Tips & Advice

From Dr. Liz Herself

June 28, 2018
Sleep helps you lose weight
Cute Dog Sleeping

Why didn’t I become a school teacher?

My friend Sue is making wonderful plans for her summer break from her job as a special needs teacher for our public school district. I’m jealous.

OK, even though I don’t get several weeks off every summer, it does take pressure off my schedule that my son is out of school (it helps even more that he is away at camp for 6 weeks in Pennsylvania). Just that extra half hour of sleep in the morning makes such a difference.

In my patients working on weight loss, I see the difference enough sleep makes.

Why does getting enough sleep make such a big difference in our ability to reach and maintain a healthy weight?

The connection between higher body weight and lack of sleep has been observed for a long time in many scientific studies, but only recently have the reasons been better explained.

A 2010 overview of sleep and metabolism in the International Journal of Endocrinology starts off by telling us that a century ago, adults slept an average of 9 hours per night, as compared to 6.8 hours per night now (almost a third of adults report sleeping less than 6 hours per night).1

What are your hormones doing while you sleep?

During a night of sleep, the descent into a deep sleep in the first half of the night is normally accompanied by a rise in growth hormone and a drop in cortisol. Both of these shifts help regulate sugar levels in the blood and sugar used by the cells.

Evening stress and a late bedtime contribute to higher than normal cortisol levels when we go to sleep. Also, when we are tired from lack of sleep, our bodies make more cortisol to help us push through and do all of our daily activities (this happens after even one night of sleep deprivation2). This harmful cycle makes excess cortisol which then mobilizes the release of sugar, contributes to weight gain, and also turns around again and further disrupts sleep.

Growth hormone is mainly released in the first half of your night’s sleep, during the deepest stages of sleep3. Production of growth hormone drops after we are done growing then drops even more in our 30’s. This makes the loss of sleep have an even bigger impact (on skin, brain, metabolism, muscle strength, and much more) after age 40.

Melatonin is a hormone released by the brain starting in the evening of our daily circadian rhythm, enhanced by lower light entering our eyes. Normal release of melatonin continues throughout the night until light again goes through our eyes to the brain in the morning.

How are the hunger/appetite hormones affected by sleep?

A 2004 study published in the Public Library of Science (PLoS) journal4 showed that people getting less than 8 hours of sleep had the following:

  • Higher levels of ghrelin (the stomach hormone that turns on appetite), and
  • Lower levels of leptin (the hormone made by fat cells that turn off appetite)

Lack of sleep has also been shown to reduce cell response to insulin (in other words a kind of insulin resistance, like in acquired diabetes).

If all this is not enough, sleep deprivation also interferes with immune function and increases inflammation.

Melatonin – a natural supplement to help sleep 


Melatonin, although a hormone, is sold over-the-counter and regulated as a supplement, not a prescription drug. There is good data to support its use to correct jet lag and to normalize sleep rhythms in shift workers (whose sleep might be day or night depending on their schedule).5

Because of its high level of safety, and the fact that it is a naturally occurring hormone in the body, I recommend trying melatonin before going to prescription sleep medications.

Side effects from melatonin are unusual. I have sometimes heard from patients that they get very vivid dreams when using melatonin, which can be disturbing. My theory about this effect is that they are getting deep sleep for the first time in a long time and cycling through to REM (dream) sleep. Sometimes they can use a lower dose for a milder effect in order to get their sleep to improve over time.

Its effects can vary from person to person – some people respond well to very low doses (less than 1 mg) while other people need up to 10 mg or more to get an effect. If you have tried melatonin and it did not work well for you, try either a higher or even a lower dose.


There is so much information about all of these topics on the internet. My purpose here is to give you a brief overview of the hormones involved in sleep and how they affect metabolism and weight.

Even though you may not work for a school, if this summer is giving you any kind of break in your usual schedule, take advantage of the chance to get some more sleep, especially if you are working on your weight.

Please note: The material in these articles, provided by Dr. Liz Lyster, is designed to provide informative and current information as of the date of the posts. The articles should not be considered, nor are they intended to constitute medical advice. For information on your particular circumstances, please contact us.

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