12
NEWS
BMI - why?
BMI never Intended as
a diagnostic tool.
Body mass index (BMI) was
intended to categorize
research participants on
the basis of their height
and weight, and not as a way to
determine health, argues Brandy W.
Root, a registered dietician based in
Florida USA.
She says, "BMI was developed by a
Belgian mathematician who wanted
to determine the metrics of the
average man to better understand
human physicality and social
aptitudes. No peer-reviewed research
exists stipulating that a BMI of 24.99
makes a person healthy, while a BMI
of 25 makes them unhealthy. But, in
our attempt to quantify all aspects of
the human condition for insurance
reimbursement, we have allowed BMI
to become a determining factor in
care."
The obvious concern with BMI
is that it only accounts for sheer
mass (or weight) and not the type
of mass. Excess body fat is linked
to increased risk for cardiovascular
disease, while excess muscle mass is
not, but we do not routinely assess
body composition; but simply look
at a patient's weight and give them
a stamp of 'normal', 'overweight',
or 'obese'. So, for example, those
working in construction or other
physically demanding jobs may be
exceptionally well muscled and
capable of impressive physical feats
but are marked as 'obese' because of
their BMI.
Bioelectrical impedance analysis*
- which involves allowing a weak
current to pass through the body
from the hands to the feet and
determines body composition on
the basis of the speed at which the
current travels through different
tissues - may be one alternative.
It may not be appropriate for all
patients, specifically those with
pacemakers, but it is generally an
accessible and accurate method to
retrieve quantitative measurements
of fat mass to track a patient's body
composition instead of just viewing
all weight the same way.
However, Root argues that medical
professionals should not get rid of
BMI from assessments if they want
patients to continue to receive the
best care, but that they should also
focus on other indicators of wellness
alongside BMI, such as weight loss
trends, blood pressure and frequency
of bowel movements. "Why am I not
referring to a patient's BMI? Because
it's as relevant to their health as their
preferred flavour of protein shake.
That's to say that it doesn't matter to
me. I am worried about my patients'
health and wellness, and BMI is at the
bottom of my list of concerns."
*Also referred to as body
composition scales, or smart scales.
To find out more, click HERE.