10 December 2014

VISIONS OF SUGARPLUMS || Why insomnia and sleep deprivation cause cravings

The science has been out for a while on this topic, but it's always good to raise the issue of sleep loss as it relates to weight gain. There is definitely a yin-yang element balancing our metabolism with our ability to achieve quality sleep, night after night.

First, some clarifications of terms:

Insomnia is the inability to fall asleep or to maintain sleep over many nights. It can have many causes: behavioral, physiological, pharmaceutical, environmental.

Sleep deprivation is the result of not getting adequate sleep night after night, either due to insomnia or other health condition, or to some self-imposed behavior (going to bed late then getting up early, perhaps, or working the overnight shift and not getting good recovery sleep).

If you suffer from one or both of these situations, you are setting yourself up for the possibility of slower metabolism and unwanted weight gain over time. Here's a few reasons why.

"Voodoo Doughnut Documentary Project" (2005)
by Anna Maj Michelson. CCA:2.0-Generic.
Studies show that sleep deprivation influences the primal region in the brain which controls decisions, especially when they involve rewards. In addition, our usually logical, more sensible executive functions are blunted by inadequate sleep and fail to override bad decisions about things like eating. It's a lose-lose situation, if we are sleep deprived, we are more inclined to crave unhealthy food and have little willpower to make good choices. If offered apples, carrots or strawberries, we will still likely abandon these healthier choices for pizza, doughnuts and hamburgers if given the opportunity.

Other studies have shown that chemical processes that take place in those with inadequate sleep generally create a hormonal imbalance that "informs" your cravings in the less healthy direction. Fat cells release the hormone leptin into the bloodstream to signal the appetite has been satiated. When the body is hungry, the same fat cells release the hormone ghrelin into the bloodstream to signal that is time to eat. When one is sleep deprived, there's often less leptin in the bloodstream and too much ghrelin in the bloodstream, and this is what leads to cravings: the brain is convinced you are starving because of this hormonal imbalance in the bloodstream.

Put these two elements of sleep physiology together and you can see where you might be headed if you don't keep up a decent sleep schedule. If you have just one night of insomnia or you have to shave off a couple of hours of sleep every once in a while due to work or travel, it's not going to turn into a downward obesity spiral, but if you have chronic problems with poor or inadequate sleep, you may find yourself packing on the weight and finding it difficult to stave off cravings. And then the vicious cycle begins: overweight bodies are overtired, while often underexercised and deprived of sleep, simultaneously.

National Geographic recently ran some eye-opening surveys about sleep in America, confirming what scientific evidence has been saying for a while now: the less that you sleep, the more weight you are likely to gain, as much as almost 8 times more than those who sleep close to 8 hours every night. This, even after accounting for exercise habits and family history.

The takeaway is this: Want to be healthy? Want to avoid obesity? Get your ZZZs.

Resources

Insomnia Increases Junk Food Cravings: Sleep deprivation blunts brain function linked to eating healthy foods || Psychology Today--The Athlete's Way

Body Weight and Sleep || Sleepdex

The State of Sleep Deprivation in America || National Geographic Channel