The Relationship Between Sleep, Hormones, and Weight Gain

By Teresa Wagner RD, LD

When we aren’t getting enough sleep, we are affected much more than just how tired we feel the next day. It sets off a hormonal cascade that can influence the number on the scale and over time can lead to significant weight gain and chronic illnesses. How much sleep is “enough”? For adults, the recommendation is to get seven and a half to nine hours per night most nights.

How Sleep Affects Appetite
So, what happens when you aren’t getting your sweet spot of hours slept? Let’s start with appetite.  To put it frankly, when you are not getting your energy restored from sleep, you will likely look for energy from food. And I’m not talking about cravings for steak and broccoli! More likely you’ll be feeling a deep desire for quick energy, which you may look for in high sugar and processed foods or drinks. It’s also likely that the amount it takes for you to hit your satisfaction point will increase. Let’s take a look at why that is:

There are 3 significant hormones that come into play: leptin, ghrelin and insulin.

• Leptin – the hormone of fullness and satiety
• Ghrelin – the hormone of hunger
• Insulin – the blood sugar regulator

As you may expect, when sleep deprived, ghrelin goes up (increased hunger) and leptin levels go down (less satiety).  When we don’t get enough sleep, our hormones shift, which makes us hungrier and it takes more food to feel full, a double whammy. 

Studies have shown that lack of sleep causes people to consistently overeat, usually somewhere between 250-400 calories per day. If that doesn’t sound like a lot to you, consider that the average person burns about 100 calories per mile walking or jogging. To work off that increased caloric intake that is associated with lack of sleep, we would need to increase our daily walks by 2.5-4 miles.

The same research showed that snacking becomes a problem in sleep deprivation too. After eating a large meal of approximately 1000 calories and then presented with an option to snack, those who had slept less than 8 hours consumed an additional 200-300 calories than those who had a full night’s sleep.

What We Crave When Tired
Now let’s talk about what we have an appetite for when we’re under slept and its effect on the blood sugar regulating hormone, insulin.

In another research study, when individuals were limited to 4-5 hours of sleep for several nights, they experienced a 33% increase in the desire to eat sugary foods, a 30% increase in desire for processed, high carbohydrate foods (like pasta and pizza), and a 45% increase in desire for salty snacks.

When we eat foods that fall into those categories, the body’s natural response is to release insulin to lower the corresponding high blood sugar that follows. Over time, consistently overconsuming high sugar/high carbohydrate foods can lead to insulin resistance.  When the body becomes insulin resistant, the utilization of blood sugar becomes impaired making it easy to gain weight and difficult to lose it.

In another study, healthy individuals who did not have a history of blood sugar dysregulation, had a significant increase in their fasting blood sugar when sleep deprived.  So significant was this increase that, had they been seeing their primary doctor rather than being involved in a research study, they would have been screened for pre-diabetes! Even partial sleep deprivation over one night has been shown to increase insulin resistance, which in turn increases blood sugar levels.

Tips For a Better Night’s Sleep
If you want to sleep but struggle with the ability to fall or stay asleep, before opting for pharmaceuticals, consider natural practices with lasting effectiveness without side effects or dependence. The best place to start is with good sleep hygiene, which includes your morning routine too!

Set your circadian rhythm in the morning:

• Start the day with 2-10 minutes of sunlight exposure within one hour of waking with no sunglasses, even on cloudy days. Melanopsin cells of the eyes have sensors which organize the timing of ALL your cellular processes. Photons from the sun trigger a pulse of the hormone cortisol and also sets a 16-hour timer for when the sleepy hormone, melatonin, will be released.
• Exercise in the morning helps to shift forward the circadian rhythm making you tired earlier by stimulating an earlier release of melatonin.
• Cold showers or cold-water rinse in the morning supports a natural boost in alertness, focus and energy due to increases in cortisol and norepinephrine. This is desirable as a rise in both hormones play a role in the wake part of the sleep-wake cycle and are helpful in getting us out of bed in the morning.   

Create a sleepy environment in the evening:

• Consider eliminating screens and dimming house lights within one hour of bedtime. Bright lights trigger the melanopsin cells interfering with the production and release of melatonin.
• Follow a schedule and have a bedtime routine - they’re not just for infants and toddlers. Ideally bedtimes and wake times should be similar every day of the week. Do the same activities every night 15-30 minutes before bed: wash face, brush & floss, non-screen reading, meditation, etc.
• Keep your bedroom cool and very dark. Research suggests ideal temperature for sleep is between 65 -69 degrees. Use blackout shades and cover all lights including power lights and clocks.
• Hot baths are great before bed because they lower core body temperature by increasing circulation to the extremities and away from the core. As we sleep, our core body temp drops almost 2°F from its highest point of the day. Ever get that shiver when you stay up past your bedtime? Melatonin release helps trigger the body’s cooling process.

Nutrition Can Help Too
Tried all of those options? Consider talking with a dietitian or nutritionist over at our sister company Nutritional Weight & Wellness who is trained in sleep. Types of food, timing of eating, blood sugar regulation, nutrient deficiencies (such as magnesium), can all play a role in how well you are able to fall and stay asleep.  Many dietitians are also trained in habit change. With lack of sleep, sometimes it’s an inability to actually sleep well and sometimes it’s more related to habits that can be tweaked to help you get more zzzz’s.

Here are a couple of nutrition-related tips to get you started:

• Eat in balance throughout the day. Just like the sleep hygiene tips where you can help set your circadian rhythms in the morning and not just the evening, you can help regulate your blood sugar and your hormones throughout the day – making it easier to keep them balanced at night for sleeping. A nutritionist or dietitian can help you find the right plan for you, but a good place to start is eating animal protein, healthy fat, and whole food carbohydrates at each meal and snack.
• Decrease or eliminate your caffeine intake. Despite peaking an hour after that delicious cup of coffee (or your caffeine of choice), half of the amount of caffeine can linger in your body after about 5-6 hours. That means an afternoon beverage will leave half of the mg of caffeine in your body by evening time, potentially making it harder to sleep. Experiment with cutting back amounts or not drinking it all together to see if it makes a difference for you.
• Supplement with some key minerals before trying pharmaceuticals. Our most recommended supplement to start with for sleep is magnesium glycinate, the relaxation mineral. It can be hard to get enough magnesium through food alone because of the depletion of minerals in our soil, so most folks are deficient in magnesium. Taking 200mg-600mg before bed can help your central nervous system settle in for REM sleep, help your muscles relax (think no more restless legs!), and aids in other restorative functions in the body. If you are still having trouble falling or staying asleep, additional 5-HTP, L-Theanine, or melatonin might be the perfect combination for your biochemistry. You can read more about these supplements in this article, Trouble Sleeping? These Tips (+ Supplements) May Help.

Quality Sleep For Hormones And Weight
To recap, when we don’t get enough sleep, our hormones compensate and create the sensation of hunger to help keep us awake. Because we feel like snacking and eating more (especially high sugar and processed foods!), our weight is impacted by extra calories we probably wouldn’t consume if well rested. To keep our hormones and our weight balanced, getting quality sleep is key! Incorporate some sleep hygiene tips to make your mornings and evenings set up for good sleep. Work with a dietitian or nutritionist to tweak your food and supplement plan to help you fall asleep and stay asleep. Have patience! Creating new habits can take time, but a full night’s sleep will totally be worth the effort you put in to create the conditions for it.