Sleep & Weight Loss: Sleeping In On Weekends Can Cause Weight Gain
Many Americans don’t get enough sleep during the work week and so sleeping in on the weekends to make up for lost sleep is a common practice, however as counter intuitive as it might seem, that extra sleep can adversely affect your efforts to lose weight and in fact make you more likely to gain weight. Even if you are dieting and being careful about what you eat! How does sleeping in on weekends make you gain weight and stop your efforts to lose weight? The link between sleep and weight loss/weight gain has been very well studied, and in a nutshell, the findings are that if don’t get enough sleep and your sleeping habits are not consistent, you may not lose weight as much as someone else who is getting regular hours of adequate sleep. (Assuming you are both exercising and dieting equally.) Gaining weight and the struggle to lose weight has become a major concern in today’s world, yet few pay attention to the role fluctuating sleep patterns can play in sabotaging weight loss endeavors, and that being sleep deprived, then trying to make up for lost sleep on weekends or off days can cause weight gain. Sleep is such an essential part of our lives, (we spend one third of our lives asleep), and longer sleep times are theorized to be one of key elements of what made us human in the first place. Yet, nowadays being able to get by on small amounts of sleep is considered an enviable trait. To the extent that being able to “function” while in the clutches of sleep deprivation is believed to be an important requirement for doing well in your studies and being successful in the workplace. Productivity is paramount, sleep often seen as an inconvenience to be put off for as long as possible with copious amounts of coffee and energy drinks. Yet, chronic sleep deprivation and attempts to compensate for it may be one of the many factors responsible for our current obesity crisis. In this article we will take a look at the relationship between sleep and weight loss, and how sleeping in on weekends can make you gain weight. More importantly, we will give you some concrete tips to make sure you don’t fall into the pattern of gaining weight from not sleeping enough during the week and then trying to make up for it on the weekends. Thanks for reading and do be sure to share this article with anyone who you think might stand to benefit from it!
Sleep & Weight Loss: Why We Sleep Less & How It Might Cause Weight Gain
Americans today sleep less than at any other point in recorded history, with over a third of all adults sleeping less than seven hours a day. The average human needs anywhere from 7 to as much as 9 hours of sleep each night and so one in seven not hitting that mark means that we truly have a problem when it comes to getting enough sleep. It wasn’t always this way as just a century ago, the U.S. national sleep average was 9-10 hours a night! A veritable dream number (pun intended) by today’s standards, and this reduction in sleep time applies not only to adults, but to children as well. The problem isn’t just longer work hours and the challenge of keeping pace with a more globalized world that requires ongoing communication and awareness of events in different time zones. It’s a new addition to our lives, but so is television and more recently, an environment where we can be constantly connected to the internet. Screens fill our night life with so much stimulation, (and artificial light), that they can lure many away from their much needed time in bed. After a hard day, watching TV, surfing the net and using your mobile device are typical ways to unwind, but it can come at the cost of making both children and adults stay up longer and sleep less. In essence, many sacrifice sleep in exchange for increased productivity and increased entertainment, but this modern penchant for being awake longer comes at a price.
Over the past 28 years, I have helped hundreds of men and women lose significant amounts of weight. That said, there are times when I am faced with clients who are following their diet yet not losing weight as quickly as he or she should. Aside from clinical issues, or medication listing weight gain as a side effect, there are usually two factors that are responsible. The first is alcohol consumption, (see my article Just One Drink Of Alcohol Can Stop You From Losing Weight), and the second is inadequate sleep with inconsistent sleep patterns. There is also a group who have trouble sticking to their diet because they keep late hours.
Staying up later and longer means you have more time to be hungry, especially if you recently started a lower calorie diet. Thus, making it harder to not overeat (often junk food), at the end of the day. Eating more food late at night also makes it physically harder to fall asleep, reduces the quality of your sleep and how long you can stay asleep.[1] All in all compounding the problem of not sleeping the required number of hours. This all makes sense for the clients who didn’t stick to their diets, as there is also a body of research that shows that eating late at night can make you gain weight if you are consuming most of your calories later in the day. (See my article Eating Late and Weight Gain) But why would my clients with irregular sleep habits but who were spot on with their diets not losing weight as much as they should? To solve this puzzle we have to look at the connection between sleep and weight loss.
Why Do Animals Lose Weight When Sleep Deprived But Humans Gain Weight?
