To add to this: pretty much nobody thinks skinny people are attracted. It's a constructed ideal that many want to achieve, but few want to see in a potential partner.

Source: used to be skinny and bullied for it

Btw it also feels like shit. You're tired all the time, you're cold all the time, when you sit on something solid, like wood, it hurts because there's no fat between your pelvis and the chair, and that'll give you back pain.

Just thought this was relevant because 'it's unhealthy' is sometimes too abstract for people to care