Sleep & Body Composition

By: Yvette Styner, DYNAMIS Athlete 

Being sleep deprived doesn’t just make you tired and sluggish, it may make you fat! 

While scientists aren’t sure how it all works yet, there have been many irrefutable studies and ample evidence showing that not getting enough sleep leads to long term metabolic and hormonal consequences.   In addition to the fact that restorative functions such as muscle repair and growth occur while we sleep, sleep restriction also decreases energy levels, increases appetite, results in weight gain, impaired hormonal balances, and may cause insulin resistance…  It is a vicious cycle.

Being tired and having low energy creates more feelings of hunger, leading to overeating. 

How often are you tired and find yourself craving high carb and sugary foods that you otherwise wouldn’t desire?  It seems to be a natural body response that when we are fatigued and our bodies are in need of energy, we will crave these quick sources of food energy found in refined sugars and hi carb foods.  It’s not just cravings or lack of will power, the science is this:  Leptin and ghrelin are two hormones that regulate appetite control.  Leptin is an appetite suppressant produced by adipose tissue and ghrelin is released from the stomach primarily in response to fasting (sleeping is by definition a fast) and promotes the feeling of hunger.   These two work in unison to help our bodies cope with the fasting period (and ensuing changes in glocuse & insulin levels) while we sleep.  If sleep is disrupted, so are these processes and appetite will be affected.

Less sleep = less exercise due to being low energy.  Less exercise leads to a lower metabolism and furthers leads to weight gain.

Lack of sleep can do serious damage to cells throughout the body by causing insulin resistance.

Current data shows troubling evidence of direct correlation between sleep, and diabetes and obesity as a result of insulin resistance due to alterations in glucose metabolism.  After we eat, our food is broken down into sugars.  The main sugar is called glucose and passes through our gut wall into our bloodstream as fuel for our cells.  To remain healthy, our blood glucose level should not go too high or too low.  As it begins to rise after eating, our pancreas releases the hormone insulin.  It goes to the cells of our muscle and fatty tissue and signals them to take in the glucose to use for energy.  When our glucose begins to fall (between meals) the level of insulin falls as well.   If you become insulin resistant, insulin doesn’t bind to the cells, which means it doesn’t move the glucose into the cells.  “Glucose is locked out.  High levels of glucose keep circulating in the blood causing all sorts of problems”.   Many factors cause insulin resistance, including being overweight, inactivity, poor diet, and yes - insufficient sleep.  (*1)   Inadequate sleep disrupts the balance of glucose tolerance and insulin sensitivity, not only during the sleep period in question, but on an ongoing basis.   Among numerous case studies on the long term effects of sleep, one such experiment was conducted in which researchers determined that after 4 days of sleep restriction, the subjects were 30% less insulin sensitive; the ability of all tissues to use insulin properly.  *(2)  If your body is not using insulin properly, you may experience brain fogginess, high blood sugar, intestinal bloating, sleepiness after meals, weight gain, fat storage, difficulty losing weight, increased blood pressure, depression and increased hunger.

The chart below demonstrates the relationship between sleep restriction and weight gain and ultimately diabetes risk as discussed: upregulation of appetite, decreased energy expenditure, and alterations in glucose metabolism.    *(3)

Other Factors:

TSH:  If that’s not enough, even partial sleep deprivation (3-5 days) has also been shown to greatly depress thyroid stimulating hormone (TSH).    “TSH stimulates the thyroid gland to secrete the hormone thyroxine (T4), which has a slight effect on metabolism. T4 is then converted to triiodothyronine (T3), which is the active hormone that stimulates metabolism.”   *(4)

Kills sex drive:  Sleep specialists say that sleep-deprived men and women report lower libidos and less interest in sex. Depleted energy, sleepiness, and increased tension may be largely to blame.  *(5)

Growth Hormone: Growth hormone is normally released during sleep. If someone consistently gets too little sleep growth hormone is suppressed.

Cortisol:  Cortisol can be discussed in length in a whole separate article!   Among its many diverse roles in our physiology, it plays an important role in the breaking down of glycogen.  It’s also a stress hormone and is released in response to a stress, sparing available glucose for the brain, generating new energy from stored reserves, and diverting energy from low-priority activities (such as the immune system) in order to survive immediate threats or prepare for the exertion of rising to a new day.  Increased prolonged stress (even low-level stress) increases our cortisol levels.  Prolonged cortisol secretion results in significant physiological changes.  *(6)

Cortisol also raises the free amino acids in the serum. It does this by inhibiting collagen formation, decreasing amino acid uptake by muscle, and inhibiting protein synthesis.  Increased cortisol levels also result in increased appetite despite ample food intake, leading once again, to weight gain.    Sleep loss has been found to affect the resiliency of the stress response, thereby increasing our cortisol levels.

Get some sleep!

  • Have a pre-sleep routine; establish and stick to a bed-time regiment.
  • Sleep in a cool location, as dark as possible.
  • Avoid large meals, caffeine and alcohol close to bedtime (watch for “What to Eat before bed to Optimize your Metabolism” article on Dynamis blog coming soon)
  • Practice relaxation techniques, try herbal teas.
  • Take HARMONIX 11Hz before bed.  Relaxes the body and mind, decreases cortisol levels, boosts growth hormone production, maintains optimal muscle function, offsets the effects of caffeine, and it’s enhanced with vitamin D for muscle growth.
Sweet Dreams!
- Yvette Styner, Natural Figure Athlete, DYNAMIS Sponsored Athlete



(2)  Broussard, J.L., Ehrmann, D.A., Van Cauter, E., Tasali, E., Brady, M.J. Impaired insulin signaling in human adipocytes after experimental sleep restrictions. Ann Intern Med 157(8): 549-557, October 16, 2012.