Sounds like your friend may have the start of an eating disorder. Not eating in front of other people and then eating lots in private are symptoms along with a preoccupation with her weight and how she looks. Perhaps the best support you could provide is to tell your friend that what she is doing with food is not healthy and she should talk to a professional about it. Depending on her age, she could talk to her doctor or school counselor who could refer her to a psychologist who works with eating disorders before your friend starts throwing up. Keep encouraging her to go see someone and you could offer to go with her for support.
I need your advice. I have a friend who is stressed out a lot and she doesn’t throw up. But when she is in school, she never eats. When she is at home, she eats and eats and eats, but she won’t throw it up. Then she says she is gaining so much weight. I tell her she’s not, but she insists. So I told her maybe if she didn’t eat so much at night she wouldn’t make herself feel this way. She says she doesn’t think she’s fat, just overweight and chunky. How can I convince her she is not fat? Or is it more than that? Does she need help? Please answer soon.