In theory the increased stress created by sleep deprivation should make you lose weight, not gain it. And when researchers first started sleep deprivation studies with laboratory animals, they were able to confirm that sleep deprived animals suffer a DECREASE in overall body weight over time.[2, 3] However, while this pattern of sleep deprivation induced weight loss held true for tests with animals, human epidemiological studies showed the very opposite response. As people tend to gain weight when sleep deprived.[3,4,5,6,7] This was somewhat of an enigma, and at first researchers didn’t understand why there was such a discrepancy. All mammals studied lost weight when sleep deprived but humans gained weight if they didn’t get enough sleep and the reason for this seemingly contrary occurrence lies in the differences between real world and laboratory settings. Human sleep deprivation is almost never uniform, but in the laboratory studies, animals were sleep deprived by a consistent number of hours each day, which isn’t an accurate simulation of how humans experience lack of sleep.
As we mentioned earlier, humans need anywhere between 7-9 hours of sleep a night and if you don’t get exactly as much sleep as your body needs, you begin to accumulate what is known as sleep debt. During the week, few of us hit our sleep requirements. In fact, many Americans average 6.8 hours of sleep per night, which doesn’t sound that far off from the 7 hour recommended minimum, but that sleep debts builds up as the days go by. Soon, mental acuity begins to drop off and you start forgetting what being fully rested feels like, although you would jump at the any opportunity to get some extra sleep. When weekends come, (or if you get to a point where the sleep debt is simply too great to continue functioning), most of us will sleep in to try to make up for the sleep lost. This can help tremendously with helping you feel rested and feeling mentally sharp again, but it wreaks havoc with your system as far as weight loss is concerned.
This phenomenon doesn’t only affect humans, as when researchers began modeling animal sleep deprivation studies after more typical human behaviors, the results were very different. Experiments with rats that endured 5 days of sleep deprivation, followed by 2 days of ad libitum sleep allowances, found that while there was an initial loss of body mass in the first weeks, some quite alarming changes in their physiologies was observed. Changes that have helped us better understand the relationship between sleep and weight loss.
Sleep And Weight Loss: How Sleeping In On Weekends Can Make You Gain Weight
This phenomenon doesn’t only affect humans. When researchers began modeling animal sleep deprivation studies with typical human behaviors, the results were very different from what they were previously. Experiments with rats that endured 5 days of sleep deprivation followed by 2 days of unlimited sleep allowance, found that while there was an initial loss of body mass in the first weeks, researchers observed some startling changes in their bodies. Changes that have helped us better understand the relationship between sleep and weight loss.
The first finding with the sleep deprived rats on a 5 day on, 2 day off sleep deprivation schedule, was that they all had substantial INCREASES IN FOOD INTAKE on days that they were sleep deprived.[3]
The second finding was that there was INCREASED WEIGHT GAIN during the weekends (2 day free periods) when the rats were allowed to sleep as long as they wanted.[3]
The third finding involved the comparison between the human simulated schedule sleep deprived rats and a control group that was consistently sleep deprived by the same number of hours each day. As expected, the rats in the control group all lost weight because of the induced sleep deprivation, even though they were eating the same food and the same amounts as the rats on the 5 days on, 2 days off sleep deprivation schedule who all gained weight![3]
Sleep Deprivation and Hormones- Physiological Changes That Make Us Gain Weight
Since activity levels were the same as well for all of the rats in the study, there had to be some physiological changes that occurred as a result of cyclic sleep deprivation that made rats in that group gain weight. There are many well-controlled studies of both humans and animals highlighting that chronic partial sleep loss, (sleep debt), can increase risk of obesity.[4,7] The research shows that there are major changes in metabolism and endocrine function as a result of what we will call “the weekend sleep in to make up for lost sleep” pattern of sleep deprivation. Changes that occur in both adults and children.[4,7] Sleep restriction changes how our body secretes various hormones and in so doing affects our weight loss efforts and our overall health. Here is how sleep deprivation makes us gain weight:
1. Sleep deprivation decreases glucose tolerance, which can make you gain weight, impede weight loss, and also increase your risk of developing diabetes and cardiovascular disease. [8]
2. Sleep deprivation increases insulin resistance, (which can be a precondition to diabetes), and is recognized as a contributing factor to obesity and weight gain. In a bit of a cruel twist, caffeine, which is commonly used to offset the effects of inadequate sleep, can also play a role in increasing insulin resistance as well, a word to the wise who use caffeinated products to offset the effects of sleep debt.[9, 10,11,12]
3. Sleep deprivation increases later day concentrations of the stress hormone cortisol. Which can suppress your immune system and increase susceptibility to disease.[13,14]
4. Sleep deprivation increases levels of ghrelin. Ghrelin is an important hormone that stimulates appetite and desire to eat, which can create overwhelming food cravings that leads to overeating and consequent weight gain. [15,16]
5. Sleep deprivation decreases levels of leptin, a hormone that acts counter to ghrelin, as leptin does the very opposite, by inhibiting our appetite. [17] Thus making it more likely for you to overeat and subsequently sabotaging your weight loss efforts.
