An estimated 1.1 percent to 4.2 percent of females have bulimia nervosa in their lifetime.
Symptoms of bulimia nervosa include:
- Recurrent episodes of binge eating, characterized by eating an excessive amount of food within a discrete period of time and by a sense of lack of control over eating during the episode
- Recurrent inappropriate compensatory behavior in order to prevent weight gain, such as self-induced vomiting or misuse of laxatives, diuretics, enemas, or other medications (purging); fasting; or excessive exercise
- The binge eating and inappropriate compensatory behaviors both occur, on average, at least twice a week for 3 months
- Self-evaluation is unduly influenced by body shape and weight
Because purging or other compensatory behavior follows the binge-eating episodes, people with bulimia usually weigh within the normal range for their age and height. However, like individuals with anorexia, they may fear gaining weight, desire to lose weight, and feel intensely dissatisfied with their bodies. People with bulimia often perform the behaviors in secrecy, feeling disgusted and ashamed when they binge, yet relieved once they purge.
http://www.nimh.nih.gov/health/publications/eating-disorders-facts-about-eating-disorders-and-the-search-for-solutions.shtml