For most young women, diet and exercise play an important role in maintaining a healthy body weight and conforming to a lean body image. But severe dietary restrictions can be unhealthy if they begin to cause disruptions in your menstrual cycle. Athletic women who train hard are at high risk for menstrual problems when energy demands are not met due to restricted carbohydrate intake.
Carbohydrates and Energy
Carbohydrates are plant-based foods that your body needs for muscle function and biologic work. During high intensity exercise, you use carbohydrates almost exclusively. According to sports nutritionists at Iowa State University Extension, in addition to fueling muscle, your brain and central nervous system rely on carbohydrates for optimal function, and you need carbohydrates in order to burn fat. To meet energy needs, athletes and physically active women need to consume six to 10 grams of carbohydrate per kilogram of body weight daily, making up 50 to 70 percent of your total caloric intake. Yet women often restrict carbohydrates to prevent weight gain.
Energy Imbalances and Menstruation
Brown University's Health Education website describes a condition not uncommon to young active females called amenorrhea. The condition is marked by irregular periods ranging from 60 to 90 days between periods or a total cessation of periods in the absence of pregnancy. According to nutritionist and registered dietician Nancy Clark MS, RD, CSSD, when a young woman's energy intake is inadequate to meet her energy demands, she'll stop menstruating.
Nutrition-Related Amenorrhea
Because carbohydrates are your primary energy fuel, restricting carbohydrate consumption can lead to amenorrhea. A 2003 Johns Hopkins Medical study of the effects of a ketogenic, or low-carb, diet on 45 subjects aged 12 to 19 found a 45 percent incidence of menstrual dysfunction among female participants. An older 1994 study performed by the Department of Obstetrics and Gynecology at St. Luke's-Roosevelt Hospital in New York compared amenorrheic subjects to women with normal periods and identified inadequate nutrition as a significant cause of amenorrhea.
Female Athlete Triad
While absent or irregular periods may not seem important to active young women, the health consequences of restrictive nutrition can be serious. The underlying cause of amenorrhea is a drop in estrogen, the primary female reproductive hormone that also impacts bone density. Amenorrhea can be a red flag for the onset of the female athlete triad, a downward spiral that begins with disordered eating leading to a drop in estrogen, amenorrhea and eventually osteoporosis. The American College of Sports Medicine warns that the Triad can result in fatigue, poor performance and a predisposition to injury and fractures. The ACSM encourages you to seek medical intervention if you experience symptoms of amenorrhea.
References
- Epilepsia: The Ketogenic Diet: Adolescents Can Do It Too: M.A. Mady, et.al., June, 2003
- Athletes Advisor: Sports Nutrition Tips for Women with Amenorrhea
- American College of Sports Medicine: Osteoporosis May Occur Prematurely
- Journal of the Society for Gynecological Investigation: Hypothalamic Amenorrhea and Hidden Nutritional Insults: M.P. Warren, et.al., Jan-Mar, 1994
- Brown University Health Education: Amenorrhea
- Iowa State University: Eat to Compete: Carbohydrates
Member Comments