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singapore he alth
JUL⁄ AUG 2012
News
Find out your actual
metabolic rate
SGH kick-starts a new study to establish a more
accurate formula for calculating the metabolic
rates of Singaporeans
Me
as
ur
To lose or gain weight is a tricky balancing act that requires a correct
understanding of the body’s energy
needs. But the current standard measure
of the body’s metabolic rate used to calculate the body’s daily caloric requirement
doesn’t take into consideration the differences in body composition, and this can
mean an error of as much as 10 per cent
in the reading.
For that reason, said Miss Stephanie
Tan, Physiotherapist, and Clinical Coordinator, LIFE Centre, Singapore General
Hospital (SGH), the hospital has embarked
on a study to address the shortcomings
of the existing formula. Miss Tan, the
principal investigator of the study, hopes
to test at least 400 healthy Singaporeans between the ages of 18 and 65. The
results of the study, started in 2010 and
likely to close in August, will be used
to develop a formula for estimating the
metabolic or resting energy expenditure
rate of Singaporeans.
“People can take charge of their weight
if they know their metabolic requirements. It helps them understand the type
of lifestyle modifications they have to
take to reach their goals,” said Miss Tan.
Asian bodies tend to have more
body fat and less muscle than
their Caucasian counterparts. Muscle burns
more calories than
g
n
i
th
e
m
e
body fat, so a person with more fat and less
muscle will use fewer calories to perform
any activity, including eating, exercising
and sleeping, than a person with a similar
weight and height but with less fat and
more muscle. At a hospital, this can affect
the success of managing patients with
weight problems and providing patients
with the correct nutrition.
“If a patient’s resting metabolic rate
is overestimated, he may not achieve the
expected weight loss on the diet and exercise programme designed for him,” said
Miss Tan.
A diet and exercise programme based
on an inaccurate or wrong rate will be ineffective. Worse, not making the expected
progress after following a programme for
a while can demoralise patients who are on
a weight-loss programme to control their
long-term medical problems like hypertension and diabetes. “The patient may go
on a yo-yo diet or use inappropriate ways
to lose or gain weight,” said Miss Tan.
The body burns calories even at rest,
with 50 to 70 per cent of its total daily
energy needs used to carry out its basic
functions – breathing, circulating blood,
adjusting hormone levels, and growing
and repairing cells – and the rest for activities like walking, eating or exercising.
t
Build more muscle mass
As muscle burns more calories than
fat, building up more lean muscle will
help burn more calories every day.
Doing some weight-bearing exercises,
such as weight-lifting or walking, will
add muscle mass and burn calories.
To find out their body composition,
participants stand on a scale that
sends a harmless electric current
up through the body.
About 200 volunteers, including SGH
employees, have had their weight, height,
waist, hip and neck circumference, as
well as body fat-muscle composition measured, said Miss Tan. They also had their
resting metabolic rate, known as the resting energy expenditure rate, measured.
Some surprises have emerged from
the study at this early stage, said Miss
Tan. For instance, the investigators have
found that the margin of inaccuracy was
not uniform across the population, but
greater for smaller women. The reason
for this, however, is not known.
When completed, the study will
improve patient care in the hospital and
benefit the individual participant, said
Miss Tan. “A person who knows his resting metabolic rate can better tailor his
diet to match his energy intake with his
energy expenditure, which will help in
weight management,” she said.
ic rate at res
l
o
b
a
t
To measure the resting
metabolic rate, a small plastic hood or canopy
is put over the head of the participant who is lying down
on a comfortable bed. The canopy measures the amount of oxygen
and carbon dioxide breathed in and out by the participant.
This is based on the principle that gases and heat are produced and
used when the body expends energy to power its basic functions
while it is at rest. The participant has to remain still and quiet, but
not fall asleep during this test, which takes about half an hour.
People who are interested in taking part in the study
can call Miss Stephanie Tan at 6326-6794 or
email her at [email protected] for more information.
Generally, participants have to be healthy, and not pregnant or
experiencing significant weight loss or gain, to participate in the study.
They will need to spend a weekday morning at
SGH Lifestyle Improvement and Fitness Enhancement (LIFE) Centre,
and fast and refrain from smoking as well as moderate to
vigorous activity 10 hours before the test.
A sensible, balanced diet, regular
exercise and good sleeping habits can
give a boost to energy and lead to good
health. Other ways of boosting the
metabolism include:
Avoid skipping meals
Significantly decreasing the caloric
intake will slow the metabolic rate as
the body enters “fasting” mode and
reacts by hoarding fat and burning
lean muscle for energy.
Get adequate sleep
Not sleeping enough affects the
levels of appetite-regulating
hormones, and the capacity to
metabolise carbohydrates in the
body. The metabolic rate nosedives
as less fat is burned for energy.
Eat enough protein
Protein forms the building blocks
for muscle, and having inadequate
protein can lead to the loss of
desirable, lean muscle mass.
Drink less alcohol
Alcohol slows the fat-burning
process. The body needs to burn
calories from alcohol before fat can
be lost through diet and exercise.
Adapted from Beautiful Inside Out,
The SingHealth Guide to Women’s Health,
produced by Reader’s Digest for SingHealth.
By using a small plastic hood,
Miss Stephanie Tan (left) is able
to measure the amount of oxygen
and carbon dioxide a patient
breathes in and out while at
rest. She will use the data
to develop a formula
for estimating resting
metabolic rates.
PHOTOS: VERNON WONG
BY Jamie Ee
Turbo-charge
your metabolism!