Participation in sports by girls and young women has soared in recent decades — by 560 percent among high school students since 1972, and 990 percent among college students, according to the Women's Sports Foundation. Highly committed young female athletes now run track and play soccer, basketball, water polo and other demanding sports that require strong bodies.
But many girls aren't eating enough to satisfy the physical demands of those sports, scientists say, and that's putting them at risk for health problems that can last a lifetime.
These athletes are essentially malnourished. The danger they face is called female athlete triad syndrome because it typically includes three symptoms: irregular menstrual cycles, low energy and low bone density.
Doctors once looked for this constellation of symptoms only among "anorexic, very skinny" young women, says orthopedic surgeon Dr. Elizabeth Matzkin, chief of Women's Sports Medicine at Brigham and Women's Hospital in Boston.
But experience has since shown, she says, that "these athletes can come in any shape, form or weight. It's not just that typical ballerina physique that we're looking out for anymore."
Unfortunately, she says, many primary care doctors still don't recognize the syndrome and most of these athletes don't know they're at risk. Take Regan Detweiler, a University of Michigan sophomore. She ran track and cross country in high school, and used to train all year long — running, on average, 35 to 40 miles a week, she says.
Detweiler also adhered to a rigid, low-carb diet — she says she had a "very unhealthy relationship" with carbohydrates.
Breakfast for her in those days was coffee and a cup of yogurt. Lunch was a peanut butter sandwich, minus the crust.
"I was eating as little of that peanut butter sandwich as I could possibly eat," she says, "while still saying I had a sandwich for lunch." Dinner was a small serving of meat and vegetables.
Detweiler says she was hungry pretty much all the time, and often felt tired in the middle of the day. She menstruated only once every six months or so.
Then, during her sophomore year in high school, Detweiler suffered a stress fracture in her right shin. She took a month off running and wore a protective boot. But during her junior year, she suffered another stress fracture — this time in her left shin. Suspecting weakness in the bone, doctors ordered a density scan.
The results were worrisome. Detweiler says the doctors told her she was on the "very lowest end of having a normal bone density." The diagnosis: female athlete triad syndrome.
Matzkin says anytime a young female athlete comes to her office with shin splits or fractures, she now asks about nutrition and menstruation.
"We may be able to identify the root cause of bone mineral density problems," she says, and patients can be helped early to chart a new course in eating.
It's not just about eating enough, Matzkin says. It's also about eating the right things — like fruits, vegetables, protein and foods rich in calcium and vitamin D. It's critical to build bone when you can, she says, because there's literally a countdown to how long women have to build strong bones.
"We can only really build it up to about age 25," she says. After that, because of hormonal changes, women in particular lose bone density bit by bit every year.
"If you can start at a higher level," she says, "then you're going to do better."
Young athletes like Detweiler, who have already lost bone density, can rebuild some bone, Matzkin says. But "they'll never get back to where they might have been."
Today, Detweiler is 19 years old and eats a healthy diet. She credits Jessica Buschmann, a registered dietitian at Nationwide Children's Hospital in Columbus, Ohio, for helping her achieve that.
Buschmann says many of the athletes referred to her train for hours a day, every day. As a result, she says, it's not uncommon for these young athletes to need as much as 3,500 calories a day — which can seem scarily high to a teenage girl worried about body image.
And that, Buschmann says, is her challenge: to convince these girls that eating too few calories puts the body at risk. She tells them she'll say the word "calorie" only once and then switch to other words like "energy" or "fuel."
"That's truly what it is," she says — energy for your muscles and brain to make sure you're physically and mentally strong enough, and have enough stamina to optimize workouts and training.
Detweiler embraced Buschmann's diet plan of increased calories: three solid meals a day plus three snacks. She still enjoys peanut butter sandwiches for lunch, she says — but now she eats the bread crusts, too.
She soon started menstruating regularly. Her latest bone density scan also shows improvement.
Best of all, Detweiler says, after starting on Buschmann's regimen, she started feeling better than ever — and had her most successful track season ever, too.
