Worried if my friend has an eating disorder?

I'm alarmed because I worry my best friend might have an eating disorder. I know there's no real possible way to know for sure unless she tells me, but I'm alarmed.

I finally brought up the fact that I was worried about her because she might have one. She eats extremely healthy--mostly fruits and vegetables, a little protein here and there. If she eats the wrong thing, she sort of feels like her insides are sick, and she feels she needs to exercise it off. She exercises almost daily on a stationary bicycle. She's 5'7" and the last I knew she was at 123--I think now she's up to 127, and she's very angry and very upset over her weight gain. It makes her feel very miserable, and sometimes she even cries over it.

I don't know what to do. I've brought it up with her. She says she's been obsessed for years, but neither of us know how much obsession is too much. When do you draw the line for a definite eating disorder? And how can I convince her to at least talk to a doctor?

Are you 2 in school? Part of it is just growing up. Is she actually throwing up,taking laxatives, or stopping eating when she feels fat? Does she feel like she has a problem? If so, be there for her. Tell her you will go to the doctor with her. Are you a good enough friend to talk to parents or other relatives? Just keep trying to talk with her and let her know you are there for her. Subtly suggest healthy eating and excersize habits-and rember that muscle weighs more than fat and is healthier. It also burns more calories and helps to raise metabolism. Good luck!

If she is within normal range it may just be normal teenage type concern but that can be the beginning. One can never go wrong in asking. 'go to webmd and look up signs and syptoms and see how many she has. Can't hurt can it? :-)
Can you discuss this with one of her family members? Her Mom or Dad, or sibling. They would be the ones that could ensure she speaks to a doctor or psychologist about this.