Lack Of Sleep Alters Hormones, Affects Weight

Sleep disorders are coming under closer scrutiny in a society plagued by their ubiquity, prompted by extraneous and self-induced pressures and obligations.  Discovery of the genetic basis for circadian rhythms has expanded our knowledge of the temporal role of behavior and physiology.  The relationship between sleep deprivation and hormone imbalance is publicized, but disregarded.  That part of the hypothalamus in charge of daily metabolic rhythm is called the suprachiasmatic nucleus, and it controls physical activity and hormone levels, as well as sleep, body temperature, immunity, and digestion.

Sleep deprivation, or even fragmentation, interrupts the machinery that controls energy expenditure and food intake.  A single night of sleep deprivation has been found to increase the risk of obesity by disturbing secretion and function of thyrotropin, cortisol and ghrelin (Benedict. 2011).  Thyrotropin is better known as TSH, the pituitary secretion that regulates the endocrine function of the thyroid gland.   Cortisol is excreted by the adrenal glands to address stress, affecting the metabolism of glucose, protein and fats. Ghrelin regulates appetite by telling you to eat, while its partner, leptin, tells you to stop.  Aberrations of these substances, aggravated by lack of sleep, reduce expenditure of energy during the waking hours.  Because fewer calories are burned, weight gain is almost certain.  Although the mechanisms behind it are not completely understood, “epidemiological evidence indicates that chronic sleep curtailment increases risk of developing obesity.” (Ibid.).

When we run low on energy from lack of sleep, many of us grab a coffee or three and a handful of junk to get a quick fix of comfort food.  That doesn’t last very long, though, does it?  Sleep affects one’s ability to maintain or to lose weight by regulating hormones and metabolism, which includes the way we handle food as part of the range of processes that occur within a living organism.  This entails anabolism (buildup) and catabolism (break down).  Deprivation of sleep is also tied to cardiovascular health and inflammation that is below the radar, called subclinical (Sharma. 2010).

We need about seven and a half hours of sleep each night.  An extra half hour, by the way, won’t help you to lose the last ten pounds.  But moving from five hours to eight might just be able to accomplish that.  It’s all in the hormones.  If you’re sleep-deprived, you have higher levels of ghrelin, telling you to eat.  That means that leptin is in short supply, and you’ll eat more than you need, ending up with more calories in and fewer calories out.  Oops, imbalance.

Apnea, bruxism (teeth grinding), narcolepsy, and insomnia are only a few of the sleep disorders that plague us.  Overcoming these insults can prevent the health conditions that stem from their upswing in modern society.  Besides obesity, impaired glucose tolerance and insulin resistance are real threats.  Losing some sleep for only a single night can upset the apple cart of insulin sensitivity (Donga. 2010).  That may be of significant relevance to a person harboring Type 2 diabetes, and most assuredly will be with Type 1.  What’s interesting is that voluntary sleep deprivation is a characteristic of modern life, where people put more stock into their jobs than into themselves and their families (Bosy-Westphal. 2008).  Here, weight gain from increased energy intake is earned, even without conscious thought.  Once the inborn clock gets out of whack, don’t be surprised by physiological dysregulation of one kind or another (Huang. 2011).

Sleeping as little as possible is not admirable behavior.  High-schoolers and students cramming for college exams are not doing themselves any favors.  Neither is the mom or dad who works into the wee hours, a common activity in industrialized nations.  Since the 90’s, researchers have paralleled sleep deprivation with the rise of obesity, especially in kids (Leproult. 2010) (Knutson. 2008).  Since our hormones vary from day to night, it matters that we keep circadian rhythm aligned with the design of their function.  Shut off the TV and get rid of the computer games at bedtime.  Put the cell phone away while you’re at it.

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