Why Body Mass Index is Inaccurate and Misleading

By  | 

BMI/ Body Mass Index is considered as a measure of body fat based on an individual’s weight about height. It has been a well-established method of measuring the relative size of a body ever since its invention. It gained popularity due to being simple but also an inexpensive and a noninvasive surrogate measure of body fat.

However, the Body-Mass Index has also been subject to a significant amount of criticism for various well-elaborated reasons in today’s date. Approximately every several months, comments by a nutritionist or well-known doctors strike up debates regarding why the Body Mass Index is flawed and must be replaced.

Why Body Mass Index is Inaccurate and Misleading

Body Mass Index


Critics argue it is too simple of a measure. Factors such as gender, age, past medical history, lifestyle factors including diet, levels of psychical activity. Even family history, are all equally important in helping to determine an individual’s relative size with precision and accuracy. Which the Body Mass Index does not take into consideration.


Body-Mass Index is a measure of relative weight, fat mass and muscle mass, as a result, are not distinguished. Any individual that has a calculated BMI between 18.5-25 are categorized as being normal in weight while people that lie between a BMI of 25-30 are labeled as overweight and more prone to diseases.

BMI has also been called as a controversial measure due to the categorization of different weight categories. During the mid-1980’s, several boundaries were set by scientists Webster and Garrow.

They attempted to draw a line to cut-off what is healthy, and what is unhealthy. However, this clear-cut division based on a limited number of elements has been argued to be an arbitrary exercise.

Any BMI calculated for individuals as being higher than 30 are simply considered to be obese. It has been well-established that those suffering from obesity are more prone to developing different heart conditions, cancer, type 2 diabetes and other diseases that can prove to be fatal.

Inaccuracies occur however since Fat mass or muscle mass are not included within the equation of calculating the Body Mass Index.

This can be further explained with the example of a Bodybuilder who, due to a higher level of muscles mass may weigh more and hence seem obese in agreement with his calculated BMI number. While an aged person’s BMI, may appear to be in a healthier range (<27) due to excessive muscle loss.

Muscle is denser than fat and hence will evidently weigh more. Thus BMI calculations tend to divide athletics with a muscle build as being fatty and unhealthy.

BMI fails to incorporate the division of body weight, or more specifically even the body-type of an individual’s body as being a key factor of indicating health risks.

Those of whom that tend to deposit a majority of their body weight at the midsection are called ‘Apple-shape.’ They are considered to be more prone to contracting a disease or early mortality in comparison to the so-called ‘pear-shaped.’

Pear shaped are those body-types that tend to deposit their weight more peripherally, the lower body and glutes in particular. Thus, a BMI of 32 kg/m2 of two separate individuals could have drastically different body shapes, and hence differently ranging risk of diseases and early mortality.

Keeping the earlier mentioned reasoning and evaluation in mind, It is safe to say that the BMI calculator can not be considered as a reliable form of measuring body types especially while measuring athletic body types.

The Introduction of Body Adiposity Index which calculates estimated body fat by height measurements and hip-width unlike bodyweight has already started to place the BMI under threat. Unless modifications are made to the equation used to calculate BMI, the BAI might ultimately replace the 200-year old BMI.


This post was written by Beth Martel. She is a mother of two, a medical professional and a humanitarian. She blogs at

Related Posts Plugin for WordPress, Blogger...



The chief editor here at Billboard Health, wife and Mother of 1, Nutritionist and goal getter.

Leave a Reply

Your email address will not be published. Required fields are marked *