Sleep is critical to so many areas of our lives. In this series of posts I'm sharing all the ways that sleep can benefit your mind, body, and spirit.
Today we're looking at how sleep affects your body.
Better sleep = better life.
Sleep deprivation, both acute (one night) and chronic (long-term), causes many bad outcomes that are strongly tied to obesity and poor muscle development.
Sleep deprivation encourages adverse weight gain, and is bad for body composition - your ratio of muscle to body fat. A lack of sleep increases your risk of gaining up to 5kg by 35%, and increases your risk of obesity by 27% (compared to people with optimal sleep patterns).
Sleep deprivation can derail your body composition efforts in four different ways.
#1 - It messes with your hormones
Multiple studies have shown that people who sleep five hours or less per night have higher levels of ghrelin (the hormone that stimulates hunger), and lower levels of leptin (the hormone that suppresses appetite) compared with people who sleep eight hours a night.
#2 - It messes with your DNA
Sleep loss causes molecular changes deep inside our tissues, which predispose a person to negative body composition outcomes of increased fat storage and decreased muscle mass.
Sleep loss can have “double-whammy” effect on cell metabolism and the regulation of gene expression.
Sleep researchers see specific molecular signatures following sleep loss, indicating that fat tissue is attempting to increase its capacity to store fat. Meanwhile muscle tissue goes in the other direction – researchers see a breakdown of skeletal muscle proteins (known as catabolism).
#3 - It messes with your brain chemistry
Some of the mind-altering effects that I discussed in part one of this series can lead directly to body-altering outcomes.
Brain imaging studies have revealed up-regulated neural pathways for food rewards in the brain’s reward-processing areas, following sleep loss. Ghrelin (the appetite stimulating hormone) is also increased in sleep-deprived groups compared to the control groups who got sufficient sleep.
In simulated exercises of food and economic exchange, the sleep-deprived group was willing to spend more money on food items in the decision-making task. The subjects’ brain activity was recorded while they performed these task, and the researchers saw an upregulation of certain signals in the amygdala and hypothalamus which are specific to food rewards.
This shows that sleep deprivation increases our perception of food value, deep in the wiring of our brains. And this was obvious after just one single night of sleep deprivation.
#4 - It messes with your gut microbiome
There is a strong link between sleep and your gut health, and it seems to be a two-way street:
The health and diversity of the bacteria living in your gut can affect the quality of your sleep, while your sleep and circadian rhythms appear to affect the microbiota in your gut.
Sleep loss has been shown to alter gut microbiota in ways that predispose you to obesity.
Sleep deprivation causes:
- A marked decrease in beneficial types of bacteria
- Changes to the composition of certain micro-organisms in the microbiome that are specifically linked to obesity and type 2 diabetes
- A significant decrease (read: worsening) in insulin sensitivity
On top of all that, if you try to diet to overcome these effects, you’ll derail your own efforts unless you’re getting enough sleep. Those changes in gene expression that I mentioned earlier will work against you, ensuring that up to 70% of any weight you lose comes from lean body mass (e.g. muscle), rather than body fat. And that's definitely not what you're looking for.
Wait, there's more?
Sleep loss has even more tricks up its sleeve, contributing to these adverse effects:
- It worsens athletic performance
- It increases insulin resistance, glucose tolerance, and risk of Type 2 Diabetes
- Your immune function is compromised
- It causes inflammation
- It encourages osteoporosis
- It causes stomach ulcers
- It causes poor skin quality
Wrapping up
It's easy to see just how important sleep is for our physical well-being, as well as our mental performance. Lack of sleep can affect us in so many ways, and yet the vast majority of us simply aren't getting enough sleep.
Sleep is a skill just like any other. And just like any skill it can be learnt, practiced, and mastered.
Your virtual sleep coach,
Todd
