Sleep and Weight Loss: How They’re Connected

Did you know that sleep and weight loss are intimately connected? Yes, sleep is required for your metabolism to function the way it should. And lack of sleep or poor sleep, even for a short period of time, can send your metabolic hormones into a tailspin. 

Unfortunately, that means if you’re trying to lose weight without regularly getting quality sleep, you may feel like you’re fighting a losing battle.

Let’s look at how sleep affects your cortisol, insulin, leptin, and ghrelin — and what that means for your metabolism. Plus, I’ll show you how to get into a solid sleep routine and harness the metabolic benefits of a great night’s sleep. 

How Does Sleep Affect Weight Loss?

Sleep affects weight loss in a few different ways. For starters, your body needs sleep to repair and recharge. When you don’t get enough sleep, it’s harder to have the energy for things like exercise and movement. That can certainly impact weight loss.

And then there’s the fact that sleep is linked to weight loss directly through some of your metabolic hormones. 

First up on the list of these hormones is cortisol. You may be surprised how cortisol, sleep, and weight loss are all interrelated.

Cortisol And Weight Gain

When you don’t sleep enough, it can cause your body to produce the stress hormone cortisol. (1,2,3) And here’s the thing about excess cortisol — it isn’t good for your metabolism. In fact, cortisol has been linked to belly fat, overeating, and weight gain. (4,5)

Cortisol And Sleep

While cortisol is famous for being the “stress hormone” it also plays a huge role in your sleep-wake cycle. When things are working the way they should, cortisol and sleep should have an inverse relationship. Ideally, at night, your cortisol levels should be low and your melatonin levels should be higher. Then, in the morning, your body prepares to wake up with a gradual increase in cortisol. 

Cortisol isn’t necessarily “bad.” After all, it’s a powerful anti-inflammatory and it helps regulate several bodily functions. But it isn’t an ideal constant daily companion, either. Prolonged cortisol secretion can wreak havoc on your body and brain. (6)

The problem with cortisol and weight gain arises when you’ve already got stress going on during the day (who doesn’t?), and then you’re not sleeping well at night. This makes your body feel like it’s stressed out all the time. You’re being flooded with cortisol night and day. You can imagine that this would make falling asleep and staying asleep difficult. 

And then, the difficulty sleeping only increases your cortisol response. So it’s like a never-ending cycle of poor sleep and too much circulating cortisol.

This is how cortisol causes weight gain.

Leptin, Ghrelin, And Sleep

It’s also worth mentioning the relationship between sleep and leptin and ghrelin as well. 

Leptin is a hormone that tells your brain you’re full. (7) Researchers speculate that cortisol levels could influence leptin levels — and that women who have difficulty with cortisol regulation could be at greater risk for obesity and weight gain as a result. (8)

Ghrelin is a hormone that tells your brain that you’re hungry. (9) It is believed that both ghrelin and leptin may play a role in weight gain and obesity. (10) 

Here’s the interesting thing — sleep deprivation can alter leptin and ghrelin levels. In a study of over 1,000 volunteers, those with short sleep had reduced leptin and elevated ghrelin. Meaning sleep deprivation induced the production of hormones that made them feel hungrier! (11)

Another study looked at participants who slept less than 6.5 hours each night. When researchers encouraged healthy sleep hygiene habits and the participants increased their slumber by an hour a night for two weeks — the control group consumed about 270 calories less per day and lost around a pound. While the study didn’t measure leptin or ghrelin, it indicates the powerful relationship between a good night’s sleep and hunger levels. (12)

Does Sleep Affect Blood Sugar?

Just like with cortisol, leptin, and ghrelin, insulin is another hormone that is affected by lack of sleep. (12)

Insulin is a very important hormone that helps fuel your body. When you eat food, your body turns that food into glucose (a sugar) which is what your cells use for energy. Insulin is like the key your cells need to unlock the door to let glucose in. 

As you age, you become more “insulin resistant.” This is a state where your body finds it harder to respond to insulin and as a result, glucose can’t get into the cells…so it turns around and goes back into the bloodstream. This results in elevated blood sugar levels. (13)

It also typically means weight gain. 

