Saturday, August 16, 2014



Evidence against the warrior diet being conducive to normal human circadian rhythm optimization

Based on the physiology of the light entrainable oscillator (LEO) of the suprachiasmic nucleus (SCN) of the human brain, we are night time sleepers.  During the day, sunlight entering our eyes causes a decrease of melatonin production in our brains.  Melatonin is a chemical that promotes sleepiness, so when it is low during the day we are more alert and awake.  During the dark hours, melatonin increases in our brains and we get sleepier.  

Another effect of a normal circadian cycle is core body temperature (CBT) oscillation.  CBT peaks during the day and troughs during the night.  The bigger the amplitude of CBT the higher the sleep quality is.  The architecture of higher quality sleep includes higher percentages of slow wave sleep (SWS) and rapid eye movement (REM) sleep. 
There is a food entrainable oscillator (FEO) in the peripheral tissues of the body as well.  The intake of food is the zietgeber or time giver for the FEO, and the FEO can be in synchrony with the LEO, or it can be out of synch depending on the timing of said food intake.  

The effects on sleep of asynchrony between the LEO and FEO were illustrated in a study titled “Sleep during Ramadan intermittent fasting” by Roky et al.  In the study, they observed a decrease in sleep quality and CBT amplitudes of the subjects during the night time only eating period of Ramadan.  Night time eating interfered with night time sleeping.  

Another study titled “Alterations of internal circadian phase relationships after morning versus evening carbohydrate rich meals in humans” by Krauchi et al, observed that the evening carb rich meal caused a significant decrease of the CBT amplitude resulting primarily from an increased night time trough.  That means poorer sleep after the evening meal.  

Another study, more pertinent to the warrior diet’s central premise concerning the autonomic nervous system, is titled “Effect of insulin and glucose infusions on sympathetic nervous system activity in normal man”.  In it, Rowe et al show evidence that increased plasma insulin causes an increase in SNS activity.  Eating carbohydrates causes an increase in plasma insulin which causes an increase in SNS activity, whereas, fasting and carbohydrate restriction stimulates parasympathetic nervous system activity via a reduction of plasma insulin.  This is the opposite of warrior diet theology.  

So, eating a majority of one’s calories at night before bed time is antagonistic to night time sleep quality and optimal circadian rhythms.  

Why should anyone care?  Circadian rhythm disruption is associated with a host of diseases of civilization including cancer and cardiovascular disease, the two leading causes of mortality and morbidity in the U.S. 

With all of this in mind, I believe that eating during a morning restricted feeding window is best for circadian rhythm optimization.  

I believe God speaks to us through the results of science too.  

Those who have eyes will see.  Those who have ears will hear...  

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