When It Comes to Sleep, Average is Best

Sleeping too little – or too much – can increase your risk for future weight gain, according to a study published in the April 1 issue of the journal Sleep.

For the study, researchers from the Laval University in Quebec, Canada evaluated the sleep habits and body composition of 276 adults between the ages of 21 and 64.

After adjusting for age, gender and baseline body mass index (BMI) the researchers determined that across the six year study period, those who slept for five to six hours per night gained 1.98 kg (4.36 lbs) more than “average duration” sleepers who slept between seven and eight hours per night. Those who slept between nine and 10 hours per night, meanwhile, gained 1.58 kg (3.48 lbs) more than average duration sleepers. In addition, the researchers report that the risk of becoming obese was elevated for both short and long duration sleepers, with short duration sleepers experiencing a 27% increased obesity risk and long duration sleepers experiencing a 21% increased risk compared to average duration sleepers.

Commenting on the findings, the study’s lead author notes that it “provides evidence that both short and long sleeping times predict an increased risk of future body weight and fat gain in adults,” adding that the data “emphasize the need to add sleep duration to the list of environmental factors that are prevalent in our society and that contribute to weight gain and obesity.” Ultimately, he recommends that sleep habits be included alongside healthy eating and physical activity in discussions about how to manage the current obesity epidemic.

It seems that when we’re talking about sleep, we’re almost always focusing on the fact that we just can’t get enough! However, this study shows that too much of a “good” thing might not be all that good for you, with people who are snoozing away the better part of the day (college co-eds come to mind here!) perhaps actually doing themselves a disservice.

All in, it would seem that this study proves that sleeping is (yet another) item that should be added to the “everything in moderation” list of life!

bitzcelt, Nick Wilkes Flickr Photos (CC)

Further Reading:

Frequent Sleep Disruption Increases Risk of Kidney, Heart Disease

7 Tips to Get Out of Bed

How to Avoid Jet Lag

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24 thoughts on “When It Comes to Sleep, Average is Best”

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  1. Wonder how quality of sleep figures (apparently not measured in the study). I know when my sleep quality is poor, I crave more sleep time (and it doesn’t make up for the lack of good sleep).

  2. Since I had a period of increasingly worse sleep a few years back I have been thinking about this a bit.

    “provides evidence that both short and long sleeping times predict an increased risk of future body weight and fat gain in adults,” adding that the data “emphasize the need to add sleep duration to the list of environmental factors that are prevalent in our society and that contribute to weight gain and obesity.”

    I’m not so sure *contribute* is the right word here. Correlation and association, perhaps. For instance, thyroid disorders (which is very common) as well as perimenopausal and menopausal hormonal shifts can negatively impact sleep quality and duration, and both are associated with weight changes, for instance. Sleep apnea is also a hypothyroidism symptom, and sleep apnea can affect sleep quality and duration.

    So I would guess there are other things (perhaps multiple) going on *causing the weight gain*, not simply the amount of sleep.

  3. This is so stupid.

    If you sleep less you’re awake more and thus you have more time in which to feel hungry and eat.

    If you sleep more, you’re very likely lazy, slothful, etc., and so you probably also over-indulge in other areas, like food.


  4. It think it’s more likely that there is some underlying health issue that leads to both oversleeping and weight gain.

  5. That man sleeping in the photo exhibits the classic “O” sign. If his tongue makes it a “Q.” be advised to begin resuscitation immediately.

  6. My thinking runs along Anna’s lines except I would add depression to the list. Both weight gain and sleep problems are associated with clinical depressive episodes. Although you run into a bit of a chicken-egg problem there.

    Dr. J – will you please come to my next birthday party?? 😉

  7. I concur; when I was put on an antidepressant that also helped me sleep, I finally realized that the quality of sleep I had been getting for *years* was terrible, even though I was sleeping eight to ten hours at a time. Now I wake up and have energy; I don’t crave simple sugars in the morning and I don’t need naps in the afternoon. Making healthy lifestyle changes doesn’t seem so difficult. I’m looking forward to getting back into weightlifting.

