Anyone who has been diagnosed with an eating disorder in the US has no doubt faced the confusing and labyrinthine process of getting coverage and appealing those denials.

Says an op-ed piece called Starved for adequate care in the LA Times:

The case highlights the issue of "medical necessity" that lies at the core of so many eating disorder-related health insurance battles, and that will be central to any health insurance reform. How does an insurance company decide who is sick enough to warrant treatment or hospitalization? Whom do we hold accountable for decisions about which treatments are "medically necessary" and which aren't?

Answers are hard to come by because insurers deny or severely limit coverage for an eating disorder -- as with all mental illnesses -- based on a medical assessment process that is neither uniform throughout the industry nor transparent...

...The American Psychiatric Assn. has issued clear guidelines for the care of patients with eating disorders (including when to hospitalize and discharge them). Insurance companies, however, are not compelled to follow these guidelines and seldom do. Nor are they required to heed -- or even listen to -- a patient's own doctor. Instead, they use the catchall term "medical necessity" to differentiate those who merit coverage from those who don't, without defining the term.

With insurers ducking behind this meaningless lingo, patients and their exhausted families can only mount appeals, face mediation or sue. But corporate stonewalling, quibbling over claim-filing technicalities and other bureaucratic minutiae often simply wear them down.

Smith's parents lost their daughter to an insidious disease that is much better understood than it once was. But the gap between what doctors and researchers now know about anorexia's deadly risks and how it gets treated in the real world of the health insurance system was, in Smith's case, too wide.
(emphasis mine)

The article is passionate and poignant- but there are heights and weights listed for one of the patients, so if that is triggering, just stick to the portion I've shared here.

For sufferers of eating disorders, who often don't understand how sick they really are, being told "you're not ill" is like being slapped in the face twice. It adds to the guilt and feelings of I-don't-deserve-anything. The road to recovery is long, hard, and rarely straight. Health insurance shouldn't throw obstacles in the way.