Poor sleep doesn’t just affect the mind, it reshapes how the body manages hunger, cravings, and digestion. In this NightOwling lesson, circadian health expert and medical scientist Logan Pendergrast, Ph.D., explores the connection between disrupted rest and the gut.
This lesson examines how sleepless nights can alter communication between the brain and the microbiome, shifting appetite signals and metabolic balance. Dr. Pendergrast explains how these changes can influence food choices, inflammation, and long-term energy regulation.
Learn how the quality of your sleep shapes the way your body processes food and why restoring that balance begins long before your next meal.
     
 
            
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So, moving from the brain into talking
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about the stomach, we're going to begin
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to talk now about how our gut is
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affected by poor sleep. Now, despite the
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fact that these areas of the body are so
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far away from one another, they're in
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constant communication. And we can see
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this when we look at what happens after
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a night of poor sleep. Poor sleep leads
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to an effect on the body's microbiome,
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particularly the gut's microbiome. And
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what this does is it causes a increase
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in inflammation and an increase in
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cravings. Now, it's not just the
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microbiome that's responsible for this
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increase in cravings. We see that after
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a night of poor sleep, there is an
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increase in the release of a hormone
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that's released in the stomach called
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grelin. And that hormone is responsible
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for hunger. It's responsible for the
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feelings of hunger pangs. And
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additionally we see that after a night
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of poor sleep there is a decrease in the
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amount of release of a hormone called
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leptin. And this hormone called leptin
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is released from our fat cells and it
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makes us feel full. So we see an
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elevated level of grelin which makes us
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feel hungry and a decreased amount of
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leptin which makes us feel full. So the
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combination of these two factors is
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responsible for driving individuals
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towards elevated levels of weight gain
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when they experience constant levels of
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poor sleep. And we see these effects
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actually measured in the uh scientific
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literature where one night of poor sleep
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increases levels of grein by 28% and
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decreases levels of leptin by 18%. which
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is causing this perfect storm of seeking
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to eat foods, junk foods, and elevated
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levels of calories when we're not
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sleeping properly.