The body mass index (BMI) is a method of comparing a person's height to his weight. It was introduced in 1972 and is a convenient method of assessing a person's weight. The BMI may be used on adults as well as children, although the specific methods differ.
Calculation
The BMI may be calculated by dividing the subject's weight in kilograms by the square of the subject's height in meters. A BMI value that uses other units of measure will usually need to be converted to kilograms and meters, as these are the units that most BMI charts use.
Adults
The BMI will indicate the weight classification in which the subject belongs. These classifications include severely underweight, underweight, normal, overweight and obese. The standard BMI chart for adults doesn't take age or gender into account, although some BMI charts do.
Children
The BMI for children between the ages of 2 and 20 must take gender and age into account in order to be meaningful. The correct BMI chart for the child's gender must be consulted in order to determine the child's BMI percentile score. A BMI percentile of 5 percent is considered to be underweight for a child. A BMI percentile in the range of 85 to 95 indicates the child is overweight and a BMI percentile greater than 95 indicates the child is obese.
Usage
The BMI can provide an inaccurate weight classification for someone who doesn't have an average frame. It's also designed for people who are generally sedentary and will tend to place physically active people into a higher weight classification. This is due to the fact that a person with greater muscular development tends to have a higher ideal weight.
BMI Prime
The BMI Prime is the ratio of a person's BMI to the minimum BMI that qualifies as overweight for that person. This value allows for an easy assessment of a person's weight since someone who is at her healthy weight limit will have a BMI Prime of 1. A person who is in the healthy weight range will have a BMI Prime value 0.74 and 0.99.
Member Comments