| The Body Mass Index (BMI) is one of the most
common ways of classifying whether people’s
weight is appropriate for their height. Used by
the World Health Organisation, it is a useful
indicator of the health risks associated with being underweight, overweight or obese. |
| BMI is defined as the weight in kilograms divided by the square of the height in metres
(kg/m
2
). |
| For example, an adult who weighs 70kg and whose
height is 1.75m will have a BMI of 22.9. |
| BMI = 70 (kg) / 1.752 (m
2
) = 22.9 |
| The higher the score usually indicates higher levels of body fat. The higher the figure the
more overweight you are. |
|
Underweight |
Healthy Weight |
Overweight |
Very Overweight |
Obese |
| BMI is often used to determine the level of health
risk associated with obesity and is a simple
calculation from standard measurements. |
Although BMI is a widely used standard method to
verify whether a person’s weight is healthy
or not, it is not an absolute accurate calculation, as body compositions can vary between
individuals.
There are a number of factors that might influence whether or not your BMI is a true reflection
of your total body fat. |
| For instance, muscle is denser than fat and takes up less space. Therefore an athlete or
heavily muscled person might weigh more than
a same sized over-weight person, or two
individuals with identical BMI might have widely
different body fat percentages. In this case,
calculating your body-fat percentage
might require the advice of a GP. |
BMI may not be accurate for pregnant or lactating women.
Inaccuracies may also occur in older people, as bones may begin to weigh less. |
| Like any of these types of measures it is
only an indication and other issues such as body
type and shape have a bearing as well.
Remember, BMI is just a guide! |