Doctors do a lousy job, overall, at setting target weights for people recovering from anorexia. Most set them way too low, so the patient never reaches or stays at a weight high enough to heal from prolonged malnutrition, and relapses.
Now a new study published in the International Journal of Eating Disorders suggests a different measure of recovery: resumption of menstruation.
As nearly any pediatrician or parent can tell you, this is a bad idea. Really bad idea. Some girls never lose their periods no matter how much weight they lose. Some get them back while they're still significantly underweight. Getting your period back while you're in recovery is a good sign, but it's no litmus test of health.
In fact there is no single measure of restored health. Some clinics use body composition analysis, which takes into account not just a person's weight or BMI but also the percentage of lean and fat tissue in the body.
I think the best measure is mental health, and parents are well-placed to judge it. They know what their child was like before anorexia, and they know when their child is "back." I've heard countless stories of teens who reach the weight the doctor sets and still aren't better, or who get their periods back despite still being in the grip of anorexic delusions and obsessions.
When I saw my daughter's anxiety around food and eating was pretty much gone, I knew she was close to full recovery. Don't settle for anything less.