By Dr. Mercola
Too little sleep is known to impact your eating habits,
appetite, weight gain and other metabolic functions, but little
is known about whether different diets play a role in how well
you sleep. A new study evaluated the diets and sleep patterns of
more than 4,500 people and found distinct dietary patterns among
short and long sleepers.1
Do People Who Sleep Less Eat Differently Than Those Who Sleep
More?
While the study was only able to generate hypotheses about
dietary nutrients that may be associated with short and long
sleep durations, it did yield some interesting data.
Participants were grouped into four sleep groups:
- Very short (less than 5 hours a night)
- Short (5-6 hours)
- Normal (7-8 hours)
- Long (9 or more hours)
Here are some of the dietary characteristics uncovered about
each sleep group:
- Very short sleepers: Had the least food
variety, drank less water and consumed fewer total
carbohydrates and lycopene (an antioxidant found in fruits
and vegetables).
- Short sleepers: Consumed the most
calories but ate less vitamin C and selenium, and drank less
water. Short sleepers tended to eat more lutein and
zeaxanthin than other groups.
- Normal sleepers: Had the most food
variety in their diet, which is generally associated with a
healthier way of eating.
- Long sleepers: Consumed the least
calories as well as less theobromine (found in chocolate and
tea), choline and total carbs. Long sleepers tended to drink
more alcohol.
As for what the data means, researchers aren’t yet sure.
They’re using it as more of a starting point from which to base
future research:
“Future studies should assess whether these
associations are due to appetite dysregulation, due to
short/long sleep and/or whether these nutrients have
physiologic effects on sleep regulation.
In addition, these data may help us better understand
the complex relationship between diet and sleep and the
potential role of diet in the relationship between sleep and
obesity and other cardiometabolic risks,” they said.
Certain Foods are Known to Help Promote (and Disturb) Sleep
Many people grew up drinking a glass of warm milk before bed
to help lull them into sleep, and you may have “graduated” as an
adult to a cup of warm chamomile tea, which is known for its
calming properties.
Certain foods, too, are known for their sleep-inducing
effects. Cherries, for instance, are a natural source of the
“sleep hormone” melatonin, and drinking tart cherry juice has
been found to be beneficial in improving sleep duration and
quality.2
Alternatively, almonds and spinach are rich in magnesium, which
is known for promoting sleep and relaxing muscles.
Of course, the converse is also true in that certain foods
can significantly interfere with your sleep. Anything with too
much caffeine would certainly be among them, but so would spicy
foods before bedtime, which are linked with more time spent
awake during the night and taking longer to fall asleep.3
In general, you want to avoid before-bed
snacks, particularly grains and sugars. These will raise your
blood sugar and delay sleep. Later, when blood sugar drops too
low (hypoglycemia), you may wake up and be unable to fall back
asleep.
How Sleep Impacts Your Appetite and Your Weight
If you’re someone who likes to “burn the midnight oil,”
either by choice or because you have difficulty sleeping, you
probably expect it to make you feel groggy and irritable the
next day. But did you know that it can also seriously alter your
appetite?
When you're sleep deprived, leptin (the hormone that signals
satiety) falls, while ghrelin (which signals hunger) rises. In
one 2010 study, researchers found that people who slept only
four hours for two consecutive nights experienced:4
- 18 percent reduction in leptin
- 28 percent increase in ghrelin
This combination leads to an increase in appetite.
Additionally, sleep deprivation tends to lead to food cravings,
particularly for sweet and starchy foods. Researchers have
suggested that these sugar cravings stem from the fact that your
brain is fueled by glucose (blood sugar); therefore, when lack
of sleep occurs, and your brain is unable to properly respond to
insulin (which drives glucose into brain cells) your brain
becomes desperate for carbohydrates to keep going.
