Sleep and overweight - a wider relation than expected?

 Sleep, an interesting subject, which the science havent fully explored yet.
Some days ago this subject where brought up at treningsforum.no, and I think it's an important subject to bring out to you! - You can read the whole article in norwegian HERE.

For my international readers, I will summarize the key elements from it in this post.


There is an increasing amount in research about sleep, and that sleep has an central effect to our appetite and food consumption. (also written about earlier HERE, "Can lack of sleep lead to overweight?"(norwegian article))
In this post there will be explained closer about what's known about sleep, what it's important for, and how sleep regulates the two most important appetite hormons, ghrelin and leptin.


What is sleep?
Sleep is a active process, that includes inhibition of nerve fibers conducting pain, and stimulation of nerve fibers who secrets the sleep producing neurotransmitter serotonin.


Sleep, and its functions
This is not fully explored yet.
But of experience in periods with lack of sleep, you know this decreases:
- the cognitive functions
- productivity
- concentration
- physical performance.
Sleep does probably play a role in the maintenance of body functions, development of the nervous system and the ability to learn.


Development of sleeping patterns
Our sleeping pattern has a background in the cyclus of light/darkness.
Disturbances (artificial lightning, increased activity in the evening) disturbes the biological rhythm  and decreases the sleep quality.
Including this, the access of energy-dense foor has increased over the past years, and a bader sleep quality is associated with the explosive increase in bodyweight.

On this basis, sleep is associated with overweight and metabolic syndrom trough the following mechanisms:
1) Increased/up-regulation of appetite
2) Energybalance


Increased/ up-regulation of appetite
Back to the appetite regulating hormones Leptin and Ghrelin.

Leptin - satiety hormone (high levels = satiety, Low levels = hunger)
Gherlin - functions opposite (high levels = hunger, Low level = satiety)

Van Cauter and Knutson,2008 - a systematic review, shows result from studies exploring the Leptin-response after a variable amount of hours sleep.

Comparing 12 hours of sleep with 4 hours, the Leptin-levels where 19% lower in the population sleeping 4hours. (=increased feeling of hunger)

Another highlight, was that the glucose-tolerance was reduced with 40%(!!) including a lower insulinesensitivity by lack of sleep.

Low Leptin-Levels + reduced insulin-sensitivity = the appetite increases with less hours of sleep!

Further on there are in total 23 different studies reporting this facts. In total of 28 studies, only 4 studies did not find the same relations.

Energybalance

Lack of sleep can be associated with a lower energy consumption, because of earlier fatigue/tiredness, lowering of trainingvolum/activity, and more time in front of the television (wich is associated with snacking).

Less sleep, also gives you more time for eating.

So if we adds the increased appetite to this, there is easy to end up with a energy-surplus over time resulting in increased weight.

Chaput et al, 2010 - gives an good schematic overview in how lack of sleep can lead to increased weight.

Further on:

An increasing amount of studies points out that sleep doesn't only play a role, but are maybe the most important role when it comes to overweight in children (Chaput et al. 2006)
Epidemiological data - indicates that lack of sleep is associated with diabetes type 2 (Yaggi et al. 2006), coronary artery disease (King et al. 2008), high blood pressure (Gangswich et al. 2006) and death (tamakoshi and Ohno. 2004)

BUT - do not worry! In the fight agains overweight and lifestyle diseases, does it seem like we have another weapon in position - something we have in our control, and something to lead us in the right direction --> namely : Sleep!

To find more articles like this - visit treningsforum.no.

Knowledge is power!! ;)

How many hours do you sleep every night?

My goal is 8hours quality sleep every night, and never under 7 and a half!




BTW! I'm feeling allot better after the day of, yesterday! Allot of sleep and relaxation was good and needed for the body!! Today - I'm having my scheduled day of - so now I'm soon going insane!! (or I maybe already did!!) So good there will be workout tomorrow!!

This is the results of two days with no training!!

Hope you had a nice week so far! Soon it's the weekend, and time for som relaxation of sleeping ;) (If you don't have an exam on monday of course!)

Wish me good luck!

Hopefully things will go well, and my lack-of-training-induced-insanity will disappear soon!!

Chaoo! ;)