This video is about

This video is about
understanding BMI in adults.

The Body Mass Index
is a simple way to take a look

at whether your weight is healthy
in relation to your height.

Dr Julian Spinks
GP

You take your height in metres,
multiply it by itself

and then divide your weight in kilograms
by that.

In fact, generally it's a lot simpler
to go online

and use a body mass calculator,

or a table
which allows you to look it up.

It's very useful to know your BMI,

because it allows you to see
whether you're underweight,

that's a BMI below 18.5,

or if you're overweight,
one over 25.

Because if you are overweight,
you carry a higher risk of diseases

such as heart disease and stroke
and type 2 diabetes.

Once you know what your BMI is,

you know whether you need to be
losing weight to improve your health.

Being underweight is also not healthy.

So if your Body Mass Index
is below 18.5,

it may mean that you need
to build your weight up.

You've got to do that
in a healthy manner

and it's worthwhile
talking with a doctor to find out how.

There are some circumstances where
Body Mass Index isn't applicable.

If someone is a very athletic type
who has a lot of muscle,

then the Body Mass Index will be
overestimated by the calculation.

Also, women who are pregnant, the
pregnancy will push their weight up

and the BMI will go up with it.

Also we need to take into account
where your weight is.

If you put on a lot of weight
around your middle,

it may be that you're unhealthy,

even though your BMI appears to be
within the normal range.

In people where most of the weight
has gone on round the middle,

there are alternative ways
of looking at healthiness,

one of which is to measure
your waist circumference

or to look at the ratio
between your waist and your hips.

Your doctor will be able
to advise you how to do that.