Updated: Sep 18, 2019
There may not be an obvious link between sleep deprivation and your weight, but more and more research is showing just how important sleep is for your mood, mental performance, overall health and wellness, and especially when it comes to maintaining a healthy weight.
Many studies show that people who have a short sleep duration simply weigh more. And, in fact, as the levels of chronic (long-term) sleep deprivation have increased over the past 50 years, so have the growing epidemics of being overweight or obese.
And many studies now agree that lack of sleep is an “independent” risk factor (i.e. a direct risk) for weight gain and obesity.
Especially for women.
One large analysis of 45 studies which included over 600,000 people says, “studies from around the world show a consistent increased risk of obesity amongst short sleepers in children and adults.” The increased risks were 89% for children and 55% for adults.
The overall data in that study suggests that a reduction in one hour of sleep per day would be associated with about 1.4 kg in additional weight.
Right now, 40% of American adults say that they get less than 7 hours of sleep per night, and 7 hours is the minimum recommended nightly sleep, with 9 being the maximum.
HOW SLEEP DEPRIVATION LEADS TO WEIGHT GAIN
Overall, there are two main ways (with two factors each) that we think that lack of sleep contributes to weight gain and obesity.
First, it increases calorie intake in two ways.
It allows more time available to eat; and
It messes with your hunger hormones.
Second, it decreases your ability to burn off calories in two ways.
It can slow your metabolism; and It can cause fatigue and, therefore, reduced physical activity.
Let’s talk about all four of these factors.
LACK OF SLEEP INCREASES TIME AVAILABLE TO EAT
Some researchers suggest that the longer the time you’re awake, the more opportunity you have to eat, or more specifically, to snack. In fact, some studies have shown that these tend to be nighttime snacks.
And guess what many sleep-deprived people tend to snack on at night? You guessed it...high-fat, sometimes high-carb, and less protein and fibre snacks. Which, of course, can lead to weight gain.
And, at least one study shows that eating at night increases the time it takes (healthy people) to fall asleep. Especially for women. So there is a bit of a “vicious cycle” in play here.
LACK OF SLEEP MESSES WITH YOUR HUNGER HORMONES
Many people who sleep less tend to eat more calories throughout the day. And not only due to increased time available for snacking, but also because of how lack of sleep can mess with the hormones that control both hunger and appetite.
How does this happen?
This is a “double-whammy” because some studies show that lack of sleep not only increases the stomach’s hunger hormone “ghrelin” (making you hungrier), but it also decreases the fat tissue’s fullness hormone “leptin” (making you feel less full).
These changes can clearly lead to more eating, and eventually weight gain or even obesity.
It’s possible that this is a natural mechanism that our body uses to make sure we get enough food for longer waking times. But this doesn’t always serve us well, as it tends to make us “overshoot” our energy needs and take in a bit more than we actually need.
LACK OF SLEEP MAY SLOW YOUR METABOLISM
Research is just emerging on this topic, but it seems to show that sleep deprivation can lower your “energy expenditure” and body temperature?
This means that your body may naturally burn less fuel at rest during the days when you’re sleep deprived.
When you burn less, you store more.
LACK OF SLEEP REDUCES EXERCISE
You know how tired you feel after not getting enough sleep?
This is the fourth way that lack of sleep affects weight.
By increasing fatigue, sleep deprivation can reduce the motivation to exercise.
And when you’re burning less fuel at rest (slower metabolism), and less likely to exercise, you’re at risk of gaining weight.
WANT TO KNOW THE GREAT NEWS?
Lack of sleep is considered a “modifiable risk factor”.
This means that, although it increases our risk for obesity, we have some power over it.
How well you sleep and how much sleep you get is something that you can improve by putting into place some tips and making them regular habits.
Download the 10 Tips for Getting Better Sleep so you can start implementing some strategies for a good night's rest today!
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