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Obesity Linked to Poor Sleep
Poor sleep and obesity are like two peas in a pod. If you don't sleep well, your chances of becoming overweight or obese become greater.
This is the finding of research that has studied sleep habits together with relative weight and waist circumference among different populations.
The most recent study comes from the College of Medicine at Korea University, where researchers conducted a nationwide study that included 9,077 adults.
The research surveyed the participants and correlated the number of hours they slept a night together with their body mass index (BMI).
The participants were divided into four categories that related both their weight and whether they had symptoms of metabolic disease – which include cardiovascular disease and diabetes. The calculated results also eliminated the effects of drinking, age, smoking and others.
On the criteria of obesity alone, the researchers found that those who were obese slept on average 0.15 of an hour less than those who were not obese. And when their metabolic classifications were considered, those who were obese slept a cumulated average of 0.20 of an hour less than the normal weight participants.
Many Other Studies Confirm This Association Between Obesity And Sleep
This relationship of obesity and sleep duration is not limited to this study. Recently, a large meta-study published in the journal Sleep analyzed the results of 21 studies that included 56,259 people.
The studies compared sleep duration with waist circumference – a more direct variable to obesity.
The researchers found that the lower the sleep duration, the higher the waist circumference. The relationship was rated as significant to a factor that would have required 418 studies with no results to negate the relationship between the two.
That means the relationship is pretty solid. Poor sleep relates directly to obesity.
What About Oversleeping?
One might wonder why I am saying "poor sleep" rather than simply "less sleep."
The reason is because other research has shown that long sleep duration is also associated with obesity.
This was determined in a study from Harvard Medical School in 2010. The researchers analyzed data from the 2004-2005 U.S. National Health Interview Survey, which included 56,507 adults between the ages of 18 and 85 years old.
The research found that both short and long sleep duration was related to obesity, as well as diabetes and cardiovascular disease. They found that both less than seven hours and greater than eight hours were both linked to a greater risk, and that between seven and eight hours presented the least amount of risk in the greater population.
This study found – as have others – that not getting enough sleep increases risk of obesity greater than oversleeping. But oversleeping still increases risk.
This relationship also means that the studies above are minimizing the negative effect of not getting enough sleep – because the negative effects of getting too much sleep are also included in the same statistics.
The Key Factor is Oxidative Stress
The metabolic reasons for lack of sleep and too much sleep increasing the risk of obesity seem counter-intuitive but they are real. The reality is that our body works hard and smart when we are sleeping. Up to a point.
But the weight loss isn't because the body is working hard – because certainly our body uses up more calories when we are awake and running around than when we are sleeping.
The issue is that while we are sleeping, the body's cells and probiotics work together to detoxify the tissues and remove pathogens that interfere with health. This detoxification process is healthy because it leaves the body with less oxidative stress.
Oxidative stress is associated with weight gain because our bodies become more inflammatory with greater oxidative stress. Oxidative stress results in greater adipose tissue consolidation through the relationship between oxidation and inflammation.
This reality was documented by researchers from Italy's University of Messina, who wrote:
"Based on the complex interplay between adipokines, obesity is also characterized by chronic low grade inflammation with permanently increased oxidative stress."
So what about sleeping longer – or oversleeping? The research is clear that this also increases the risk of inflammatory diseases as well as obesity as mentioned above.
But during oversleeping the process is a bit different. The body finds itself in a condition where its normal adrenal processes are stifled through under-activity. Once the body gets enough sleep for cell repair and detoxification, additional sleep depresses the body's natural production of important adrenal products such as glucocorticoids and cortisol. This lack of production depresses the normal energy production of the cells, which then allow greater levels of oxidation.
Nature, we find, is finely tuned. Just as Goldilocks had to find the right fit among the bear's beds and bowls, each of us must find the right amount of hours sleep that fits our body's needs for regeneration and detoxification - without overdoing it.
Because as we all know, too much of a good thing is usually not so good.
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