Fighting Back- Increasing Quantity & Quality of Sleep As An Aid to Weight Loss
Taken as a whole, chronic sleep deprivation creates a perfect storm of hormonal reactions that increase your risk of obesity and makes it much harder to lose weight and keep it off. As such, a growing number of clinicians recommend increased sleep time in addition to diet and exercise to help prevent the onset of obesity, and increased risk of earlier mortality it brings. It’s a Sisyphean task to get the required amount of sleep but here are some tips that I have used with my clients to help get them on track.
1. Determine How Many Hours of Sleep You Need.
Estimates are that we need a minimum of seven hours of sleep, as any less is associated with weight gain diabetes, hypertension, heart disease and stroke, depression, and increased risk of death. But some need even more. The litmus test for how much sleep you need is to see how much sleep you need consistently over the course of several days when you are not sleep deprived, where you wake up refreshed and without the aid of any alarms.
2. Take A Mini Vacation To Reset Your Sleep Patterns
If you are having trouble with your sleeping patterns, one of the best ways to reset them is to take a small vacation. It doesn’t have to be longer than 3 days, so a long weekend works, and it need not be somewhere exotic. What’s important is that you choose a place and time where you don’t have to worry about keeping a schedule. Start by following the first step to determine exactly how many hours of sleep you need. Then, while you are away, follow a schedule that you can keep based on your regular real-world schedule. Go to bed and wake up at the hours you would like to keep when you are back from your little vacation and upon your return, you should be truly rested and more likely to be on your new schedule. Our bodies work on a 25-hour cycles that require a reset every day to synchronize with the 24 hour cycle of our planet’s rotation. So 3 days of regular sleep in a relatively low stress environment should be more than enough for you to reset your sleep patterns, and so far it has helped several of my clients get on a better schedule. The regularity will make a noticeable difference in how easily you lose weight, but you will have to be vigilant to not slip back into old habits of sporadic sleep patterns.
3. Restrict Internet and Screen Time An Hour Before Bed
There is some evidence that light from bright screens can throw off your body’s built in clocks, making it harder for your body to know when it should be going to sleep. (See my article Eating Late Can Make You Gain Weight and What’s The Best Time To Workout- AM vs PM for more information on how light affects us.) So skip the screens and read a book (a real one) instead. You won’t be as stimulated, and it will be less likely to keep you awake.
4. Avoid Caffeine!
Even a small caffeine intake affects your sleeping patterns, and can make you get used to accumulating sleep debt. Instead of using coffee and energy drinks to combat bad sleeping patterns, work on improving your quality of sleep! If you like the taste of coffee, try decaffeinated coffee, (black of course, with no milk or sugar), and my clients are often surprised at how deeply they slept after quitting coffee and caffeinated products. (Almost all of them said that they had forgotten what a good night’s sleep felt like.)
5. Avoid Alcohol!
Alcohol has the effect of initially making you drowsy, which is why many think of alcohol as sleeping aid. However, alcohol is not just a sedative, but a stimulant and decreases sleep quality.[] Not at all a good practice for a good night’s sleep.[20,21] (And remember that even one drink of alcohol can also inhibit weight loss.)
6. Avoid Fluids An Hour Or Two Before Bed.
Too many trips to the bathroom at night can cut into the quality of your sleep, so as a rule, curb your fluid intake two or three hours before bed. This small step can make a huge difference in how well you sleep at night.
7. Don’t Sleep In Too Much On Weekends
Sleeping the same hours every day goes a long way in increasing your quality of sleep and maximizing your weight loss program. If you absolutely must sleep in on weekends, it might be best to not sleep any more than an hour extra. The studies have yet to define a minimum dose limit for how many extra hours lead to weight gain if you are sleep deprived, and so it might be best to add as little extra sleep in time on weekends as possible, as it might make you gain weight. Better yet, try to get 7 hours of sleep during the week, so you won’t feel like you have to sleep in on weekends. It will go a long way in improving your health as well!
