Sleep: The Forgotten Fat Loss Habit

By Devin Gray, CSCS

Are you doing everything right in the gym and in the kitchen, but still struggling with your results?

In this article, I’ll show you how a lack of sleep can sabotage your fat loss efforts and wreak havoc on your hormones.  I’ll also share with you my best tips and resources for more, better quality sleep.

I’m not exaggerating here – getting enough sleep is the most important habit. I really, truly mean this. Why? Because it has arguably the largest impact on your health.

The long-term effects of sleep deprivation (<7 hours per night) have been linked to a 15% greater chance of early death, according to the National Institute of Health (NIH). More on that here.

What’s more, not sleeping enough will make you fat.

Studies have repeatedly demonstrated that sleeping less than 7 hours per night will cause you to gain more weight over time, even if you’re exercising and dieting. Once again: even on a great diet and a killer exercise plan, you are less likely to lose fat (and more likely to gain weight) if you are sleep deprived.

Even worse, you’re more likely to lose valuable lean muscle mass instead of fat if and when you do lose weight!

The National Sleep Foundation recommends an average of 7-9 hours for most adults. Research shows that 7-8 hours is ideal, especially if you;re exercising.

The National Sleep Foundation recommends 7-9 hours of sleep per night for most adults. Much of the research on health risks have shown similarities in the risks from oversleep (>9 hours) as under sleep (>7 hours). We recommend 7-8 hours per night.


Today, Americans Sleep Less Than Ever and Weigh More Than Ever

Put simply: Two-thirds of adults in the USA are overweight and one-third of adults in the USA sleep less than 6 hours each night. This makes it easy to assume that many adult Americans are sabotaging their efforts in the gym and in the kitchen by not getting enough sleep. This correlation, while not causative, has been shown to be significant enough to be noted as a public health risk by the National Institute of Health. (No, really. Check out their fact sheet.)

Here’s the breakdown and recent stats on sleep deprivation and obesity in the USA:

  1. Good sleep is defined as between 7-9 hours per nightand a bedtime before midnight.
  2. Several studies show that people who sleep less than 7 hours per night gain more weight over a period of 5 years, even when dieting and even when research is designed to control for differences in lifestyle, health, and demographic.
  3. Adult Americans are sleeping less than ever. ~20% of adults are sleep deprived.
  4. As recently as 2004, over 30% of men & women ages 30-64 reported sleeping less than 6 hours each night. In 1985, that was closer to 25%.
  5. In that same time period, obesity has also increased nationwide. In 1985, most states didn’t even report obesity rates and the worst on record reported that only 10-14% of adults were obese.
  6. Currently, the U.S. Centers for Disease Control & Prevention (CDC) report that 34.9% of US adults are medically obese and a whopping 68% of adults are overweight.
Tip: Reserve your bed for sleeping only.

Tip: Don’t ruin a comfy bed by doing too many things in it!
Train your brain that your bed is for sleeping in. It might help you to fall asleep faster.

Fast Facts About the Relationship Between A Lack of Sleep and Weight Gain


Sleeping less than 7 hours per night can make you gain more weight than you normally would.

  • There is a strong association between sleeping less overall and gaining more weight, even over a period of 5 years. This persists even if demographic, lifestyle, health, and work are considered.
  • According to the NIH, adults who sleep less than <6 hours were 5x more likelyto have a high BMI by age 27!

Sleep deprivation can wreck your diet.

Good sleep is associated with being less likely to develop Type II Diabetes.

  • People that sleep 7-8 hours a night are less likely to develop Type II Diabetes, while people that sleep 5-6 or 8-9 hours are more at risk. According to the NIH, adults that sleep 6 hours are 1.7x more likely to have diabetes. This is independent of obesity and waist size!

You can handle carbs better if you get good sleep, meaning that you’re less likely to store them as fat.

  • One of the key strategies for fat loss is to increase your body’s sensitivity to insulin. In contrast, many metabolic diseases and Type II Diabetes are marked by a pronounced resistance to insulin.
  • One week of consistently reducing sleep by 2 hours can cause insulin resistance and just a single night of 4 hours of sleep will cause it – even in healthy people! More on that here:

Sleep deprivation messes with your metabolism and how your body produces metabolic hormones such as thyroid, growth hormone, and testosterone.

