The act of forgetting to eat any of your three daily meals. This can be a result of a busy schedule or simply absentmindedness. This is most commonly the case with breakfast but also equally applicable to other meals.
One becomes amnesiarexic only if one is not anorexic in the first place i.e. the act of eating needs to already be part of your daily routine and thus to forget to do so makes one "amnesiarexic".
The most common symptoms of an amnisiarexic person include:
Indulgence in "Brunch"
Chewing of gum, pens or pencil top erasers
Stomach roaring sounds
"I'v been amnesiarexic lately, I keep forgetting to eat lunch because I'm so busy"