5th Avenue Gym circa 2009- 5 years out from my last show.
As you can see, trophies and competitions were NEVER the driving force behind why I train the way I train and why I eat the way I eat.
It's always been my passion to see how far I could go as a natural athlete and perhaps even more so, to show what can be accomplished without using drugs.
And 5th Avenue Gym was the perfect place to do it.
I really miss that gym.
It was a place where legends came to train and while it wasn't pretty, it had everything we needed to do the work we needed to do.
And boy did we work!!!
5th Avenue for life as they say!!!
Hope you are still training hard and as always, Excelsior!!! #naturallyintense
And thanks @pit_bulls_67 for snapping the shot!!!!
#naturalbodybuilder #naturalbodybuilding #throwback #fifthavenuegym #5thavenuegym #drugfreebodybuilding #naturalbodybuildinglifestyle #gym #gymlife #gymmotivation #naturalbodybuildingmotivation #bodybuilding #bodybuildinggym
Why Are Pull Ups So Hard For Some But Not For Others?
Pull ups are an exercise people love to hate!
They love to hate it because in my experience, most untrained men or women can't do one pull up and those who train can often struggle to do 6 or 10.
Why?
Because pull ups are hard!
And yet people like myself can easily do as many as 20-25!
So what's the reason for this discrepancy?
Is there some secret that allows me and others to do pullups so easily?
There isn't, and in this video I go over exactly why I can do as many as I can and why it can be so much harder for others.
I also go over my #1 pull up variant that ANYONE can do, even if you can't do one pull up.
And yet it can build strength and muscle size in some cases even more so than regular pull ups!
So click the link in my bio to see the full video on YouTube or go to my channel by looking up naturallyintense!
Thanks in advance for watching and as always, Excelsior!!! #naturallyintense
#pullups #highintensitytraining #naturalbodybuilder #naturalbodybuilding #fitover40 #naturalbodybuildingvideos #backworkout #pullupworkout #naturalbodybuildingtips #backtraining #highintensitytrainingtips #hometraining #trainingtips #bodybuildingtips
Maximize Biceps Growth With High Intensity Arm Blaster Hammer Curls!
50lb Dumbbells For 20 reps!
The Arm Blaster is a fantastic piece of equipment for a home gym or any gym!
It doesn't take up much space and allows you to add variety to your biceps training.
It locks your elbows in place, thus increasing training intensity, and by doing a hammer curl, you can use more weight (thus increasing intensity even more) and target your brachialis muscles which help add density to your biceps!
This was my last set and I couldn't go any heavier as I am still nursing a wrist injury, but the 50lbers were more than enough to do the job!
Try them out next time you train arms and let me know how it goes!!!
Still training, hope you are too and as always, Excelsior!!! #naturallyintense
#hometraining #homeworkout #homeworkout #nuobell #highintensitytraining #naturalbodybuilder #naturalbodybuilding #fitover40 #naturalbodybuildingvideos #armworkout #bicepsworkout #naturalbodybuildingtips #biceps #armtraining #bicepsworkout #highintensitytrainingtips #drugfreebodybuilding#powertec #armblaster #hammercurls
Injury-Proof Your Training: The Power of Workout Variation!
One of the main reasons why I can still train heavy and intensely at 49 after 35 years of nonstop training without any training related overuse injuries is the fact that I vary EVERY workout!
Overuse injuries come from doing the same movements over and over and by always changing your routine, you radically lessen the likelihood of chronic injury.
Squats, deadlifts, barbell curls and bench presses are great exercises, but if you do them all the time, you do increase the odds of getting injured.
And as a natural athlete, it bears mentioning that it takes years to realize your full potential, and so it's crucial to have a training program that is sustainable, and one that will allow you to train injury free for as long as I have or longer!
Thanks so much for tuning in and as always, Excelsior!!! #naturallyintense
#naturalbodybuilding #naturalbodybuildingtips #naturalbodybuilder #naturalbodybuildingvideos #injuryprevention #fitover40 #workout #gymlife #workouttips #trainingmotivation #naturalbodybuildingmotivation #drugfreebodybuilding #highintensitytraining #injuryfreetraining #longevity
High Intensity Training Leg Extensions To Failure!
