Children's Hospital Colorado

Severe Obesity in Children

What is severe obesity?

Obesity is diagnosed based on how a child's body mass index (BMI) relates to the normal range for their age and gender. BMI is calculated using your child's weight and height. To be diagnosed with severe obesity, a child's BMI must be at or above the 99th percentile for their age and gender.

To compare, overweight children have a BMI in the 85th to 95th percentile, and obese children have a BMI in the 95th to 98.9th percentiles.

You can determine your child's BMI using the CDC BMI calculator.

What causes severe obesity?

Severe obesity results from lack of energy balance. This means that the calories your child takes in through food and drinks are greater than the calories they burn at rest and during exercise.

Most patients with severe obesity do not have a known medical cause for their obesity. However, there are medical conditions that can make children more likely to gain weight. These include very rare genetic conditions and conditions that affect a part of the brain called the hypothalamus.

Who is at risk for severe obesity?

Severe obesity can affect children of all ages, races and ethnicities, and it affects boys and girls equally. It is more common among minorities, children with a family history of obesity and children born to mothers who are obese during pregnancy. Some minorities at risk of severe obesity include African Americans and Hispanics.

The Connection Journey
A journey to wellness

Our pediatric experts can explain a lot about bariatric surgery as a treatment option for severe obesity. One thing they can't tell them: how they will feel throughout the process. Listen as Mona tells Jessika about the increased energy level and improved health she's experienced after bariatric surgery.

Watch their stories

Get to know our pediatric experts.