The graphic that shows why BMI is useless: Scientists reveal how radically different body shapes can have the SAME readings

  • The graphic shows full-body scans of six people, all with a BMI of 25.4
  • Each body looks different because muscle and bone are denser than fat
  • In the graphic, for instance, some people carry more weight in their legs
  • Because BMI only considers height and weight, it overlooks these factors

By Ellie Zolfagharifard For Dailymail.com

Published: 18:00 EST, 7 July 2015 | Updated: 19:47 EST, 7 July 2015

Most of us step on the scales to check how much we've indulged ourselves over the holidays.

Doctors, however, rely on the Body Mass Index (BMI), which involves dividing weight in kilograms by height in metres squared.

For centuries this has been the standard against how our health has been measured – but a new graphic has revealed just how inaccurate it can be.

You can calculate your own BMI using this visualiser:

WHAT DOES YOUR BMI MEAN?

A reading of between 18.5 and 25 indicates healthy weight. 

From 25 to 30 is classed as overweight, and over 30 is obese. A reading below 18.5 means you're underweight. 

But scientists are increasingly saying BMI figures are inaccurate because it overlooks muscle denisty. 

For example, a supremely fit and muscly athlete might be classed as obese despite carrying little or no body fat, simply because muscle is more dense than fat.

New York-based firm, Body Labs, has created a graphic revealing scans of six people to show how the same BMI can look very different on different bodies.

Each of the volunteers was 5 feet 9 inches tall and 172lbs (78kg). All had the same body mass index of 25.4, meaning they could all technically be considered overweight.

According to official health guidelines, people with a BMI of over 25 are overweight and those with a BMI over 30 are considered obese.

But the same BMI can look different because muscle and bone are denser than fat. Some people in the image, for instance, carry more weight in their legs.

Because BMI only considers height and weight, it overlooks these factors.

‘Since BMI doesn’t take body mass composition or distribution into account, it is basically blind to fitness level and body shape,’ Body Labs wrote in a blog post.

‘You probably won’t be found to be obese when you’re actually underweight, but for people who are borderline, being misplaced is easy.

‘For example, you can be an athlete in great shape and be deemed overweight or even obese.

‘Or, you could have an average BMI but carry a significantly higher amount of mass in your torso, which as some studies show can be a predictor of health risks such as cardiovascular disease or diabetes.’

BMI places top class athletes, sprinters and rugby players, in the same weight and height grouping as people who do not exercise at all.

These illustrations were created from scans of real people by New York City based startup Body Labs. The number labeled V is the amount of fluid that would fill a container the same size as their body, in litres

These illustrations were created from scans of real people by New York City based startup Body Labs. The number labeled V is the amount of fluid that would fill a container the same size as their body, in litres

A heatmap comparison of person 2 to person 1. The heatmap coloring represents the point-to-point distances between the same points on both of their bodies. Blue means their bodies were the same, and hot pink means they differed greatly. You can see their bodies varied most in their stomachs, backs and back of legs

A heatmap comparison of person 2 to person 1. The heatmap coloring represents the point-to-point distances between the same points on both of their bodies. Blue means their bodies were the same, and hot pink means they differed greatly. You can see their bodies varied most in their stomachs, backs and back of legs

For instance, even in his prime, rugby star Jonny Wilkinson was reportedly classed as overweight according to his BMI.

Many nutritionists now argue that body fat percentage and body composition are a better sign of health that the figure on the scales.

Using a piece of string to find out if you are in proportion might be a better way to see if you are fat than working out your Body Mass Index (BMI).

In May, a study suggested that people should check their health by taking a piece of string the same as length as their height.

The scientists at Oxford Brookes University said that by folding the string in half and then seeing if you can easily get it round your waist may be a better way to find out if you are an unhealthy size than BMI.

International studies have shown in the past that a person is at a lower risk from heart disease if their waist measurement is less than half their height.

FAMOUS BMIS REVEALED
Name  Height (ft, in) Weight (lb) BMI 
Usain Bolt 6'5" 207 24.5
Kim Kardashian5'2"  139 25.4
Serena Williams 5'9"  150 22.1
Tom Brady6'4"  225 27.4
Gisele Bundchen5'11"  126 17.6
Barack Obama 6'1" 180 23.7
According to BMI calculations quarterback Tom Brady is overweight, with a BMI of 27.4 and his model wife Gisele Bundchen, seen here at the 2014 Met Ball, is underweight with a BMI of 17.6

According to BMI calculations quarterback Tom Brady is overweight, with a BMI of 27.4 and his model wife Gisele Bundchen, seen here at the 2014 Met Ball, is underweight with a BMI of 17.6

A reading of between 18.5 and 25 indicates healthy weight. From 25 to 30 is classed as overweight, and over 30 is obese. A reading below 18.5 means you're underweight. But scientists say BMI may not be as accurate an indication of health as you may think

A reading of between 18.5 and 25 indicates healthy weight. From 25 to 30 is classed as overweight, and over 30 is obese. A reading below 18.5 means you're underweight. But scientists say BMI may not be as accurate an indication of health as you may think

The formula for BMI is weight in kilograms divided by height in meters squared. Because height is commonly measured in centimeters, divide height in centimeters by 100 to obtain height inches

The formula for BMI is weight in kilograms divided by height in meters squared. Because height is commonly measured in centimeters, divide height in centimeters by 100 to obtain height inches

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