Anorexia nervosa has significant physical consequences. Affected individuals can experience nutritional and hormonal problems that negatively impact bone density. Low body weight in females causes the body to stop producing estrogen, resulting in a condition known as amenorrhea, or absent menstrual periods. Low estrogen levels contribute to significant losses in bone density.
In addition, individuals with anorexia often produce excessive amounts of the adrenal hormone cortisol, which is known to trigger bone loss. Other problems, such as a decrease in the production of growth hormone and other growth factors, low body weight (apart from the estrogen loss it causes), calcium deficiency, and malnutrition, contribute to bone loss in girls and women with anorexia. Weight loss, restricted dietary intake, and testosterone deficiency may be responsible for the low bone density found in males with the disorder.
Studies suggest that low bone mass (osteopenia) is common in people with anorexia and that it occurs early in the course of the disease. Girls with anorexia are less likely to reach their peak bone density and therefore may be at increased risk for osteoporosis and fracture throughout life.