People already know being fat sucks and isn’t healthy. Some people are certainly doing their best to delude themselves and others into thinking they’re good, but I certainly have never been in a conversation with one where the topic’s been brought up.
Here’s the thing, people do plenty of unhealthy and shitty things. Are you going to start lecturing all the cigarette smokers you see? Probably not because it’s just douche-y and pointless. Even if a vocal minority of cig smokers started claiming it was healthy, it still wouldn’t warrant you imposing your wrath onto a random group of normal smokers.
A person coming up to me and criticizing my coke habit would be pretty irritating and that doesn’t even touch on my personal appearance. “Shaming” people for their personal unhealthy habits is just a dick move for no reason than to punch down.
I’m sure there’s some middle ground between health at every size and fat people hate.