Why do girls around the age of 17 become obsessed about fitness?

Such as dieting (eating no proteins or drinking any milk), and intense fitness training. My good friend is doing this and she's lost 6lbs in one week, with a total weight loss of 15lbs now. She only weighs 114lbs now and she's 5'6". Is it because of insecurities? or because grad is coming up? What can I say to get her to gain weight??? GIRLS OPINIONS would be greatly appreciated.Why do girls around the age of 17 become obsessed about fitness?I say it is easy to tell someone, however, it really depends if they are receptive to you telling them what to do. I don't remember obsessing at 17 but I can say we all have insecurities and at time everyone wants to look their best. Just remind her that healthy weight is with habits and you think she is beautiful when she is happy.Why do girls around the age of 17 become obsessed about fitness?ALL teenage girls are the same not only the 17 year olds. And it is not always about insecurities O_o

Some girls want to be healthy. And what is wrong with wanting to be pretty? I think she is a very nice size and weight. Why tell her to gain weight? If she starts to get WAY too skinny, then you should talk to her.Why do girls around the age of 17 become obsessed about fitness?She wants to impress guys like you. And I would just casually drop a sentence about what size you and all your friends find attractive in girls without directing it at her. Or point to a healthier looking girl and be like woah that girl has the perfect body size.

This is just a phase, she'll get over it eventually.Why do girls around the age of 17 become obsessed about fitness?
haha i wish. that is not how it is. girls arent obsessed about fitness at any age