If you're chronically sleep deprived, consistently giving in
to these sugar cravings will virtually guarantee that you'll
gain weight. Further, according to research published in the
Annals of Internal Medicine,5
after four nights of sleep deprivation (sleep time was only 4.5
hours per night), study participants' insulin sensitivity was 16
percent lower, while their fat cells' insulin sensitivity was
30 percent lower, and rivaled levels seen in those with
diabetes or obesity.
This too is a surefire way to gain weight, as the insulin
will seriously impair your body's ability to burn and digest
fat. It also increases your risk of diabetes. In short, sleep
deprivation puts your body in a pre-diabetic state, which can
lead to increased weight and decreased health.
When You Eat May be as Important as What You
Eat
Emerging research suggests that the timing of your meals, for
instance eating very late at night when you'd normally be
sleeping, may throw off your body's internal clock and lead to
weight gain. For instance, artificial light, such as a glow from
your TV or computer, can serve as a stimulus for keeping you
awake and, possibly, eating, when you should really be asleep.
In one study, mice that were exposed to dim light during the
night gained 50 percent more weight over an eight-week period
than mice kept in complete darkness at night.6
They also had increased levels of glucose intolerance, a marker
for pre-diabetes. The weight gain occurred even though the mice
were fed the same amount of food and had similar activity
levels, and the researchers believe the findings may hold true
for humans as well.
When mice were exposed to nighttime light, they ended up
eating more of their food when they would normally be sleeping
and this lead to significant weight gain. However, in a second
experiment when researchers restricted meals to times of day
when the mice would normally eat, they did not gain weight, even
when exposed to light at night.
In other words, while it's typically thought that your
biological clock is what tells you when it's time to wake up or
go to sleep, light and dark signals actually control your
biological clock. In turn, your biological clock regulates your
metabolism. So when your light and dark signals become disrupted
it not only changes the times you may normally eat, it also
throws your metabolism off kilter, likely leading to weight
gain.
Are You Better Off Eating Your Biggest Meal at Night?
We’ve all heard the advice that breakfast is the
most important meal of the day. But some experts believe that
skipping breakfast and
eating your main meal at night may actually be more in-tune
with your innate biological clock. Routinely eating at the
wrong time may not only disrupt your biological clock and
interfere with your sleep, but it may also devastate vital body
functions and contribute to disease.
According to Ori Hofmekler, author of
The Warrior Diet:
“Your body is programmed for nocturnal feeding. All
your activities, including your feeding, are controlled by
your autonomic nervous system, which operates around the
circadian clock. During the day, your sympathetic nervous
system (SNS) puts your body in an energy spending active
mode, whereas during the night your parasympathetic nervous
system (PSNS) puts your body in an energy replenishing
relaxed and sleepy mode.
These two parts of your autonomic nervous system
complement each other like yin and yang. Your SNS, which is
stimulated by fasting and exercise, keeps you alert and
active with an increased capacity to resist stress and
hunger throughout the day. And your PSNS, which is
stimulated by your nightly feeding, makes you relaxed and
sleepy, with a better capacity to digest and replenish
nutrients throughout the night. This is how your autonomic
nervous system operates under normal conditions.
But that system is highly vulnerable to disruption.
If you eat at the wrong time such as when having a large
meal during the day, you will mess with your autonomic
nervous system; you'll inhibit your SNS and instead turn on
the PSNS, which will make you sleepy and fatigued rather
than alert and active during the working hours of the day.
And instead of spending energy and burning fat, you'll store
energy and gain fat. This is indeed a lose-lose situation.”
Are You Eating Right for Restful Sleep?
Researchers are only beginning to tease out the complex
relationship between your diet and your sleep, but it did appear
that one similarity among the “normal” sleepers was attention to
eating a varied diet. If you need some help in this area, check
out my
nutrition plan for a step-by-step guide to optimizing your
eating habits.
And, if you need tips for getting a more restful night’s
sleep, be sure to read my
33 secrets to a good night’s sleep.
© Copyright 1997-2013 Dr. Joseph Mercola. All Rights Reserved.