How is a patient's body mass index (BMI) calculated?

The calculation of a patient's body mass index (BMI) is accurately represented by the formula where BMI is determined by dividing the patient's weight in kilograms by their height in meters squared. This approach allows for the assessment of body weight relative to height, which helps in evaluating whether a person falls within a healthy weight range, underweight, overweight, or obese.

Using this formula is beneficial as it standardizes weight and height measurements, making it easier for healthcare professionals to assess and compare an individual’s weight status regardless of differing units of measure. It derives from the understanding that weight should be proportionate to the square of height to reflect body composition accurately.

While other calculations do exist, including variants that use pounds and inches, they involve additional conversion factors or different arrangements of weight and height, which are not the standard form of the BMI calculation most widely recognized and applied in clinical and public health settings. The simplicity of the kilogram and meter system in option A makes it the most straightforward and commonly used method for determining BMI.