Measurement methods and sources of error
Like other attempts to create tables with measurement values over the proportion of body fat, a BMI measurement is not quite perfect. It only measures the relationship between height and weight. It does not take into account levels based on body fat related to age, physical activity, muscle mass, or gender. For this reason, the formula may overestimate body fat in some cases while underestimating in other respects.
The BMI formula in its current form is still a practical measurement method and will be used for a long time to come. It matches very well with the vast majority of the population.
Other additions to the measurement method, such as waist circumference, can improve and assist the BMI value. However, the relationship between waist circumference and health risks is more difficult to measure. It is hard to make accurate calculations in a way that is consistent with large groups of individuals. This problem makes it challenging to use reliable formulas and tables. For those individuals who fall near the limit in the lower or upper range of the BMI index, we recommended contacting health care professionals for a more thorough assessment and potential treatment.
Click here to read more about BMI.