Does Sleep Deprivation Really Impact Weight Loss?

Jessica Smith
by Jessica Smith
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Does Sleep Deprivation Really Impact Weight Loss?

The saying goes that “if you snooze, you lose,” but when it comes to weight loss, this adage may actually work in your favor. Most people are shocked when I tell them the most important factor for losing weight (and keeping it off) isn’t diet or exercise, it’s sleep!

Here’s why: If you aren’t getting enough shut-eye every night, research has shown that not only are you making it harder to stick with a healthy diet, but you’re also going to lack the energy and stamina you need to stay active and give your all to your workout program. And, while additional research is needed, more and more evidence is showing us the importance of sleep for slimming down. I’m convinced that a lack of sleep is the reason that most adults find the scale is stuck, despite their best efforts to lose weight.

Not convinced? Check out what happens when you don’t get enough sleep. (For most adults, “enough” is somewhere between 7–8 hours a night.)

1. Your metabolism slows down.

You may have read that a lack of sleep can slow your metabolism, but did you know that it can happen after just one night of sleep deprivation? One Swedish study found when a group of healthy, young male subjects stayed awake all night, their metabolic rate slowed, reducing their energy expenditure for tasks such as breathing and digestion by as much as 20% the next day. Additional research suggests that not sleeping enough on a regular basis can cause profound, negative effects on metabolism.

2. Your appetite for high-calorie, high-fat foods increases.

Feeling tired may make it harder to say no to those doughnuts at the office. According to one 2012 study, when subjects slept just an hour and 20 minutes less each night, they consumed an average of 549 additional calories the next day — and they weren’t snacking on salad!
Sleep has a direct influence on your body’s levels of the appetite stimulating and controlling hormones ghrelin and leptin, making it harder for your body to recognize when you’ve eaten enough. Although it’s not clear exactly why, lack of sleep may also cause cravings for higher-fat, higher-calorie foods.

3. Your energy and energy output (aka calorie burn) decreases.

You might think that since you’ll be awake longer, you’ll have more opportunities to burn off extra calories, right? Not exactly. Some research has shown that sleep-deprived people are less likely to be physically active than those who are well-rested. Think about it: When you’re tired, you aren’t exactly bursting with energy, right? You’ll probably find yourself less active overall during the day, and getting through a tough workout? Forget about it. Sleep can actually enhance your performance at the gym, so don’t discount it if one of your goals is to improve your fitness level and change your body composition.

4. You’re more likely to get the late-night munchies.

Staying awake for more hours equals more time and opportunities to eat additional calories. While it’s not a guarantee that you’ll eat more if you stay awake longer, extra hours of access to the fridge may increase your chances of snacking more. There’s a reason they call them midnight munchies. Plus, most of us tend to eat more mindlessly at night in front of the TV, so watching those late, late shows may also be causing you to overdraw from your calorie bank.

5. You increase your risk of diabetes and heart disease.

Not getting the right amount of sleep can also weaken your immune system and put you at a greater risk for disease. One Massachusetts Male Aging Study found that subjects who slept less than six hours a night were twice as likely to develop diabetes over the 15-year study period. Sleep deprivation may also put you at a higher risk for heart disease. One study found that subjects who got less than five hours of sleep a night showed increased risk factors for cardiovascular disease,such as increased heart rate and higher levels of C-reactive protein, which rises in response to inflammation. And yet another long-term Nurses’ Health Study found that women who slept less than five hours a night were 15% more likely to become obese during the research period of 16 years.

The takeaway here? Don’t sabotage all of your hard work by skimping on sleep. Make it a priority to get enough rest to stay healthy and shed pounds. While it may feel impossible at first, it’s much more manageable if you start small. Rather than suddenly hitting the hay a few hours earlier from one night to the next, try heading to bed 15 minutes earlier every night for a week until you’ve gradually shifted your bedtime back to meet your personal sleep needs. In an ideal world, you would wake up before the alarm — or at least rise feeling refreshed.

You may find that sleep is the missing element in your healthy lifestyle — and that it can bring back your energy and vibrancy and help you reach your weight loss and fitness goals faster.

Tell us: What do you think? Have you noticed a difference in your energy, appetite, etc. when you don’t get enough sleep? Are you getting enough sleep each night? Let’s keep this discussion going; share with us your best tips and observations in the comments below!


> 15 Inspirational Tips from MyFitnessPal Users Who’ve Successfully Lost Weight
> Does Sleep Deprivation Really Impact Weight Loss?
> The Sleep-Weight Connection

About the Author

Jessica Smith
Jessica Smith

As someone who struggled to lose weight for years, Jessica found that the key to her own 40-pound weight loss was making small, healthy lifestyle changes that led to big, lasting results. Now, as a certified wellcoach, fitness instructor and personal trainer, she has spent the last 15 years helping students and clients reach their goals in New York City, Los Angeles and Miami. She now reaches millions online through her YouTube Channel and home exercise DVD series. Please visit to learn more about her fun, results-driven programs for all levels of exercisers.


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