Are you a therapist? Are you the therapist of these individual people? Presumably not. So don't be diagnosing total strangers. You're not qualified to have any idea what motivates someone else.

Plenty of people out there don't have friends or family who validate them or tell them they're beautiful or give them compliments. Since this basic human need is not being met, they turn to the internet. That's not a pathology, it's a response to marginalization and neglect from their communities.

And there are far more destructive things they could be doing.

Let's just go ahead and not armchair-diagnose fat women with a mental illness, ok?