Parents’ Guide - What Is BMI Score

 

Body Mass Index (BMI) is a number calculated from a child's weight and height that helps determine body fat. BMI does not measure body fat directly, but research has shown that BMI is a reliable indicator. The BMI score is used to help adults determine their weight status. However, BMI-for-age is used for children and teens to take into account a child’s growth. The number is given in percentile.

 

What Is A BMI-For-Age Percentile?  

Children are growing and children of the same age can really vary in height. A child’s height needs to be taken into consideration because a taller child may weigh more than a shorter child. Growth charts have been created representing children of different gender, heights, ages and their correlating BMI scores. From these charts, your child’s BMI score is then plotted to see how their score compares with other children of the same age and sex. Depending on where their score fell, a percentile ranking is determined. The growth charts show the weight status categories used with children and teens (underweight, healthy weight, overweight, and obese).

BMI-for-age weight status categories and the corresponding percentiles are shown in the following table.

Weight Status Category	Percentile Range
Underweight	Less than the 5%
Healthy weight	5% to less than the 84%
At risk of overweight	85% to 94%
Overweight	Equal to or greater than the 95%