The BMI (Body Mass Index) is used internationally for checking whether your weight is within the healthy range for your height. Although suitable for most adults, the BMI shouldn't be used for children, pregnant women, the elderly or ill. Other exceptions are weight trainers or athletes with highly developed muscles, who may find their BMI rating places them in the obesity category. This is due to the fact that fat is lighter by volume than muscle mass and the BMI doesn't take into account the difference between fat and muscle. If your BMI is somewhat larger than it should be read the rest of this article for some sensible guidelines to help get your body mass index out of the danger zone.