Your BMI gives and indication of your health risks.
BMI between 18 and 25 is regarded as "Normal",
Between 25 and 30 is classed as "Overweight"
Between 30 and 40 is in the "Obese" range.
If you have a BMI over 40 you are classed as "Morbidly Obese."
Not only can obesity affect life expectancy it can be responsible for conditions such as:cardiovascular disease, diabetes Type II, stroke, cancer, joint problems such as osteoarthritis and high blood pressure.