Anorexia Nervosa

There are three types of eating disorders: anorexia nervosa, bulimia nervosa, and binge eating disorder. Anorexia nervosa involves compulsive dieting and exercise to reduce weight, leading to dangerous weight loss and, in women, the absence of menstrual periods. Bulimia nervosa is characterized by binge eating followed by purging. The recently-identified binge eating disorder is marked by binge eating that isnt followed by purging.
Nearly all the people affected by eating disorders are teen girls and young adult women from the middle and upper socioeconomic classes. The causes of the various disorders arent known, but it seems indisputable that the current Western emphasis on slimness as a mark of feminine attractiveness contributes greatly.
Because severe anorexia can be life threatening, treatment generally combines a weight-gain program with psychotherapy and, sometimes, antidepressant drugs. Bulimia nervosa and binge eating disorder are both treated with psychotherapy, antidepressants, or appetite suppressants to help control binge eating.

Proposed Treatments:
While there are no well-established natural treatments for eating disorders, there is some evidence that zinc supplements, when used in conjunction with conventional medical treatments, may help individuals with anorexia to gain weight. Preliminary attempts to treat bulimia by altering serotonin levels are also promising.
Zinc
The relationship between anorexia nervosa and zinc deficiency is controversial and the subject of many studies.
Symptoms of zinc deficiency (weight loss, appetite loss, and behavior changes) resemble those of anorexia nervosa to some extent. This has led some researchers to theorize that low zinc levels may be related to the onset of the eating disorder.
Preliminary evidence including two small, double-blind trials suggests that zinc supplements might indeed be helpful in treating anorexia nervosa, possibly enhancing weight gain and helping to stabilize mood. One frequently quoted study often used to discredit the use of zinc in anorexia appears to be relatively meaningless when inspected closely.
Tryptophan
Animal and human studies suggest that when levels of the brain chemical serotonin rise, hunger decreases. Individuals who engage in binge eating may have a different response to changes in serotonin levels. In an attempt to change binge eating behavior, some researchers have tried to alter serotonin levels.
Standard antidepressant drugs are most often used for this purpose. However, it might be possible to achieve similar results with tryptophan and related supplements.
The body uses the amino acid L-tryptophan to make serotonin. Preliminary evidence from a small double-blind placebo-controlled study suggests that a combination of L-tryptophan and vitamin B6 significantly reduced binge eating among individuals with bulimia. This evidence, however, is contradicted by results of another small study that found no significant difference between the effects of L-tryptophan and placebo on binge eating.
Note: L-tryptophan is no longer sold as a supplement due to safety concerns. 5-Hydroxytryptophan (5-HTP) might be a safer option; however, it has not been studied in eating disorders.
The antidepressant herb St. Johns wort might also raise serotonin levels.