Causes of a Teen Boy's Lack of Energy

Lack of energy in teen boys can be due to a number of reasons, including as a symptom of an underlying, much larger problem such as depression or an eating disorder. Regulate your teen boy's sleep habits and ensure he is eating a nutritious diet for optimal energy. Talk to him about school and his friends as problems in either of these areas can lead to stress and therefore low energy levels.

Eating Disorder

Lack of energy could be a sign of an eating disorder, such as anorexia nervosa. Anorexia is when a person purposefully starves in order to lose weight, and it is the most common eating disorder among teens, according to Troubled Teen 101 1. In addition to lack of energy, other symptoms of anorexia include:

  • denial that he is underweight
  • losing weight although already underweight
  • obsession with what he eats
  • an obsession with looking athletic
  • barely eating although he says he is never hungry


Fatigue or lack of energy could be a symptom of depression in a teen boy, according to Help Guide 2. While occasionally acting out or being in a bad mood is normal, depression is defined as overwhelming sadness, despair or anger on a regular basis, which cause severe damage to a teen boy's personality. It can also result in problems at school or at home, drug abuse and even suicide.

Lack of Sleep

A teen boy may feel tired all the time because he is simply overbooked. Teens with jobs often get less sleep and have lower grades than teen boys without jobs, according to "Back to School: Healthy Sleep Habits" from Good Morning America 3. Adolescents require eight and a half to nine and a half hours of sleep per night, and inconsistent bed times can result in sleep and academic problems. Extracurricular activities, social demands, homework and early morning classes can also result in lack of sleep and therefore low energy, according to Mayo Clinic.

Other Causes

Other, less frequent potential causes of lack of energy in your teen boy include sleep apnea, or temporary cessation of breath during sleep; drug and alcohol abuse; obesity; Epstein-Barr virus; chronic fatigue syndrome; lupus; bipolar disorder; fatal familial insomnia; and traumatic brain injury. Stress and anxiety due to schoolwork, social pressures, activity participation and part time jobs can also result in a lack of energy. Poor diet is another cause--ensure your teen is eating enough "good carbs" such as fruit, vegetables and whole grains, which will give him energy. Whole grains are also a good source of protein, which is needed for energy and concentration.