What is childhood obesity? BMI is generally used to determine obesity in children and adults. However specific categories as classified by WHO for adults are not used for children. Instead BMI for age is calculated which is gender and age specific. The classification is done on the basis of age and sex specific percentiles of BMI. The reason being that the body composition of a child is continuously changing and there also exists a difference in the growth patterns of boys and girls. Therefore it would not be accurate to compare the two genders with each other. (1)