And as always, Excelsior!!! #naturallyintense
#naturalbodybuilding #naturalbodybuilder #highintensitytraining #highintensitytrainingtips #hometraining #homeworkout #fitover40 #naturalbodybuildingvideos #naturalbodybuildingtraining #naturalbodybuildingtips #naturalbodybuildingmotivation #legextensions #legday #legworkout #powertec #legdayworkout
This Is What 35 Years of Natural Bodybuilding Looks Like!
So as you know, As you may know I recently turned 49 and every year I do a photoshoot to show my progression.
In the hopes of showing that you can not only maintain a level of excellence as the years go by, but that you can do it without steroids, TRT, drugs or even pre-workouts and protein shakes!
(I’ve never had a pre-workout or energy drink and haven’t had a protein shake in decades!)
You don't need it as all it does make you forget tht excellence doesn’t require anything outside of yourself.
You already have all the tools you need!
Not a huge fan of taking photos of myself, (I much prefer being behind the camera) but I humbly try to be one example of just how much you can achieve with proper training and an uncompromisingly proper diet!
So here I am again at 49 and I am looking forward to seeing what you accomplish over the years as well!!! Thanks so much for tuning in and as always, Excelsior!!! #naturallyintense
#naturalbodybuilding #naturalbodybuilder #naturalbodybuildingvideo #naturalbodybuildingmotivation #naturalbodybuildingtips #highintensitytraining #drugfreebodybuilding #nodrugs #fitover40 #fitoverforty
High Intensity Arm Training- 50lb Concentration Curls!
There are two basic types of exercises, compound movements like barbell curls and isolation movements like concentration curls.
If you want above average arm development, you have to go hard on all exercises.
Isolation movements included, especially if you are drug free as we don't have the privilege of maximum growth from anything less than putting in some seriously hard work!
You have to go to that dark place where you can barely get the weight to move and do whatever it takes to get it up!
And then somehow find it in you to do it again!!!
You can't intellectualize it, you just have to do it and believe!!!
This was my third and last set and so I went all out!
My wrist is still a bit off so not going ultra heavy (by my standards) but
this was a hard set!
I haven't done concentration curls in a while, so I am really sore right now as I type this out two days after the workout!
Bear in mind that I always try to change it up and no one exercise is done every time I train.
Never training to maintain, always working hard to gain!!!
Still training and I hope you are too!!!
Thanks for tuning in and as always, Excelsior!!! #naturallyintense
#hometraining #homeworkout #homeworkout #roguerack #nuobell #highintensitytraining #naturalbodybuilder #naturalbodybuilding #fitover40 #naturalbodybuildingvideos #armworkout #bicepsworkout #naturalbodybuildingtips #biceps #armtraining #bicepsworkout #highintensitytrainingtips #drugfreebodybuilding
Unlock Your Natural Potential By Varying Your Workouts!
For the past 32 years I have always done a different workout every time I trained.
I have never followed a set program of exercises and the only unifying aspect of my workouts is the blistering intensity!
I train three times a week with a protocol I call Naturally Intense High Intensity Training, and what distinguishes it from other forms of high intensity training is the constant variety.
Muscles grow in response to overload and UNACCUSTOMED stimulation.
Remember when you first started training how effective everything seemed to be, but over time that progress slowly ground to a halt.
You change your routine and see some progress, but the gains in size and strength inevitably fall off over time if you don't make a change.
Now what if you never left that "beginner gains" stage and were always training with different exercises and radically different ways of doing the exercises every single time?
You would be where I am, not having experienced a plateau over the past 32 years and be able to really start unlocking your natural potential!
How does it all work, and how would you measure progression? Watch the full video on YouTube by clicking on my bio link, or going to my YouTube channel (Naturally Intense) and see for yourself!
I really think it can help make a difference in your overall progress, and best of all, it helps you avoid injuries so you can keep training hard for years on end! Thanks in advance for watching and as always, Excelsior!!! #naturallyintense
#naturalbodybuilding #naturalbodybuildingtips #naturalbodybuilder #naturalbodybuildingvideos #workout #workouttips #fitover40 #gymlife #workoutmotivation #trainingmotivation #naturalbodybuildingmotivation #drugfreebodybuilding #highintensitytraining #highintensitytrainingtips #HIT
Please note that all material is copyrighted and DMCA Protected and can be reprinted only with the expressed authorization of the author.
CLICK FOR A FREE COPY OF KEVIN’S WEIGHT LOSS EBOOK!
