Weighing in on Sleep
A good night’s sleep is as important as exercise or a healthy eating plan to
maintaining your optimum healthy weight and well-being. Sleep allows us to relax,
restore, and revitalize our bodies every night. We spend a third of our lives in sleep.
Sleep is an active state that affects physical and mental well-being. Sleep impacts
dramatically how we think, perform, learn, remember, and feel while we are awake.
When we sleep well, we awake refreshed and ready to go!
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Modern, busy lifestyles are stealing
our sleep time. According the 2005
Sleep in America poll, Americans are
averaging 6.9 hours a night. Long
work hours have reduced our sleep
by nearly 20%, according to the
National Sleep Foundation. Those
who get insufficient sleep are at
greater risk for weight gain even
though they exercise regularly and
generally eat a healthy diet. When
we are tired and sleep deprived, we
often try to maintain our energy level
with high sugar or high carbohydrate
food (such as cookies, doughnuts,
candy bars) for fast energy. We also
tend to eat when we are actually
sleepy, because we think fatigue is a
sign of hunger. Studies in animals
and humans suggest that sleep
duration is an important regulator of
metabolism. Not getting enough
sleep appears to affect the
hormones that regulate feeling full
(leptin) and hunger (ghrelin) so that
we tend to eat too much with sleep
loss.
Chronic sleep loss has other and
multiple effects on the body.
Inadequate sleep is linked to
decreased levels of growth hormone
that is released during deep sleep.
Reduced levels of growth hormone
seem to encourage weight gain.
Chronic sleep debt also prompts the
body to create excess insulin.
Excess insulin promotes the storage
of body fat and contributes to the
development of obesity,
hypertension, and Type 2 diabetes
According to the 2003 Sleep in
America poll, adults who report
having diabetes, heart disease, and
hypertension are more likely to
report sleep problems or diagnosed
sleeping disorders than those who
have not been diagnosed with those
diseases. If you are overweight or
obese and have a sleep disorder,
such as obstructive sleep apnea;
losing as little as 10 % of your
weight will improve your sleep.
What is good sleep?
Each sleep cycle takes about 90
minutes and is composed of two
parts, Non-Rapid Eye Movement
(NREM) sleep and Rapid Eye
Movement (REM) sleep. Each has
special functions. A good night’s
sleep means 4 to 5 cycles should be
completed each night.
When it is time to sleep, the brain
begins to slow down, our bodies
relax, and within 5-10 minutes, we
begin to fall asleep in stages.
Stages 1-4 are known as Non-Rapid
Eye Movement (NREM), or slow
wave sleep.
and blood flow to brain increase. At
the same time, a message is sent to
our muscles to keep them from
moving as we experience our
dreams.
Stage 1- the lightest stage of sleep.
Brain activity is characterized by
alpha waves. Often this is described
like being in the twilight zone.
In REM sleep
Stage 2- brain activity continues to
slow and the body relaxes further.
Stage 3- Delta waves –low
frequency /high voltage waves –
occur then disappear and we begin
to enter deep sleep. This takes about
30 minutes
Stage 4- is the deepest level of
sleep, and we are barely aware of
any outside stimulation.
What happens during deep sleep
(NREM sleep)- Muscles are relaxed.
 Blood pressure drops.
 Pulse and breathing slow
down.
 Body temperature decreases
to conserve energy.
 Digestion and metabolism
are slowed to allow for
physical repair.
 Growth hormone and other
hormones are released to
promote tissue growth and
repair.
Next we begin REM sleep, when we
experience most of our dreams.
This is a very active state where
breathing, blood pressure, pulse rate
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Memory benefits.
Brain chemicals called
neurotransmitters are
replenished.
Ideas are organized.
Problems are resolved.
Neural circuits are stimulated
and developed.
Good mental and emotional
stability are maintained.
Do you get enough sleep? In order
to prevent obesity getting enough
sleep may be especially important
for young adults age 27- 40 years. A
longitudinal study in Switzerland
followed almost 500 young adults
from age 19 and found an
association between short sleep
durations and being overweight. This
association diminished after age 40.
Recommended hours of sleep for
different age groups
Age
Infants
1-2 years
3-5 years
10 years
12-18 years
19-65 years
65+
Hours of Sleep
16-18 hrs
14-15 hrs
10-13 hrs
10 hrs
8-9 hrs
7-8 hrs
7-8 hrs
Some tips for a healthy sleep
environment—
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Create a calm routine just
before bedtime. Take a bath,
read a novel, listen to music.
Avoid exercising or work in
the late evening. This makes
quality sleep more elusive.
The bedroom should be used
for sleep and sex only. Make
sure your pillow and mattress
are comfortable and provide
good support. Your bedroom
should be cool, dark and
comfortable.
Eat a light snack such as
fruit, turkey, or whole wheat
toast.
Avoid sleeping with pets.
Let your health care provider know if
you snore or have ever been told
you stop breathing during sleep.
This may indicate a sleep disorder
that can be treated and help you
achieve adequate restful sleep. For
more information about programs
that promote health and well-being,
contact your county Extension office.
References:
Gregor, H; Buysse, DJ; Klaghofer, R;
Gamma A… The Association between Short
Sleep Duration and Obesity in Young Adults:
a 13-year Prospective Study. Sleep, 2004
27(4) 661-666.
National Sleep Foundation. 2005 Sleep in
America Poll.
http://www.sleepfoundation.org/_content/hott
opics/2005_summary_of_findings.pdf
Spero, D. Getting the Sleep You Need.
Diabetes Self-management. March/April
2005 25-33.
Spiegel, K;Tasali, E; Plamen P; Van Cauter,
E. Brief Communication: Sleep Curtailment
in Healthy Young Men is Associated with
Decreased Leptin Levels, Elevated Ghrelin
Levels, and Increased Hunger and Appetite.
Annals of Internal Medicine. 2004 141(11)
846-850.
Prepared by:
Zaida Belendez, N.D., R.N.
Extension Specialist in Health
Family & Consumer Sciences Extension
Assistant Professor, School of Public Health
College of Medicine
Issued December 2003; Revised May 2005
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