Several anthropometric methods that measure adiposity use body measurements to
estimate body fat percentages. These methods have the advantage of simplicity. For
example, waist circumference has been shown to correlate well with health risks.
Even so, the accuracy of determining body fat percentage is limited because body
fat is not directly measured. Many of us use what could be considered an anthropometric
method when we look in the mirror to evaluate our fatness and when we
recognize that our clothes fit too tightly or are getting loose.
A simple way to measure the extra-important visceral fat is by measuring waist
and hip size. A good proxy for too much abdominal fat in adults is a waist size of
35 inches or greater for women and 40 inches or greater for men. Another good
measure is the waist-to-hip ratio. It should be 0.8 or less. A ratio of 0.85 or greater
in women and 1.0 or greater in men is a warning sign of too much visceral adipose
tissue (VAT), and potential insulin resistance and metabolic disease.
There are several other ways to estimate adiposity, but they require specialized
equipment. Bioelectric Impedance Analysis, or BIA, is based on the fact that muscle
is more conductive than fat. Some weight scales you can buy are BIA capable, but
the test has considerable variability based on a person’s state of hydration.
Hydrostatic Weighing is considered to be an accurate method of body fat measurement.
It requires comparing a person’s weight on a scale in the air with their weight
when underwater. The estimation works because body fat increases buoyancy—a
person with a larger percentage of fat-free mass will weigh more in the water than
to a person with a larger amount of fat. Air-displacement plethysmography also
works on the same principle as underwater weighing. The subject sits in a small
machine that measures how much air is displaced by the individual, and this allows
a similar calculation of body density.
The gold standard of body fat measurement is Dual Energy X-ray Absorptiometry,
known as DEXA Scanning. In addition to measuring fat-free soft tissue mass and
fat tissue mass, it can also be used to measure bone mineral mass and can detect
osteopenia (mild bone loss) and osteoporosis (severe bone loss). DEXA also makes
it possible to see where fat is distributed in the body.
Recent research compared accurate whole-body and abdominal fat data from DEXA
with other predictors of whole-body fat and visceral adipose tissue. The study
found that the waist-to-height ratio (WHtR) is the best anthropomorphic predictor
of both visceral adipose tissue and whole-body fat mass percentage in both men
and women. A waistline slightly greater than half of a person’s height (0.53 in men
and 0.54 in women) was found to indicate whole body obesity. The ratio indicating
abdominal obesity was 0.59 in both sexes. In the small sample of the study, a higher
proportion of subjects were found to have obesity than was indicated by BMI calculations.
The study showed that not only is WHtR more accurate than BMI; it is
also easy to use.
One study using the standard of waist measurement greater than half of height found
that an alarming 90% of men, 80% of women, and half of children in the U.S. are
overfat, a category broader than overweight or obesity because it includes people
who seem to be of normal weight but have excessive unhealthy abdominal fat.
This blog presents opinions and ideas and is intended to provide helpful general information. I am not engaged in rendering advice or services to the individual reader. The ideas, procedures and suggestions in that are presented are not in any way a substitute for the advice and care of the reader’s own physician or other medical professional based on the reader’s own individual conditions, symptoms or concerns. If the reader needs personal medical, health, dietary, exercise or other assistance or advice the reader should consult a physician and/or other qualified health professionals. The author specifically disclaims all responsibility for any injury, damage or loss that the reader may incur as a direct or indirect consequence of following any directions or suggestions given in this blog or participating in any programs described in this blog or in the book, The Building Blocks of Health––How to Optimize Your Health with a Lifestyle Checklist (available in print or downloaded at Amazon, Apple, Barnes and Noble and elsewhere). Copyright 2021 by J. Joseph Speidel.