Final answer:
BMI in children is used to assess body fat but differs from adult measures due to growth, leading to adaptations like comparing to reference values for age. Unlike adults, obesity in children is diagnosed by a BMI percentile rather than just raw numbers. BMI is still debated as a measure due to its limitations.
Step-by-step explanation:
The subject of the question is BMI in children and how it is approximately normally distributed with a specific mean and standard deviation. BMI, or Body Mass Index, is a measure of body fat based on height and weight that applies to children and adults. For children and adolescents, BMI is used differently compared to adults. It is not simply a measure but compared to reference values to determine categories such as normal weight, overweight, or obese. BMI is also less reliable during growth periods due to varying rates of fat, muscle, and bone development.
For instance, a child's BMI greater than the 95th percentile compared to peers of the same age is considered obese. However, due to growth and varying rates of development, a new method has been introduced for calculating BMI in children, dividing the weight in kilograms by the height in meters cubed, although it is not yet widely adopted.
The World Health Organization (WHO) tracks child development by comparing weights of children of the same height and gender. For instance, the weights were normally distributed with a mean of 10.2 kg and standard deviation of 0.8 kg for all 80 cm girls in 2009, and z-scores could be calculated for different weights to understand their position within this distribution.