The Perils of
the Midnight Muncher
By Dr. Caroline Cederquist
Naples, FL
Do you know one of
those people who never seem to eat, no breakfast,
no lunch, little snacking throughout the day. Maybe
you are one of these people, always declining the
lunch invitation, and all day long, you are never
really hungry, or not so hungry that you feel you
need to respond to it.
But perhaps over the years, you have nevertheless
accumulated excess weight, maybe even quite a lot
of it. And it may be as much a mystery to you as
to others, who wonder quietly : How is that happening?
I never see him eat? And you might wonder yourself.
I eat nothing all day long, so where are all these
calories coming from??
Calories lurking
in the night
As is true for most
of us, the calories are coming from the kitchen.
But for folks with an odd disorder called Night-Eating
Syndrome (NES), those calories sing an especially
alluring song after the sun goes down. Most people
have the experience of the occasional midnight snack,
but if you find yourself with your head in the fridge
night after sleepless night, and fretting as your
weight increases in spite of your meager food intake
all day, you may be a victim of NES.
First described in the medical literature back in
1955, NES is characterized by three main features:
a lack of appetite in the morning, overeating in
the evening, and insomnia at night.
NES is not particularly rare. While the prevalence
of NES in the general population is estimated at
about 1.5 percent, among overweight folks, it is
far more common. One study reported 8.9 percent
of patients in a weight-reduction clinic and12 percent
of overweight patients visiting a nutrition clinic
were diagnosed with NES. And fully 26.5 percent
of the subjects classified as severely overweight
were diagnosed with NES.
Although not everyone with NES is overweight, a
study comparing normal weight and overweight night-eaters
against control subjects found that the main difference
between the overweight and normal-weight NES subjects
was age. The overweight night eaters had simply
been at it longer, and investigators found that
more than half of the older NES patients specifically
recalled that their night-eating preceded their
weight gain.
Interestingly, the chief difference between the
normal weight night-eaters and the study’s
control subjects with normal eating patterns was
that the NES group consumed more calories overall
in any 24-hour period.
This is consistent with other studies of breakfast
skippers, who say they don’t feel hungry in
the morning, and often convince themselves that
with breakfast behind them, that is one meal’s
worth of calories they have escaped for the day.
On the contrary, study after study has shown that
people who skip breakfast have higher caloric intake
overall in any given 24-hour hour period. The ‘skipped’
calories just show up at some point later in the
day, and they bring their friends! It seems that
it works pretty much the same with night eaters.
Behavioral
and chemical markers of NES
What distinguishes
the night eaters from other daytime meal skippers
is that the primary hallmark of NES is insomnia
- not just difficulty in falling asleep, but frequent
awakenings during the night. Like many people with
depression, most night eaters can trace the beginnings
of their insomnia problems to a period of elevated
stress, such as a job loss, relationship break-up
or any of the many other curve balls life slings
at us. But NES patients report that their mood is
lower in the night and early morning, and that differs
from people diagnosed with simple depression.
NES sufferers also report that they feel driven
to snack during these nighttime wakeful periods,
and that their nocturnal fridge-foraging expeditions
are particularly focused on high-carbohydrate foods.
Peanut butter and jelly sandwiches feature prominently
among the prey of nighttime snack hunters.
So armed with these life-history reports from night-eaters
themselves, investigators set out to identify physiological
and biochemical measures that might distinguish
night-eaters from the general population.
They were not surprised to find that NES sufferers
had significantly lower levels of melatonin, a hormone
produced by the brain’s pineal gland, and
intimately involved in the control of sleep-wake
cycles. The levels of melatonin decline with increasing
age, and this is consistent with the increased incidence
of sleep problems and overweight in general among
the middle-aged to elderly.
Midnight munchers also had lower levels of circulating
leptin, a hormone that has a central role in fat
metabolism, and their cortisol levels were higher.
Cortisol is the major natural glucocorticoid in
humans, our primary stress-response hormone. This
finding surprised neither the patients nor the investigators,
because so many of the night eaters reported that
their moonlight foraging expeditions began during
periods of elevated stress.
Still, a lot of us have stressful periods in life
and we don’t become nocturnal eaters. But
in NES sufferers, their internal clock seems to
have gone out of whack. Our ‘circadian rhythms’
are the patterns of daily activities and functions
that are influenced by the changes in light and
dark, temperature, etc., over the course of a 24-hour
day.
What appears to happen in NES is that the circadian
pattern of sleep stays normal (nighttime) but that
the circadian pattern of appetite becomes out of
phase by 6 hours or so, resulting in its overlap
on the sleep cycle. It is not understood exactly
how this happens initially, but scientists can reproduce
this phenomenon in experimental animals.
Sometimes our bodies are smarter than we think.
The finding that night-eaters have a strong preference
for high-carbohydrate snacks - yes, even more than
the usual high-carb American diet, with a 7:1 carbohydrate-to-protein
ratio among NES sufferers - led several investigators
to suggest that the high-carb snacks may be the
body’s attempt to increase the levels of tryptophan,
an amino acid essential to both sleep and mood.
So that peanut-butter and jelly sandwich may be
an attempt at self-medication.
Treating NES
Of course, all
the clear results that investigators have noted
also suggest some obvious possibilities for therapy
- and that’s the good news.
A number of medications, supplements and behavioral
strategies have been useful for NES sufferers. As
with any other kind of weight-management approach,
there is not a single magic bullet that works for
everyone, but there are some that have worked pretty
consistently.
Actual melatonin and leptin supplementation has
been moderately effective, and a fairly obvious
approach to try, since NES folks are measurably
low in these substances. Among studies of herbal
preparations, only kava-kava and valerian made it
into the moderately effective class, and the investigators
acknowledged that these were anecdotal reports from
only 46 patients.
Pharmaceutical approaches tend to be aimed at making
more serotonin available to the brain through varied
medications, of which sertraline has been most effective.
After 12 weeks of treatment, sertraline had reduced
the number of awakenings from 14.3/week to 5.9;
and the number of nocturnal ingestions from 10.8
per week to 3.7. And NES sufferers circadian rhythms
seemed to begin to correct themselves, as well,
with the percent of daily calories consumed after
supper cut by about half.
And finally, exercise and gentle relaxation training
has also been shown effective in helping NES sufferers
to help overcome insomnia and restore their natural
sleep cycle, helping to alleviate the restless night
eating that has caused that slow, mysterious gain.
(Caroline J. Cederquist, M.D. is a board certified
Family Physician and a board certified Bariatric
Physicians,the medical specialty of weight management.
She specializes in lifetime weight management at
the Cederquist Medical Wellness Center, her Naples,
FL private practice. You can also get more information
about Dr Cederquist and her weight management plan
by visiting www.DietToYourDoor.com
She is the author of Helping Your Overweight Child
- A Family Guide, which is available at, DrCederquist.com,
Amazon.com, or by calling toll-free 1-800-431-1579.
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