We know that a good night’s sleep isn’t always as easy as it is made out to be. No matter how many new routines, sleep hacks and relaxation techniques you try in the hours leading up to bedtime, sometimes it’s the very stress and anxiety you’re trying to counter by going to sleep early that can stop you from nodding off, leaving you lying awake very late in the night until you have to wake up. No wonder we spend about one-third of our lives sleeping. A lot is still unknown about the purpose of sleep.
However, it’s widely accepted that there isn’t just one explanation for why we need to sleep. It’s likely necessary for many biological reasons. To date, scientists have found that sleep helps the body in several ways. We sleep to conserve our energy. Sleeping allows us to reduce our caloric needs by spending part of our time functioning at a lower metabolism. This concept is backed by the way our metabolic rate drops during sleep. Research suggests that 8 hours of sleep for human beings can produce a daily energy savings of 35%.
Sleep affects many aspects of brain function, which includes learning, memory, problem-solving skills, creativity, decision making, focus and concentration. Similarly, sleep is necessary for emotional health. During sleep, brain activity increases in areas that regulate emotion, thereby supporting healthy brain function and emotional stability. Research shows that sleep and mental health are intertwined. On the one hand, sleep disturbances can contribute to the onset and progression of mental health issues, but on the other hand, mental health issues can also contribute to sleep disturbances.
Sleep affects your weight by controlling hunger hormones. These hormones include ghrelin, which increases appetite, and leptin, which increases the feeling of being full after eating. During sleep, ghrelin decreases because you’re using less energy than when you’re awake. Lack of sleep, however, elevates ghrelin and suppresses leptin. This imbalance makes you hungrier, which may increase the risk of eating more calories and gaining weight.
Recent research shows that chronic sleep deprivation, even as few as five consecutive nights of short sleep, may be associated with increased risk of obesity, metabolic syndrome, type 2 diabetes.
Insulin is a hormone that helps your cells use glucose, or sugar, for energy. But in insulin resistance, your cells don’t respond properly to insulin. This can lead to high blood glucose levels and, eventually, type 2 diabetes. Sleep may protect against insulin resistance. It keeps your cells healthy so they can easily take up glucose. The brain also uses less glucose during sleep, which helps the body regulate overall blood glucose.
What happens if you don’t get enough sleep?
Without enough sleep, your body has a hard time functioning properly. Sleep deficiency is linked to chronic health problems affecting the heart, kidneys, blood, brain, and mental health. Lack of sleep is also associated with an increased risk of injury for both adults and children. In older adults, poor sleep is associated with an increased risk of falls and broken bones. Specific consequences can include mood changes, anxiety, depression, poor memory, poor focus and concentration, fatigue, weakened immune system, weight gain, high blood pressure, chronic diseases, like diabetes and heart disease, increased risk of early death.
