I'm making this it's own post instead of commenting on one cause it's kind of just a rant and it's kind of just me being cranky.
When we fight anti-fatness with phrases like "size doesn't indicate health" it's not about saying that being healthy is the pinnacle of humanness or the bar that needs to be surpassed to deserve respect. It is literally a response to the concern trolling of "I'm just worried about your health" and shit.
It is responding to that specific criticism and trying to spread that knowledge to people who genuinely are concerned about their/their loved one's health solely for the reason of them being fat. It is about counteracting the narrative that being fat is inherently unhealthy, slobbish, an indicator of laziness and a sedentary lifestyle. It is fighting the idea that if a fat person is sick, it is "their own fault" because they have "chosen" to be fat.
It is quite literally trying to decouple the assumed connection between size and health. Breaking that connection is good for everyone, fat and thin, healthy and chronically ill. Once that connection is broken it breaks the assumption that a chronically ill fat person "just needs to lose weight", or that a chronically ill thin person must be "faking it" because they're thin so they "look healthy".
It's not about who deserves respect, it's about society having decided there is a connection that doesn't exist and that connection harming everyone.
So hell yeah people don't have to be healthy to deserve respect. But that's not what the conversation is about in that moment. Because the fat haters aren't saying that fat people don't deserve respect (even though they're acting that way), they're saying that being fat is making a choice to be unhealthy so when they say to lose weight it isn't disrespectful, it's actually caring. They're not talking about the healthiness, they're talking about why they can be assholes without it being bad.