As far as the most common eating disorders; I guess I'll first mention that really there are three official eating disorder diagnoses that are sort of officially recognized within the mental health community. So that means there are three eating disorder diagnoses that are listed in the diagnostic manual of psychiatry and mental health called the DSM-IV. And those three eating disorder diagnoses are Anorexia nervosa, Bulimia nervosa, and there's a third diagnosis called eating disorder not otherwise specified. Professionals sometimes call it ED-NOS, it's the acronym for short. And so I'll sort of speak about these three categories primarily.
Anorexia nervosa and Bulimia nervosa, we know tend to effect women in much higher proportions than men. It's probably something like a nine to one ratio women to men effected by these problems. And in Anorexia nervosa we know that life time prevalence of this type of problem in women is about 1 percent of the population. Bulimia nervosa, the rates are slightly higher, but still 2 percent of life time prevalence in women. Then we have this third category, eating disorder not otherwise specified. Which is a very sort of heterogenous category I guess you would say. It has lots of different types of eating problems in it. And it might not be surprising to hear that that's the largest category. More people in the eating disorder not otherwise specified category than in anorexia or Bulimia nervosa. And probably both of those combined. So eating disorders not otherwise specified encompasses lots of other types of eating problems.
One that is very prevalent is binge eating disorder. So that probably encompasses people that present to obesity and weight loss clinics. Maybe up to 30 percent of those people presenting to those clinics may have some type of binge eating disorder problem. So binge eating disorder is a repetitive pattern of repeated engagement in episodes of binge eating and a binge we sort of officially define as engaging within a fixed period of time, maybe a two hour period, engaging in eating a large quantity of food. Much larger than what most people would consider appropriate for a normal meal, with an associated sense of loss of control with that eating event. So many of us have sat down and eaten a good bit more than we thought was appropriate for a normal meal, maybe at Thanksgiving dinner by the way, you know, for example. But when there's that sort of sense of loss of control around it and when it's happening on a repetitive basis. That is sort of the essence of binge eating disorder.
And there are other problems that are encompassed within that eating disorder not otherwise specified category right now. Problems like night eating syndrome. Problems like purging disorder where there's purging behavior like vomiting in the absence of binge eating behavior. And other types of problems that kind of look Anorexia nervosa and Bulimia nervosa but maybe aren't quite as severe or a little bit different in the way they present and don't meet those sort of strict criteria for those two groups. Whatever the eating problem, the most important thing is to try to acknowledge that a problem is going on and to reach out to a treatment center or a mental health professional in order to get help from the problem.