STEVE INSKEEP, HOST:
Renee Montagne is back at NPR West. Renee, welcome back.
RENEE MONTAGNE, HOST:
Thank you, Steve. I'm all rested up and here to tell you about an evolving health problem for girls. It's a subject of today's health segment. Girls can play demanding sports in a way that past generations never could. The trouble comes when girls embrace sports like soccer, basketball or track which consume lots of energy, but they don't eat enough. NPR's Patti Neighmond reports.
PATTI NEIGHMOND, BYLINE: It's called female athlete triad syndrome. Symptoms include irregular menstrual cycles, low energy and low bone density. Orthopedic surgeon Elizabeth Matzkin with Brigham and Women's Hospital in Boston says girls who get it are essentially malnourished.
ELIZABETH MATZKIN: We used to think that it had to be that anorexic, bulimic, very skinny female that was going to have these triad symptoms, but we clearly know now that these athletes can come in any shape, form - any weight. It's not that typical ballerina physique that we're looking out for anymore.
NEIGHMOND: She says doctors often don't recognize the problem in their seemingly healthy, young, active patients, and athletes themselves often don't know they're at risk.
JESSICA BUSCHMANN: I'm so happy you're home from Michigan. How was your first year?
REGAN DETWEILER: My first year was great, it was a little crazy.
NEIGHMOND: 19-year-old Regan Detweiler meets with dietitian Jessica Buschmann at Nationwide Children's Hospital in Columbus, OH. Regan first came here about two years ago during her junior year in high school. She was a top athlete in track and cross-country, training year-round and running every day. She also adhered to a rigid, low-carb diet.
DETWEILER: I had a very, very unhealthy relationship with carbs at the time.
NEIGHMOND: Breakfast was coffee and yogurt. At lunch, Regan indulged in a sandwich, but....
DETWEILER: I was not eating the crust. I was eating as little of that peanut butter sandwich as I could possibly eat while still saying that I had a sandwich for lunch.
NEIGHMOND: Regan was hungry most of the day. She had her period only once every six months. Then, she had two stress fractures, and doctors ordered a bone density scan.
DETWEILER: I was on the very, very, very lowest end of having a normal bone density.
NEIGHMOND: Surgeon Matzkin says that's worrisome because there's literally a count-down to how many years women have to build strong bones.
MATZKIN: We can really only build it up till about the age of 25.
NEIGHMOND: After that, women in particular because of female hormones lose bone density bit-by-bit every year.
MATZKIN: If you can start at a higher level, then you're going to do better off than those of us who haven't maximized our bone density.
NEIGHMOND: Young athletes who change their diet can rebuild bone, but Matzkin says they'll never get back to where they might've been had they not lost it in the first place.
BUSCHMANN: I have to ask, of course, how is the food?
DETWEILER: The food was good.
NEIGHMOND: Dietitian Buschmann says some patients require as many as 3,500 calories a day, which can be a scary number for many girls worried about body image. So Buschmann is careful choosing her words when she counsels her patients.
BUSCHMANN: You need X number of calories in a day, but from now on, I'm going to say energy or fuel because that's truly what it is. It's energy for your muscles - is fuel for your muscles, as well your brain to make sure that you're physically and mentally strong enough and have enough stamina to optimize your workouts and training plan.
NEIGHMOND: Regan embraced Buschmann's diet plan - three solid meals a day, plus three snacks. She gained a little weight, but not much. Mostly, she says, she just felt good.
DETWEILER: I had actually the most successful season my senior year cross-country season.
NEIGHMOND: As for those lunchtime peanut butter sandwiches, Regan kept eating them, but added the crust.
DETWEILER: Which was great (laughter).
NEIGHMOND: Today at 19 and a sophomore in college, Regan eats a healthy diet. Surgeon Matzkin says a diet filled with fruits, vegetables, protein, calcium and vitamin D is what it takes for young female athletes to build crucial bone. Patti Neighmond, NPR News. Transcript provided by NPR, Copyright NPR.