Understanding BMI in Children


What is BMI?

BMI stands for Body Mass Index. It is a number that can be calculated from a child's weight and height. For most children it is a reliable indicator of body fat. After BMI is measured, it is plotted on a graph to determine a child's BMI percentile. The amount of body fat changes with age and differs between boys and girls. Due to these differences, healthy weight ranges are not provided for children.


How do I measure BMI?

To determine BMI use the following equation:

weight in pounds x 703
height in inches x height in inches

go to www.keepkidshealthy.com for a BMI calculator


What does the BMI percentile mean?

less than 5th percentile underweight
5th percentile to less than 85th percentile healthy weight
85th percentile to less than 95th percentile at risk of overweight
95th percentile or greater overweight

«BMI is used as a screening tool and not a diagnostic tool. An athlete for example may have a high BMI and be classified as “at risk of overweight”. However this person may just be very muscular and not have a lot of body fat.


What are some of the health risks associated with a high BMI?

Heart disease
Hypertension (high blood pressure)
Some cancers
Type 2 diabetes


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