Society tells us that being overweight is bad. However, even though
obesity is linked to many chronic health problems (i.e., type II diabetes,
heart disease, etc.), the key word is “linked”, which means the medical
community can’t come out and say for sure that being overweight is the cause of
these diseases. One of the major purveyors of excess weight = bad myth is the
body mass index (or the BMI), which states BMIs lower than 18.5 is
underweight, BMIs between 18.5 and 24.9 is normal, BMI ranging 25 to 29.9 is
overweight, and 30 or above BMIs are considered obese. Here are six BMI myths
that we should stop giving any weight to…
Myth 1: Healthy Diet and Regular Exercise Means Low BMI
The major issue I’ve had time and time again with the BMI is that many
of my very visually fit friends and family members report a BMI in the “obese”
range due to muscle mass.
We all know that muscle mass weighs
more compared to fat mass. It also makes perfects sense then that if we start
working out and eating better we may gain muscle mass, and weigh more, not
less. According to an official statement from the Rudd Center for Food Policy & Obesity, “People can be healthy at different body sizes.”
Myth 2:
BMI is a Valid Measure of Health
Very obviously the BMI doesn’t work
for every body, which is why many health experts assert that it can’t
possibly be used as an accurate way to measure health.
Focusing on a number on the scale can
cause health to be “oversimplified”, according to Dr. Rebecca Puhl, deputy
director at Philidephia’s Rudd Center for Food Policy & Obesity, “and
[doctors] can ignore other pieces of information, and even blame or
stigmatize patients.”
Myth 3:
BMI and Heart Disease Risk
Many people, health care
professionals included, believe that an overweight BMI reading means higher
heart disease risk. However, that’s not always the case, according to this 2016
study out of Umea University, which was published by ScienceDaily.com.
The Umea University study monitored
the instance of heart attacks, and deaths among 4,046 pairs of
identical twins for a 12-year duration. The findings revealed that that those
with high BMIs had no more increased risk than their thinner twins—researchers
reported 203 heart attacks and 550 deaths among the high BMI
participants and 209 heart attacks and 633 deaths among participants with low
BMIs.
Myth 4:
Health Can be Determined by a Scale
One of the first things I used to
tell my personal training clients at the gym I worked at was, “throw away your
scale”. I think scales can be of use when you’re baking and need a precise
amount of ingredients, but as human beings our health simply can’t be
determined by broad scales.
The BMI guidelines were
re-established by the National
Institutes of Health in
the year 1998, based solely on government recommendations to establish
a global standard for healthy and unhealthy weight, the reasoning
behind it somewhat dubious. “There’s no single number that can represent a healthy weight,”
says Dr. Rexford Ahima, medical professor at Philadelphia’s University
of Pennsylvania, “it depends on starting weight, genetics and gender,
[and so many] other factors.”
Myth 5:
Low BMI = Healthy
Having a high BMI doesn’t
necessarily mean you’re unhealthy, just like having a low BMI doesn’t
necessarily mean you’re healthy. OK, there may be a correlation
between obesity and health issues like high blood sugar, blood pressure, and
high cholesterol, but assuming a patient is healthy due to a low BMI can be
problematic for health care professionals.
For instance, this 2011 weight study
published by the Nutrition Journal studied the
correlation between elevated BMI and health conditions like high blood sugar
and high blood pressure. The study monitored the health of 40,000 adults
and found that a large majority of participants who registered as “obese”
on the BMI scale had perfectly healthy cholesterol, blood sugar,
and blood pressure numbers.
Myth 6: BMI Medical
Assumptions
California-based nutrition, weight,
and health professor, and author of the book Dr. Linda Bacon, PhD, author of
the book Health at Every Size: The Surprising Truth About Your Weight, is an
expert on the effects of weight stigma and how it impacts our health.
According to Dr. Bacon, misdiagnosis
by doctors is a major issue with weight stigma and tools like the BMI. [Many
are] misdiagnosed,” she explains, due to doctors assuming patients
with normal body weights are healthy and not examining these patients
for issues like elevated blood sugar and cholesterol.
