Lucy is a hard-working student in her sophomore year at a large university. her friends can't understand how lucy eats so much, yet gains no weight. her weight is normal, she eats meals, and is generally personable. her friends do find it weird that she always has to go to the bathroom after a meal, but lucy just says she has a weak bladder. what her friends do not know is that lucy also eats 4,000–6,000 calories in one sitting at least two times a week. after gorging herself, she then vomits all of it back up. she would best be described as suffering from