Weight and height measurements:

• The weight of the child should be taken after voiding and before meal. The child should be wearing only light clothing, he should stand relaxed and still and look straight ahead.
• Height should be measured accurately. Clothing should be minimal when measuring height so that the posture of the child can clearly be seen. Shoes and socks should not be worn. The child should stand with the back and head straight

BMI calculation and interpretation:

• BMI is the weight of the individual divided by the square of his height (BMI = Wt (kg)/ Ht(m)2)
• BMI correlates well with body fat in a population which means that in general, the higher the BMI, the higher the body fat content.

In children, the assessment of weight status is much more complex. This is because children are growing and the growth patterns (and hence the BMI) of children differs according to their age.

The pattern of growth is dependent on the sex of the child since the growth pattern for boys is very different from the growth pattern for girls.

For children, BMI is determined — based on carefully measured height and weight — and then graphs or growth charts are used to find each child’s BMI percentile-for-age by plotting the BMI value versus age on a growth chart for that child’s sex.

To use a BMI chart, you must know the birth date of the child, so that you can calculate the age of the child (in months) on the date that his or her height and weight were measured.

• Birth to 36 months (5th-95th percentile)
• Boys Length for age and Weight for age
• Girls Length for age and Weight for age
• Children 2 to 20 years (5th-95th percentile)
• Boys BMI for age
• Girls BMI for age
• Boys Stature for age and Weight for age
• Girls Stature for age and Weight for age

• Adolescents who are found to be < 5th percentile of weight for height or BMI for age and gender are classified as underweight and should be referred to a primary healthcare provider.
• Adolescents with a BMI ≥ 85th percentile but < 95th percentile are classified as at-risk for overweight. They should be asked for a full medical evaluation.
• Teenagers with a BMI ≥ 95th percentile are classified as overweight and should be asked for a complete medical evaluation to determine potential obesity-related complications.