Because this isn't a preoccupation with self image and people with it aren't overeating, avoiding or purging food. Consciously anyway.

I asked my mother and she said although it says eating disorder in it's name, it technically isn't, it's a type of sleep disorder.

I'm writing up a thing about eating disorders and I don't know whether to put it on the list or not!?

So I would imagine it's a hybrid disorder.

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I'd count it as both. Clearly, the subject has some sort of a want for food, hence the sleep eating, but it's also a sleep disorder.

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