Anorexia mirabilis, also known as holy anorexia or inedia prodigiosa or colloquially as fasting girls, is an eating disorder, similar to that of anorexia nervosa, that was common in, but not restricted to, the Middle Ages in Europe, largely affecting Catholic nuns and religious women. Self-starvation was common among religious women, as a way to imitate the suffering of Jesus in his torments during the Passion, as women were largely restricted to causing themselves voluntary pain by fasting, whereas holy men experienced suffering through physical punishment.

A fasting girl was one of a number of young Victorian era girls, usually pre-adolescent, who claimed to be able to survive over indefinitely long periods of time without consuming any food or other nourishment. In addition to refusing food, fasting girls claimed to have special religious or magical powers.