Focusing too much on shedding weight to improve performance on the field or court can have major health consequences for female athletes.

Some girls—especially those who participate in sports that prize a lean body, such as swimming, cross country running or ballet—can develop a disorder called the female athlete triad. Also known as relative energy deficiency in sports, the female athlete triad consists of disordered eating, irregular or skipped periods, and reduced bone density, which can lead to fractures.

The conditions that make up the female athlete triad are related, but an athlete doesn’t need to have all three to have a problem.

“These conditions occur on a spectrum,” says Terra Blatnik, MD, a Washington University pediatric sports medicine specialist at St. Louis Children’s Hospital. “To have the full female athlete triad, a patient needs to have all three conditions, but many athletes exhibit only some of the characteristics. That’s still something to be concerned about.”

Don’t be misled by the name—certain parts of the female athlete triad can also affect males.

Spotting the Signs and Seeking Help

If your child seems overly concerned with her weight, experiences rapid weight loss, stops eating entire food groups, such as carbohydrates or fats, or experiences irregular periods, female athlete triad could be the cause. Don’t wait to voice concerns to your pediatrician, who may refer your child to other providers.

“In the short term, sports performance can suffer if a child is burning more calories than she’s taking in,” says Sarah Garwood, MD, a Washington University adolescent medicine physician at St. Louis Children’s Hospital. “Over the long term, the most concerning impact on health is the potential for osteoporosis and fractures.”

Treatment for the female athlete triad depends on which conditions are affecting an athlete—and it’s often collaborative. If, for example, disordered eating and poor nutrition are the primary concerns, your pediatrician may work with a dietitian to create a healthy eating plan for your child. Your pediatrician may also refer your child to a pediatric mental health professional to explore the roots of disordered eating.

Learn more about injury prevention programs by the Young Athlete Center at