Sleep on Wikipedia

Homeostatic sleep propensity (the need for sleep as a function of the amount of time elapsed since the last adequate sleep episode) must be balanced against the circadian element for satisfactory sleep.[42][43] Along with corresponding messages from the circadian clock, this tells the body it needs to sleep.


Important and biologically complicated

Sleep is important to a number of brain functions, including how nerve cells (neurons) communicate with each other. In fact, your brain and body stay remarkably active while you sleep. Recent findings suggest that sleep plays a housekeeping role that removes toxins in your brain that build up while you are awake.

Everyone needs sleep, but its biological purpose remains a mystery. Sleep affects almost every type of tissue and system in the body – from the brain, heart, and lungs to metabolism, immune function, mood, and disease resistance. Research shows that a chronic lack of sleep, or getting poor quality sleep, increases the risk of disorders including high blood pressure, cardiovascular disease, diabetes, depression, and obesity.


5 strategies to get better sleep

Deep sleep is when we experience accelerated muscle repair, and in children it’s the most important time for physical growth. Human Growth Hormone (HGH) is released into the bloodstream, which is good for muscle development and healing.


Want to lose weight?

Maybe more importantly than this, though, is the evidence cited in the letter relating to the impact of sleep on processes in the body that regulate appetite and therefore food intake. For example, short sleep is associated with higher levels of the appetite-stimulating hormone ghrelin and lower levels of the appetite-sating hormone leptin. Short sleep can also induce insulin resistance, and this might possibly impair transport of glucose into the brain and lead to increased hunger as a result.


Sleep and genetic obesity risk

Evidence is steadily accumulating that insufficient sleep increases the risk of obesity and undermines fat loss efforts. Short sleep duration is one of the most significant risk factors for obesity (1), and several potential mechanisms have been identified, including increased hunger, increased interest in calorie-dense highly palatable food, reduced drive to exercise, and alterations in hormones that influence appetite and body fatness. Dan Pardi presented his research at AHS13 showing that sleep restriction reduces willpower to make healthy choices about food.


Sleep a factor in rising diabetes rates

Perhaps not surprisingly, some researchers have suggested changing sleep patterns over recent decades might be an important but under-recognised factor in the burgeoning rates of obesity and chronic disease [10]. I’m inclined to agree with this, and believe that going chronically short on sleep is a potential hazard that many of us can do something about.


How artificial light is wrecking your sleep

So what’s causing this epidemic of sleep disruption in our country? Many experts feel that our excessive use of communications technology (e.g. cell phones, laptops, television, etc.) is driving this significant level of sleep deprivation. If this is the case, it’s no wonder so many Americans struggle with poor sleep, since 95% have reported using some type of electronics at least a few nights a week within the hour before bed. (7) Checking email, watching your favorite late-night comedian, or responding to a text message in bed seems harmless enough, but the sleep disruption caused by these light emitting devices is significant and potentially harmful to your health.


Light a double-edged sword for sleep

This ‘delaying’ effect on melatonin is not too much of a surprise, as previous research has produced similar findings. In one study, exposure to room lighting prior to bedtime delayed melatonin secretion by 90 minutes on average, and reduced the overall amount of melatonin too [9]. In another study, light from laptops and tablet devices was found to suppress melatonin too [10].