Being too thin can occur with anorexia nervosa, other eating disorders, or loss of appetite, and is linked to menstrual irregularity and osteoporosis in women, and greater risk of early death in both women and men. Many people -- especially women -- are concerned about body weight, even when their weight is normal. Excessive concern about weight may cause or lead to such unhealthy behaviors as excessive exercise, self-induced vomiting, and the abuse of laxatives or other medications. These practices may only worsen the concern about weight. If you lose weight suddenly or for unknown reasons, see a physician. Unexplained weight loss may be an early clue to a health problem.