There are three major 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 isn't followed by purging.

Nearly all the people affected by eating disorders are teenage girls and young adult women from the middle and upper socioeconomic classes. The causes of the various disorders aren't 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 for Eating Disorders

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 people with anorexia to gain weight. Preliminary attempts to treat bulimia by altering serotonin levels are also promising. In addition, the supplement DHEA might be helpful for protecting bone mass.

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.1,2

Preliminary evidence including one small, double-blind trial suggests that zinc supplements might indeed be helpful in treating anorexia nervosa, possibly enhancing weight gain and helping to stabilize mood.5,20,21 One frequently quoted study often used to discredit the use of zinc in anorexia appears to be relatively meaningless when inspected closely.4,20,21

For more information, including dosage and safety issues, see the full zinc article.

Animal and human studies suggest that when levels of the brain chemical serotonin rise, hunger decreases. People who engage in binge eating may have a different response to changes in serotonin levels.17 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 B 6 significantly reduced binge eating among people with bulimia.18 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.19

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. John's wort might also raise serotonin levels.

For more information, including dosage and safety issues, see the full 5-HTP and St. John’s wort articles.

Women with anorexia often experience bone loss, at least in part due to decreases in estrogen levels. In a one-year long, double-blind study, women with anorexia received either DHEA at a dose of 50 mg per day, or standard hormone replacement therapy.22 The results showed equivalent bone preservation in both groups. However, because there is considerable doubt that hormone replacement therapy is truly helpful for preventing bone loss caused by anorexia,23 these results mean little.

For more information, including dosage and safety issues, see the full DHEA article.

A small trial involving 54 adolescents with eating disorders found that adding 8 weeks of yoga twice weekly to standard therapy was associated with improved eating disorder-related thoughts and behaviors compared to standard therapy alone.24