  • In men, testosterone can lower by 10-30% following long-term reductions in sleep. (So, if you’re spending a bunch of money on T-boosting supplements, you better be sleeping!)
  • Irregular sleep can affect when your body creates growth hormone, a major metabolism-boosting hormone – especially in young people.
  • Sleep deprivation wreaks havoc on the production of thyroid stimulating hormone and therefore the regulation of your thyroid gland.

Sleep deprivation alters your mood and can make you depressed, anxious, and more likely to abuse alcohol.

  • In both adults and teenagers, sleep deprivation or sleep loss increased the likelihood and severity of mental distress. It’s also suggested that sleep deprivation’s effect on mood is more severe than the effects on cognitive functions. (And we all know how hard it is to think when you’ve had a bad night’s sleep)

To be clear: not getting enough sleep can sabotage all the hard work you’re doing with your diet and exercise.

Sleep is the bedrock of your results and it’s key to your success. There are countless bodybuilders and movie stars with impeccable diets, ridiculously hard workouts, and great results that swear up and down by the importance of sleep.

And, it doesn’t take any hard work! You just need to take steps towards getting to bed earlier and getting more restful sleep.

With that in mind, here are 9 steps you can take to get better sleep:


Nine Recommendations For Sleeping More and Sleeping Better

  1. Sleep for 7-8 hours every night. This sleep window is associated with all of the best results for improved insulin sensitivity, mood, brain function, and hormone regulation. The worst consequences come from sleeping 4 hours per night
  2. Decide on a consistent bedtime and wakeup time – even during the weekends.
  3. Create your own “sleepcave”– very dark, very quiet (white noise can help), and ideally used only for sleeping. Not for reading, watching TV, or playing on your tablet. Think of it as training your body to associate your bed with sleeping. This can help you to fall asleep faster.
  4. Commit to a bedtime routine. Read, meditate, foam roll & stretch, take a bath, journal – whatever floats your boat. However..
  5. Power down your electronics for at least 30 minutes before bedtime.
  6. Avoid stimulating activities shortly before bed. This includes reading exciting books! If it’s a real page-turner, save it for later. (I’m guilty of this one!)
  7. Limit coffee to the morning, not in the afternoon or evening. Or simply go decaf.
  8. Exercise on a regular basis to burn off excess energy. I know that I personally have a much harder time sleeping if I miss consecutive workouts.
  9. If falling asleep or staying asleep is difficult, consider sleep supplements such as melatonin. chamomile, and valerian. It may also be time to talk to your doctor and consider requesting a sleep study.


Remember: start with just 1-2 habits at a time. You’re more likely to succeed (85%!) and see better progress. It might take you a full 6-8 weeks to really overhaul your sleep patterns. That may sound like a long time, but it’s far shorter than attempting 6 new habits, losing track of them, and quitting.

If you need more guidance, I recommend reading a few of the following guides. They’re much more in-depth and really dig in.

Recommended Reading:

  1. Precision Nutrition’s “All About Sleep” – learn more about how sleep affects your body
  2. Precision Nutrition’s “Hacking Sleep” – learn much, much more about creating an optimal sleep environment
  3. NIH’s Sleep Disorders & Sleep Deprivation: An Unmet Public Health Problem– Chapter 3. If you’re into the nitty gritty, or question some of the health claims made here, read this chapter. It’s an excellent summary of the current research. By excellent, I really mean terrifying.
  4. The National Sleep Foundation
  5. Examine’s Research Summaryof Effects of Sleep on Health
Do you have questions or comments on this article?

E-mail me at

I can help you whittle down a habit into easier steps if you need me to. Or just introduce yourself and let me know what your ultimate goal is.

If you know that you need help, let’s book a free 15 minute coaching call.

You’ll work with me 1 on 1 to come up with an action plan so that you start making progress – right away.

Meet the Author: Devin Gray

Meet the Author: Devin Gray

Founder, Head Coach

NSCA-CSCS, FMSC, Pn1 Certified
B.S. in Exercise Science - Texas A&M University

Devin is the owner & head coach of Optimize Fitness & Performance. He helps people become stronger and perform their best. Devin is especially focused on helping people with injuries learn to workout safely after they finish physical therapy.

You can book a free 15 minute coaching call with Devin by clicking here.

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