There are a few basic actions that if most people were to incorporate into their lives would promote good health and well-being. These include eating a healthy diet, maintaining a healthy weight, and getting enough sleep at night. However, sadly, the latter often falls by the wayside.
This lack of sleep may be more impactful on our health than we once thought, especially in our children. A new study from researchers at the University of Pittsburgh School of Medicine Department of Psychiatry and the Western Psychiatric Institute and Clinic of the University of Pittsburgh Medical Center finds that children and teens that spend less time in the rapid eye movement (REM) phase of sleep are more likely to be overweight.
In the past 30 years, the obesity rate in America has skyrocketed to the point where approximately 17 percent of U.S. adolescents are now overweight or obese. Much of this is thought to be the result of increased calorie intake and fewer calorie expenditures – essentially eating more and exercising less.
However, there may be other factors such as a lack of quality sleep that may be to blame for this imbalance.
We sleep in several phases
The rapid eye movement (REM) phase of sleep is often regarded as one of the most important. As the name suggests, your eyes rapidly dart back and forth under the eyelids during this phase, and sleep studies have concluded that this REM phase helps to restore the mind and body from the stressors of the day prior. This is also the part of sleep where dreaming occurs.
There are several stages of sleep that occur once we close our eyes and progress cyclically to REM, then begin again.
They are as follows:
- Stage 1: Light sleep, where we are awakened easily. Our eyes move slowly and muscle activity slows. Alpha waves are seen when observing brain activity.
- Stage 2: Our eye movement’s stop and our brain waves become slower with occasional rapid bursts. Heart rate slows down and body temperature begins to drop. This stage is meant to prepare us for deep sleep. Rhythmic brain wave activity known as theta waves and sleep spindles are seen.
- Stage 3 and 4: Known as slow wave sleep. Blood pressure falls, breathing slows, and the body becomes immobile. It is most difficult to be awoken from this stage, with most people feeling groggy and disoriented when they wake up during these phases. Delta waves are seen in brain activity.
- REM – rapid eye movement: This phase dominates the latter portions of sleep and increases in duration as the night progresses. The brain is seen to be the most active during this time, very similar to when being awake. Low amplitude mixed-frequency brain waves consisting of theta, alpha, and beta waves are seen.
Several previously done studies have found an association between fewer hours of sleep and higher body mass index
(BMI) in both adults and children.
Looking at the sleep patterns of hundreds of children
The study in question evaluated over 300 children and adolescents between the ages of seven and 17. Each was monitored via polysomnography (a test to study sleep) for three nights in a row. Parameters such as total sleep time, time to fall asleep, and time spent in REM were measured, among others.
Of the children tested, 14.6 percent of participants were at risk for becoming overweight and another 13.4 percent were overweight, at the start of the study.
It was found that overweight children slept 22 minutes less per night, had shorter REM sleep, less eye activity during REM, took longer to reach the REM phase, and spent less time in bed sleeping overall when compared to children of normal weight.
The researchers concluded that losing even one hour of total sleep was associated with a two-fold increase in odds of being overweight, with the loss of one hour of REM sleep associated with a three-fold increased risk.
It is believed that sleep deprivation may be leading to behavioral and biological changes, the researchers say. Hormones that regulate hunger may be affected by sleep loss. Additionally, sleep loss may contribute to fatigue, decreasing physical activity and calorie burn.
Related: Why it’s important to get a good night’s sleep