Health and Human Development

New online tool predicts risk of energy deficiency in young, exercising women

Energy deficiency is a common problem among physically active women and can result in bone and reproductive health problems

Energy deficiency is a common problem for athletes and other women who are physically active. A new online questionnaire, developed by researchers in the Penn State Department of Kinesiology, can identify women who may be at risk for energy deficiency. Credit: franckreporter/Getty Images. All Rights Reserved.

UNIVERSITY PARK, Pa. — Many female athletes and physically active women fail to consume enough energy to meet their bodies’ needs, jeopardizing their reproductive and bone health and athletic performance, according to prior studies by researchers at Penn State and elsewhere. Measuring energy deficiency can be a barrier to understanding the problem, however, because it requires extensive laboratory testing or invasive blood collection. 

To evaluate the risk for energy deficiency more easily, a team of researchers in the Penn State Department of Kinesiology developed and validated a brief, online questionnaire. It can be used by athletic directors, doctors, coaches, dietitians, athletes or any interested person to determine whether an active, young adult woman may be at risk for energy deficiency. 

A study describing the development and validation of the questionnaire, called the Female Energy Deficiency Questionnaire (FED-Q), was recently published in Medicine & Science in Sports & Exercise

“The FED-Q provides an objective measure of a woman’s risk for energy deficiency,” said lead author Ana Carla Chierighini Salamunes, who successfully defended her dissertation in kinesiology at Penn State in May. “FED-Q cannot diagnose energy deficiency — that requires medical evaluation. It can, however, screen women quickly and for free so that people know whether to seek further evaluation and possibly treatment.”

Understanding energy deficiency

For 20 years, Mary Jane De Souza, distinguished professor of kinesiology and physiology, and Nancy Williams, professor of kinesiology and physiology, have led the Women’s Health & Exercise Lab in the Penn State Department of Kinesiology, studying the prevention and consequences of energy deficiency in athletes.

The FED-Q was developed using data from 202 women who participated in seven different studies conducted in the Women’s Health & Exercise Lab over the last two decades. All participants had completed biological assessments of energy deficiency, height and weight. They also responded to multiple questionnaires that assessed eating behaviors, body dissatisfaction and more.

“There is no single biological measure that can be used to detect energy deficiency,” said De Souza, who served as Salamunes’s doctoral adviser. “This complicates the creation of any questionnaire to measure the problem. Over years of study and experimentation, however, researchers in the field have largely come to agree that serum total triiodothyronine, or T3, is a reliable proxy for energy deficiency.

T3 is a chemical found in the blood serum that dictates how fast or slow a person’s metabolism operates. When T3 is low, metabolism slows. When a woman does not consume enough nutrients to meet her needs, her body reduces T3 to conserve energy and slow her metabolism. T3 is lower whether people have energy deficiency over a short or long period of time, so it is the most reliable measure of the problem, according to the researchers.

Building the FED-Q

To construct the FED-Q, the researchers selected all the measurements that correlated with energy deficiency based on their prior research, including body mass index (BMI), health history, menstrual status, body dissatisfaction and measures of self-imposed restrictions on eating. Then, they compared the responses of 152 of the study participants to the women’s T3 levels.

If the measurements accurately predicted low T3, the researchers retained them as candidate items for the FED-Q. After multiple rounds of statistical analyses to reduce the number of questions needed, the items selected were compared to data from the 50 women in the study who were not used in the initial selection of the items. In this way, the researchers were able to validate that the FED-Q can predict — with about 82% accuracy — who is energy deficient.

“This is not a diagnostic tool, and — like any screening tool — it is not 100% accurate,” Salamunes said. “But it is an easy tool with good sensitivity for women between ages 18 and 35 who want to know whether they might be at risk.”

The published version of the FED-Q requires measurements of height, weight and number of menstrual cycles over the last six months. After supplying those measurements, participants answer nine multiple-choice questions, and the website calculates their risk for energy deficiency. The process takes just a few minutes.

Providing immediate feedback for women with energy deficiency

“This was a very exciting project because the FED-Q is out in the world, helping people right now,” Salamunes said. “Research is a slow process. It takes a long time to build evidence-based knowledge and tools. So, it is gratifying that this work has matured to the point that any women can access the FED-Q online for free and learn about their risk for energy deficiency.”

The researchers agreed that completing the FED-Q is easy, but what really matters is how women use the information the questionnaire provides.

“If someone is at risk of energy deficiency, they need appropriate guidance on how to reverse that problem,” Salamunes said. “First, talk to the athlete and let her know how important it is to address energy deficiency. Then, refer her to a dietician to ascertain whether she is getting enough energy. If this might be a long-term problem, refer the athlete to a physician who can investigate her bone health and menstrual health. Psychologists may be helpful as well, since the energy deficiency is frequently associated with body image issues in female athletes. Consuming enough energy will support peak athletic performance — but much more importantly — it will set the athlete on the path to a long, active, healthy life.”

Last Updated May 30, 2025

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