(CENTER FOR DISEASE CONTROL) July 17, 2018 — In the United States, the percentage of children and adolescents affected by obesity has more than tripled since the 1970s.¹  Data from 2015-2016 show that nearly 1 in 5 school age children and young people (6 to 19 years) in the United States has obesity.²

Obesity is defined as having excess body fat.³ Body mass index (BMI) is a widely used screening tool for measuring obesity. BMI is a person’s weight in kilograms divided by the square of a person’s height in meters. Scientists have found that BMI is moderately related to direct measures of body fatness. Measuring height and weight is easier and less expensive than other methods for assessing weight status.

CDC recommends that health professionals use BMI percentile when measuring the bodies of children and young people aged 2 to 20 years. BMI percentile takes into account that young people are still growing and are growing at different rates depending on their age and sex. Health professionals use growth charts to determine whether a young person’s weight falls into a healthy range for his or her height, age, and sex.

• CDC defines overweight in children and young people as a BMI at or above the 85th percentile and less than the 95th percentile for young people of the same age and sex.
• CDC defines obesity in children and young people as BMI at or above the 95th percentile for young people of the same age and sex.

For more information about BMI measurement for children and adolescents: About Child & Teen BMI

For more information about BMI measurement in school settings: Body Mass Index (BMI) Measurement in Schools

https://www.cdc.gov/healthyschools/obesity/facts.htm