same time, this is mainly just one of those conservatives worrying way, way too much about a tiny group of people who no one would’ve ever heard about had they not gotten so mad at them existing.