Food Addiction Support Group
An individual suffering from a food addiction disorder frequently experiences episodes of uncontrolled eating, or binging, during which they may feel frenzied or out of control. They will eat much more quickly than is normal, and continue to eat even past the point of being uncomfortably full. Binging in this way is generally followed by a period of intense guilt feelings...
I was bullemic for a few months only but it's so much to do with the way your mind works and in a way you start to train your body to follow with it - that cycle needs to be broken.
For me I forced myself to go to counselling which REALLY helped and confided in a trustworthy confidential source that way. Perhaps you can help her get in touch with a counsellor / depending how your system works where you are find a gp, get her 6 free sessions through them or something like that.
Other than that passing on info. that can help her want to change can't hurt at all but it's ultimately up to her as self esteem and image is deeply personal.