I watched this excellent - perhaps exploitive - documentary program, Super Skinny Me, on BBC America the other night (I'm sure they'll rerun it, they always do, but you can catch the whole deal on youtube).
It's about two lady journos who decide to try a variety of crash and fad diets in an attempt to reduce to size 0 in a matter of weeks. At first it's somewhat lighthearted, and the women are in good humor going through ridiculous stunts like exercising in a sauna whilst swaddled in saran wrap - gross! But once they hit on the methods that work - like the master cleanse - they go totally mental, weak with hunger but exhilarated by their dropping weights and pants' sizes. Although they are purportedly participating in an experiment, they are experimenting on themselves, so it's impossible to remain objective or hypothetical. They get hooked on the weight loss, and the disgusting rituals (like frequent colonics - also gross!), and are willing to overlook warnings from their doctors and their disintegrating personal relationships to continue with it.
I thought it was fascinating, perhaps particularly so because I am experiencing uncharacteristic skinniness myself. I am physically unable to eat the way I want to right now for medical reasons, and although I am frustrated by a lack of energy and attention span, and fantasizing about burgers every day, I have to admit to also being quite enchanted by numbers I haven't seen on the scale since before puberty and my increasingly saggy wardrobe. I expect that I will return to my regular weight, activity level, and non-disordered eating as soon as humanly possible, but it will not be completely without regret when I get my old body back.