My friends didn't suspect a thing until I was ~16 BMI and had uncontrollable crying spells all the time. After moving to another country to study and living (and mostly being) all alone for over 4 years, I snapped into anorexia.   The thing is, I didn't want people to know, because once they knew, they'd worry and do something about it, and I couldn't stand making them feel sad or worried for something I have done. I really didn't want help or sympathy, because in my crazy malnourished depressed mind, I wanted to lose more and restrict more. I was just ready to die for it and they'd take my purpose away from me. And I felt like ultimate trash for doing this "on purpose" to myself, while there are people starving or wishing they had what I have (even if I wasn't rich by any means). I'm also not over-privileged, but having been through this uncontrollable mental hell, I refuse to believe someone could just fake something so horrible and honestly, almost deadly.