What questions should I be asking my child's physician?

What is BMI?

Body Mass Index or BMI, is a one way to determine a child's risk for overweight or obesity. BMI is a calculation that uses height, weight, age and sex to determine how a child is growing.

The BMI formula helps determine whether a child's weight is in proportion to his or her height. To make this determination, children are classified in a BMI percentile – an indication of how a child's measurements compare to others of the same age and gender:

  • a child whose BMI is at the 50th percentile is close to the average of the population.
  • a child above the 95th percentile is considered obese because 95 percent of the population weighs less than he or she does.
  • a child below the 5th percentile is considered underweight because 95 percent of the population weighs more

According to the Pennsylvania Department of Health, when it comes to a child's weight, BMI is not the whole story. A child who is very muscular, like an athlete, may have a higher weight and BMI but not have a lot of body fat. Two people with the same BMI may have different body fat levels.

Each year, Pennsylvania requires schools to report BMI in the same way they report vision and hearing screenings. To better understand a child's BMI percentile, it is important to share the information with the child's health care provider.

Visit the Department of Health's website to calculate your child's BMI today.