Background:The body mass index (BMI) was described back in 1832 by Adolphe
Quetelet and then was validated by Ancel Keys in 1972. BMI is the ratio of body
weight expressed in kilograms, divided by height expressed in metres squared.

Methods:The aim of this review was to discuss the different criteria used
for the assessment of BMI in adults and children, and to provide practitioners
and researchers with the tools and information they need based on the
established international BMI norms, in order to conduct an appropriate weight
assessment.

Results:Although the BMI score is calculated in the same way for children
and adolescents as the one for adults, the criteria used for weight assessment
are different, due to the fact that the BMI in children varies significantly
with age. The BMI score in children and adolescents is compared against
reference charts for children of the same age and gender, andit is therebytransformed
into a percentile score. The assessment of each individual as obese,
overweight, normal, underweight, severe thinness is then made based on this
percentile score.

Discussion:Even though the BMI is the most popular anthropometric index, its
main drawback is that it does not distinguish between fat and muscle tissues,
and, therefore, the BMI might be an inappropriate method for assessing body
weight in some people.