How is Body Mass Index (BMI) calculated?

Body Mass Index (BMI) is calculated using a formula that takes both weight and height into account to assess whether an individual has a healthy body weight for their height. The correct calculation involves dividing the weight in pounds by the square of the height in inches and then multiplying the result by 703 to adjust for units.

The formula provided in the correct answer represents this process accurately by including both the multiplication of weight by 704.5 and dividing by height squared, which ensures the value is calculated appropriately for a standard interpretation of BMI. It is crucial to use the weight in pounds and height in inches to maintain consistency within the formula's context.

This method of calculation enables health professionals and researchers to categorize individuals into different weight categories (underweight, normal weight, overweight, and obese) based on the resultant BMI value. Such categorizations help in assessing health risks related to body weight.

In contrast, the other options either omit essential components of the formula or incorrectly structure the relationship between weight and height, leading to inaccuracies in calculating BMI. Understanding the correct formula is essential for accurate assessments in fitness and nutrition contexts.