What is adolescent obesity?

Teens between the ages of 12 - 19 who are more than 10 percent over the ideal weight for their height and age are considered obese. Obesity in adolescents has drastically increased over the last 30 years. According to the Centers for Disease Control and Prevention, one in six teens are obese in the United States. Hispanics, and non-Hispanic blacks are more likely to become obese during adolescence than Caucasians.

Because habits developed in adolescence typically transfer to adulthood, it is important to treat the condition early with healthy eating and physical activity.

If not treated early, obesity can lead to serious conditions such as heart disease, diabetes, cancer and musculoskeletal problems. The estimated cost to treat obese adolescents is more than $14 billion annually in the United States.

Common related conditions
Obesity Childhood Obesity

Causes of adolescent obesity

Adolescent obesity is most frequently caused by a combination of genetic factors, unhealthy eating and lack of physical activity. In rare cases, a medical condition or medications can cause a person to gain an excessive amount of weight.

Eating patterns and activity level are preventable causes that can be managed.

Risk factors of adolescent obesity

There are a variety of factors that can increase a teen’s likelihood of developing adolescent obesity including:

  • Genetics — you are at higher risk of becoming obese if you have a family history of obesity
  • Eating unhealthy foods — eating unhealthy foods such as foods high in saturated fats and sugary drinks on a regular basis can put you at higher risk of developing obesity
  • Leading sedative lifestyle — people who are not active on a regular basis are more likely to become obese
  • Medical conditions — certain medical conditions can disrupt the normal functions of hormones and put you at higher risk for becoming obese

Symptoms of adolescent obesity

If your child has a body mass index (BMI) over the 95th percentile compared to teens the same age and sex, he or she is likely obese. If your teen is obese, he or she may experience symptoms related to obesity conditions such as high cholesterol, high blood pressure, and sleep apnea.

Diagnosis of adolescent obesity

Body mass index (BMI) is the primary way to diagnose adolescent obesity. Your Mercy Health pediatrician or family medicine doctor will use a growth chart to determine your teen’s BMI percentile. The percentile will compare your teen with other teens of the same age and sex. If a teen is in the 90th percentile, he or she has a BMI higher than 90 percent of teens the same age.

Weight categories include:

  • Overweight — between 85th and 94th percent
  • Obese — 95th percent or above
  • Extremely obese — more than 1.2 times the 95th percent

In some cases, your teen may have a BMI over 30 but is very athletic and muscular, which the BMI calculator cannot take into consideration. Your teen’s doctor will evaluate your child individually if he or she may fall into this category.

Treatment for adolescent obesity

Treatment for adolescent obesity starts with modifying unhealthy lifestyle habits such as sedative activity level and unhealthy eating habits. If modifying behaviors alone is not effective, medication or bariatric surgery may be necessary. Your Mercy Health doctor will work with you to set goals specific to your child’s case.

Lifestyle modifications

As adolescents age, they become more likely to develop obesity-related health issues that need to get under control. In many cases, once the adolescent gets to a healthy weight, the medical conditions and symptoms can be reversed. Lifestyle modifications include:

Dietary changes
We recommend limiting sugary foods and drinks, avoiding saturated fats and fried foods and eating a lot of fruits and vegetables. Learn more about nutritional guidelines to lose weight.

Activity level
Adolescents should get at least an hour of activity each day. Anything that gets your heart rate up — from walking to school, organized sports, hiking, biking, karate or swimming can help increase metabolism to aid in weight loss.

It is never too late to start healthy habits.


In teens who do not respond to lifestyle changes, medications may help teens lose weight. Learn more about weight loss with medications.


When all other less invasive options have failed, surgery may be an option to treat severe obesity. This is only an option if the risks of being obese outweigh the risks associated with surgery. The most common surgical treatment for obesity is gastric bypass surgery.

Find an adolescent obesity specialist nearby

Mercy Health locations that can treat you