What’s more, weight loss usually improves insulin sensitivity. So this becomes another vicious cycle. Weight gain leads to insulin resistance, which in turn leads to weight gain.

And, your sleep and blood sugar are similarly tied together. In fact, research indicates just one single night of poor sleep can mean bad news for your blood sugar. (14)

Menopause And Perimenopause Insomnia

Here’s the really unfair part: sleep problems, menopause, and perimenopause go hand in hand. This could be one of the reasons so many women start to see sudden weight gain in perimenopause.

With your hormones affecting your sleep and your sleep affecting your hormones, it can feel like an impossible battle to win. With perimenopause night sweats and waking up in a panic thanks to 3 am cortisol spikes, how are you supposed to make peace with your hormones and sleep? How are you supposed to stave off weight gain that starts in perimenopause?

How To Improve Your Sleep For Weight Loss

If you’re in menopause or perimenopause and gaining weight, it’s a smart idea to start by looking at the relationship between your sleep and weight loss

After all, as we’ve seen, getting more sleep can create an amazing foundation for your metabolic health — and it can certainly be a part of your menopause and perimenopause weight gain solution.  

Getting a better night’s sleep and achieving weight loss during perimenopause and menopause isn’t impossible.  

Here are 4 simple things you can do to get your sleep schedule under control and start enjoying all the weight loss benefits of a regular, solid, night’s sleep.

1. Determine How Much Sleep Is Enough

Most experts recommend that you get between 7 and 9 hours of sleep every night. (16) The exact amount that feels right for you can vary. And, it’s important to note that just because you’re “asleep” doesn’t mean you’re necessarily getting quality, restorative sleep. If you’re in bed for 9 hours, you may only be getting 7 hours of sleep. A digital sleep monitor can help you determine more if you’re sleeping through the night, but not waking up feeling totally rested.

2. Create A Bedtime Routine

Yes, bedtime routines are for adults, too. Your body actually responds really well to a soothing nighttime routine that lets it know it’s time for bed. You can make this routine anything that feels good to you, but it is important to limit caffeine, screens, heavy snacks, liquids, and alcohol before bed. A nighttime meditation and diffusing soothing essential oils in your bedroom can go a long way toward calming your nervous system and preparing for a restful night’s sleep.  

3. Magnesium And Sleep

Magnesium is one of those minerals that most people don’t get enough of, and it’s important for so many bodily functions. Studies indicate magnesium supplements could improve sleep quality. (17) Magnesium is found in foods like spinach, nuts, and avocado, so be sure to add these to your daily Keto-Green® diet rotation. Magnesium is also one of the key ingredients in my Night-Zzz formula.  

4. Exercise And Sleep

Exercise and sleep have one of those cyclical relationships we’ve seen a few times throughout this article. On the one hand, you typically need to be well-rested to feel like exercising. And then, on the other hand, exercise can help you sleep better at night. In fact, one study showed just 4 months of exercise improved sleep quality in study participants suffering from insomnia. (18) As a general rule, try to get your exercise in earlier in the day — exercising too close to bedtime can have the opposite of the desired effect on your sleep.

Sleep And Weight Loss: Mastering Quality Sleep

Sometimes, even when you create a lovely nighttime routine, and get your exercise in earlier in the day, you still want a little extra help to flip that sleep switch on at night. 

And that’s where my Night-Zzz caps come in.

Night-Zzz is a combination of several super-ingredients that work together to make falling and staying asleep positively blissful. 

Plus, it’s loaded with natural compounds that encourage overall hormone balance and supercharge your metabolism too. We’re talking maca for cortisol support and cinnamon for extra blood sugar love.    

Click here to learn more about Night-Zzz and how it can help you get the rest you deserve!


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Dr. Anna Cabeca

Dr. Anna Cabeca

Certified OB/GYN, Anti-Aging and Integrative Medicine expert and founder of The Girlfriend Doctor. During Dr. Anna’s health journey, she turned to research to create products to help thousands of women through menopause, hormones, and sexual health. She is the author of best-selling The Hormone Fix, and Keto-Green 16 and MenuPause.

Learn more about my scientific advisory board.