So, what exactly is BMI?

Simply put, your BMI is a ratio of your weight compared to
your height. It really is that simple. In fact, it is that simplicity that
means that BMI isn’t always a 100% reliable way to judge if your body shape is
putting you at risk of weight-related health problems.

Now, that’s not to say that you should ignore the BMI value
you get – a healthy adult should be looking at having a BMI value of between
18.5 and 25 and if you do have a value of above 35 in particular then you are
definitely at risk of weight-related health problems, regardless of any other
factor.

That said, for the 25-35 BMI range there are a few risk
categories which may cause over or under-estimation, which include:

• Age – BMI is meant to be used for adults,
  so for children it often requires a more specialised calculation as…