This is an interesting topic, the question when eating disorders as we know them today have developed.  Romans eating and throwing up to be able to eat more, is that bulimia? Medieval nuns fasting until they see visions and refuse any food but the host, is that anorexia?  The symptoms can be very similar, but I'm not sure the similitude of the symptoms automatically means it#s the same disease.  Anyway, it's a question I like contemplating.