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Preventing Relative Energy Deficiency in Young Athletes

Contributors: Monique Ryan, MS, RD, CSSD, LDN

Reviewers: Academy Nutrition Information Services Team

Published: July 20, 2018

Reviewed: January 19, 2023

Girls soccer team - Preventing RED-S in Young Female Athletes
Barry Austin/DigitalVision/Thinkstock

It can start innocently enough. A young athlete pushes themself harder than usual, training intensely to gain a competitive edge. While this increased output naturally requires consuming more calories to meet the total demands of training and recovery — not to mention growth and development — their diet does not change. The result is a condition known as "relative energy deficiency in sport," or RED-S.

Coined by an expert panel convened by the International Olympic Committee, RED-S is a more comprehensive term that builds off the condition known as the "female athlete triad" to describe an energy deficiency gap that results when energy intake is insufficient to support activities of daily living, growth, health and functioning. This syndrome affects bone health, metabolic rate, immune system function, protein synthesis, cardiovascular health and psychological health, as well as menstrual function in females. Research suggests that RED-S is more common among females, although it also affects male athletes.

RED-S can develop when there is pressure to change eating habits, especially in sports with an emphasis on appearance, low body weight and endurance.

Adolescents are exposed to dieting and other nutrition messages perceived as "healthy" that often are inappropriately applied to those who are growing, developing and training. A desire to "eat healthy" or lose weight in hopes of improving athletic performance can increase susceptibility to willful food restriction and rigid dieting.

It may be difficult for younger individuals to understand how their energy needs translate into daily food choices. An eating disorder does not have to precede the development of RED-S, though some level of psychological factors can be present before, as well as after the syndrome develops. Regardless of the starting point, serious short-term and long-term health consequences can occur in young athletes who develop RED-S.

The Effects of RED-S

First, bone health is a major concern as adolescents build up to 90% of their bone mass by age 18. When preteens and teenagers restrict their eating, body systems important to bone growth may shut down. Restricted diets also can be low in calcium and vitamin D, which contributes to poor bone formation. If RED-S continues without being addressed, poor bone growth can lead to stress fractures and even early osteoporosis, in which bones become fragile and more likely to break.

Another concern is reproductive development for females. Important markers of insufficient energy and resulting low estrogen levels include delayed menstruation and irregular or missed cycles.

Other potential effects of RED-S include increased risk of injury and decreased endurance and muscle strength. And, it can reduce response to training, decrease coordination, impair judgment, increase risk of infections and illness, and increase irritability and depression — results that no athlete wants to have happen.

Preventing and Treating RED-S

Parents can play a significant role in preventing RED-S. First, educate your children on the energy demands of their training and its relationship with proper nutrition and bone health, as well as the risk of injury. Second, keep an eye out for weight loss, changes in menstruation and changes in mood.

Finally, create a supportive environment in which young athletes can consume three meals and one to three snacks per day. Even missing one meal on a regular basis can result in an energy deficit. Make sure your child has a regular breakfast and packs or eats a full lunch at school. Many young athletes train after school, and an easily digested snack prior to practice can provide energy for training. Good snack choices include an energy bar, cereal, crackers, banana, fruit and fruit juice, pretzels, and peanut butter and jelly sandwiches.

The good news is correcting RED-S does not mean a sacrifice in athletic performance. In fact, it should result in an improvement in athletic performance.


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