# How to identify whether a child is overweight?

Whether a child's "puppy-fat" is still normal or has already become harmful is often difficult to determine. Use of the Body Mass Index (BMI), which is a measure of body fat based on one's height and weight, can help with the assessment. For every age, there is a BMI-group in which a child can be classified as under-weight, normal-weight, over-weight or obese.

The formula for calculating the BMI is:

weight in kg
--------------------------------- = BMI
height in m x height in m

Example: Max is 4 years old, weights 16 kg and is 104 cm tall.

16 kg
-------------------- = 14.8   >>  Max is normal weight because his BMI is below 16.7.
(1.04m x 1.04m)

Table: BMI-threshhold for overweight and obesity

 Boys Girls age overweight obese overweight obese 4 16.7 to 18.3 18.4 and above 16.9 to 19.0 19.1 and above 4.5 16.6 to 18.2 18.3 and above 17.1 to 19.3 19.4 and above 5 16.6 to 18.3 18.4 and above 17.1 to 19.4 19.5 and above 5.5 16.7 to 18.6 18.7 and above 17.3 to 19.8 19.9 and above 6 16.9 to 19.1 19.2 and above 17.5 to 20.3 20.4 and above

Source: Mayer M et al.: Weight and body mass index (BMI): current data for Austrian boys and girls aged 4 to under 19 years. Ann Hum Biol, Early Online: 1–11.