A common misconception is that somebody has to be anorexic, bulimic, or a compulsive overeater to have an eating disorder. This is not true; that's like saying that you'd have to be flinching if you had a severe headache - it's common, but you can control your outward symptoms. From the way that you place an emphasis on weight, my love, I would suggest that you consider seeing somebody to help. I don't know whether you're in high school, college, or have graduated; if you're in high school, I suggest talking to your parents about you seeing a psychologist - before
a psychiatrist, because the latter deals more in brain chemistry than emotional composition. If you're in college, I'd go to the health center and talk to a psychologist; or, if you're an adult, book an appointment on your own. I think it's really good that you came to us to talk about it.
And your friend sounds like she really cares about you, but just remember - NEVER let anyone force you to do anything, even if it's just eating a sandwich. An eating disorder is a disease which can have symptoms such as starving, purging, and binging; but the reason somebody has the disease is because they are unhealthy - they have some unhealthy emotions that they don't exactly know how to express. That's where friends and psychologists come in.
ALWAYS feel free to e-mail me, and give your friend my e-mail too if she has any questions!
*hugs* I promise that things will improve if you try to love yourself.