A study comparing the brains 32 adult women with Anorexia Nervosa and 21 healthy women has revealed that when the women with anorexia were in a state of starvation they had less brain tissue (especially in grey matter) compared to the healthy women. Those who had the illness the longest had the greatest reductions in brain volume when underweight. Happily, these deficits began to reverse after several weeks of weight gain.
 Brain tissue volume changes following weight gain in adults with anorexia nervosa. International Journal of Eating Disorders [Internet]. 2010 ;9999(9999):NA - NA. Available from: http://dx.doi.org/10.1002/eat.20840