Featured everywhere from the Wall Street Journal to CBS News, Kevin Richardson’s Naturally Intense High Intensity Training have helped hundreds lose weight and transform their bodies with his 10 Minute Workouts. One of the top natural bodybuilders of his time, Kevin is also the international fitness consultant for UNICEF and one of the top personal trainers in New York City. Click to learn more about:
Online personal training with celebrity personal trainer Kevin Richardson!
References For Sleep & Weight Loss: How Sleeping In On Weekends Can Make You Gain Weight
1. Stunkard A, Allison K., Lundgren J. Issues for DSM-V: Night Eating Syndrome- Am J Psychiatry 2008
2. Everson CA. Functional consequences of sustained sleep deprivation in the rat. Behavioral Brain Research 1995
3. Barf RP, Desprez T, Meerlo P, Scheurink AJ. Increased food intake and changes in metabolic hormones in response to chronic sleep restriction alternated with short periods of sleep allowance. Am J Physiol Regul Integr Comp Physiol. 2011
4. Taheri S, Lin L, Austin D, Young T, Mignot E. Short Sleep Duration Is Associated with Reduced Leptin, Elevated Ghrelin, and Increased Body Mass Index. PloS 2004
5. Lyytikäinen P, Rahkonen O, Lahelma E, Lallukka T. Association of sleep duration with weight and weight gain: a prospective follow-up study. J Sleep Res. 2011
6. Nielsen LS, Danielsen KV, Sørensen TI. Short sleep duration as a possible cause of obesity: critical analysis of the epidemiological evidence. Obes Rev. 2011
7 Leproult R, Van Cauter E.Role of sleep and sleep loss in hormonal release and metabolism. Endocr Dev. 2010
8. Barr EL, Zimmet PZ, Welborn TA, et al. “Risk of cardiovascular and all-cause mortality in individuals with diabetes mellitus, impaired fasting glucose, and impaired glucose tolerance: the Australian Diabetes, Obesity, and Lifestyle Study 2007
9. Graham, TE; Sathasivam, P; Rowland, M; Marko, N; Greer, F; Battram, D. Caffeine ingestion elevates plasma insulin response in humans during an oral glucose tolerance test. Canadian Journal of Physiology and Pharmacology 2001
10. Keijzers, GB; De Galan, BE; Tack, CJ; Smits, P. Caffeine can decrease insulin sensitivity in humans. Diabetes Care 2002
11. Petrie, HJ; Chown, SE; Belfie, LM; Duncan, AM; McLaren, DH; Conquer, JA; Graham, TE. Caffeine ingestion increases the insulin response to an oral-glucose-tolerance test in obese men before and after weight loss. The American Journal of Clinical Nutrition 2004
12. Akiba, T; Yaguchi, K; Tsutsumi, K; Nishioka, T; Koyama, I; Nomura, M; Yokogawa, K; Moritani, S et al. Inhibitory mechanism of caffeine on insulin-stimulated glucose uptake in adipose cells. Biochemical Pharmacology 2004
13. Palacios R., Sugawara I. Hydrocortisone abrogates proliferation of T cells in autologous mixed lymphocyte reaction by rendering the interleukin-2 Producer T cells unresponsive to interleukin-1 and unable to synthesize the T-cell growth factor. Scand J Immunol 1982
14. Besedovsky, H.O.; Del Rey, A.; Sorkin, E. Integration of Activated Immune Cell Products in Immune Endocrine Feedback Circuits. in Leukocytes and Host Defense 1984
15. Inui A, Asakawa A, Bowers CY, et al. “Ghrelin, appetite, and gastric motility: the emerging role of the stomach as an endocrine organ. FASEB J. PMID 2004
16. Castañeda TR, Tong J, Datta R, Culler M, Tschöp MH. Ghrelin in the regulation of body weight and metabolism. Front Neuroendocrinol. 2010
17. Brennan AM, Mantzoros CS. Drug Insight: the role of leptin in human physiology and pathophysiology–emerging clinical applications. Nat Clin Pract Endocrinol Metab 2006
18. Center For Disease Control and Prevention: Behavioral Risk Factor Surveillance System (BRFSS) 2014
19. Watson NF, Badr MS, Belenky G, et al. Recommended Amount of Sleep for a Healthy Adult: A Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society. Sleep. 2015
20. Palmer, C.D., Harrison, G.A.; Hirons, R.W. Association between smoking and drinking and sleep duration. Annals of Human Biology 1980.
21. Roehrs, T.; Yoon, J., Roth T. Nocturnal and next-day effects of ethanol and basal level of sleepiness. Human Psychopharmacology 1991.
