about 15 years ago. I went from 212 to 135 in less than a year. It was great until I started eating again!

I think it makes your body extremely efficient--since it's essentially in starvation mode, it stores as much as it can because it doesn't know when you're going to feed it again.
I gained all the weight back I'd lost, plus lots more.

From what I've read, one way to heal it is to exercise. The other, most important way, is to quit starving and start eating right. Your friend is on the right track--she'll just have to be patient.