Body Mass Index (BMI)

General
This is general advice for adults only. It does not apply to children, pregnant or breast feeding women. Also your BMI may not be accurate if you are a weight-trainer or an athlete, if you are over the age of 60 or you have a long-term health condition.

Body Mass Index (BMI) is a number calculated from a person’s weight and height. BMI is a reliable indicator of body fatness for people.

Calculation
The healthy weight range is based on a measurement known as the body mass index (BMI). This can be calculated if you know your weight and your height.

To work out your BMI, simply follow these three steps:
1. Work out your height in metres and multiply the figure by itself.
2. Measure your weight in kilograms
3. Divide the weight by the height squared (i.e. the answer to Q1). For example, you might be 1.6m (5ft 3in) tall and weigh 65kg (10st). The calculation would then be:

Height  = 1.6 x 1.6 = 2.56.
Weight  = 65
BMI would be 65 divided by 2.56 = 25.39.

Try if for yourself!

If your BMI is below 18.5:
This normally indicates a lean BMI, which indicates low body fat. This can be helpful in some circumstances (if you are an athlete for instance). However, a low BMI can also indicate that your weight may be too low which could in some situations lower your immunity to disease. If your BMI and body weight are low, you should consider gaining increased muscle mass through a healthy diet and exercise program.

If your BMI is between 18.5 and 24.9:
This range indicates a healthy level of body fat. A BMI percentage in this range is associated with low incidences of serious illness.

If your BMI is between 25 and 29.9:
A person with a BMI in this range is generally considered to be overweight, and having an increased risk of associated diseases. If you are in this range you may want to find ways of lowering your weight. A healthy diet and the starting of an exercise program might be helpful.

If your BMI is between 30 and 39:
In this we are now inside the obesity range. It is necessary to change your lifestyle. You will need to change to a healthy diet and take regular exercise.  If your waist size is greater than or equal to 40 in. (men) or 35 in. (women) then there is a very high associated risk of disease.

If your BMI is over 40:
This indicates an individual suffering from extreme obesity. It is a very unhealthy condition. The excess body fat puts the individual at risk of heart disease, high blood pressure, diabetes and certain types of cancers. It is definitely time to change to a healthy diet and a fitness program.