It’s finally time to forget about the Body Mass Index (BMI), which is far too simplistic and overly general. Or at least this is what was suggested by a team of researchers who recommend a new system, measuring body composition and the distribution of weight: the Body Volume Indicator (BVI).
Developed by Adolphe Quetelet at the beginning of the 1800s, the BMI is fairly easily calculated: divide your weight in kilograms by the square of your height in meters. For a person weighing 55 kg, measuring 1 meter 65 cm, for example: 55 kg/(1.65m x 1.65 m) = 55 kg/2.7225 = 20.20 kg/m2. This number falls within the “normal” body mass index range, as 18.5 kg/m2 to 25 kg/m2 is considered normal. The other categories range from very severely underweight to very severely obese. But is the BMI a genuinely good measure? It is often criticised for being too simplistic to provide precise information as to a person’s health. This is why a new system for measuring body composition and weight distribution is being recommended: the Body Volume Indicator (BVI).
Contrary to the BMI, which is calculated by relating a person’s weight to their height, the BVI includes “other crucial factors such as the fat mass, lean mass and weight distribution when determining a person’s body composition”, explains Joseph Medina-Inojosa, a specialist in cardiovascular research in the Mayo Clinic. As well as weight and height, information about the waist to hip ratio, the total percentage of body fat and the volume of the abdomen are taken into account when calculating a score. “These measures are more difficult to take compared to weight and height, of course, but technology has progressed since the 19th century. And it guarantees a more precise measure”, continues the researcher.
Select Research, a pioneering company in the area of 3D body measurements, recently collaborated with the Mayo Clinic (an American university hospital and research foundation) to launch an app that will allow anyone to measure their own BVI. So how will it work? Doctors will take two photos of their patients, wearing only their underwear, and facing side on. Once the photos are taken, they are transformed into 3D body silhouettes and sent to a server where the images are compared with a database compiled from thousands of MRI images, 3D body scans and other information. The photos are then deleted.
By comparing the patients’ 3D silhouettes with this database, the app provides more detailed information regarding weight distribution, particularly in the abdomen, the area in the body “associated with the highest risk of metabolic illnesses and insulin resistance”, according to Medina-Inojosa. Many studies have in fact suggested that fat in the mid-section, that covers the organs, is associated with a higher risk of premature death than fat stored in other areas of the body. And none of this is taken into account by the BMI.