  8. “as perimenopausal and menopausal hormonal shifts can negatively impact sleep quality and duration, and both are associated with weight changes, for instance”

    This one here seems to be my issue currently and I do not know where to go with it! Sleep has been disrupted the last few weeks and I appear to have put on a bit of weight as well, along with other symptoms. It sucks but I do not want to resort to meds. Thoughts???

  9. I think I’ll agree with Barry’s assessment, the result seems obvious. People who sleep short amounts of time eat more often and people who sleep 9+ hours *probably* aren’t that active in the day (I don’t know anyone who has that much time to sleep on average who isn’t seriously ill). I think the sleep patterns are not the cause of the weight gain but more of a result of other factors.

    For the fitness-minded people the only reason I can see weight gain to occur if sleeping too much is that you’re in “starvation” too long. I knew some bodybuilders a few years ago who’d sleep 10 hours a day (often chemically assisted) but they would wake up at least once to eat in the middle of the 10.

  10. Correlation is not cause. Taubes has a plausible hypothesis that fatigue, excessive hunger, and obesity are symptoms of celluar starvation that stocks the fat cells at the expense of other body cells. So it makes sense that people whose body cells are starving would need more sleep.

    I don’t have much to say about the correlation between less sleep and weight gain, other than to note that medications, clinical depression, and other factors might affect both insulin (the primary weight gain hormone) and sleep.

  11. For about a decade (to age 44), increasingly I would wake in the night for no apparent reason and not be able to get back to sleep, which exhausted me during the day to the point that I dropped any responsibility & chore that wasn’t absolutely essential. I absolutely wasn’t burning the candle at both ends, but I felt like I was.

    I also used to wake suddenly and sit bolt upright with repeated violent “coughing fits” (I didn’t have any major allergies or respiratory infections), which would then keep me – and my husband- awake for hours. Sleeping in a semi-upright position sometimes was effective, but the sleep quality wasn’t ever very good. Dealing with the dust, allergen coverings for bedding, and nasal steroids didn’t help, because that wasn’t the problem. So we lived with it.

    Everyone is different, of course, but my sleep quality and duration improved nearly 100% when I got on an appropriate dose of thyroid hormone treatment almost two years ago. After a lot of reading and keeping a symptom diary, I perservered and finally found patient and informed practitioners who didn’t write Rx just to mask symptoms. I’m finally sleeping well nearly every night, which makes everything better in the day (and without resorting to sleeping pills, anti-depressants, and various other drugs my former internist wanted to prescribe).

    I had at least 10 or more years of undiagnosed mild hypothyroidism, but during that time, I never imagined anything systemic like that. I just noticed an increasing number of very annoying but seemingly unrelated changes in all sorts of things minor and major, that my (former) internist attributed to “getting old”. She told me to get used to getting old because the body wasn’t designed to thrive past age 50 (I had just turned 44 – I’m not into age-denial and anti-aging, but that attitude is such BS!).

    It took trying several doctors over several months to get treated in a way that produced both “good” lab results and me feeling better, finally going outside my HMO network to a recommended doctor and paying out of pocket. Too many doctors treat the lab results and not the patient. When some symptoms do not resolve even when the “labs look great”, out come the anti-depressant samples and the Rx pad. Finding the right care was difficult, lengthy, and not covered by my HMO insurance plan, and frankly, the search was more depressing than the hypothyroidism itself. But two years later, I know my tenacity was well worth it. My increasing fatigue had been taking a high toll on my family.

    My husband was the first to notice that I no longer woke up coughing after my hypothyroidism was stabilized. I take T4 along with with a small dose of compounded natural thyroid extract for small dose of T3 – about a 98% T4 to 2% T3 ratio. Now I realize I was probably experiencing sleep apnea (though I do not fit the typical sleep apnea profile in any way, except for hypothyroidism, which isn’t a well known cause). The coughing problem has returned sporadically each fall for the last two years (some other symptoms also return around that time) so my doctor raises my dose a bit for the fall-winter season then reduces it in the late spring. That takes care of it. He has noticed the seasonal/declining light connection in other patients, too.

    I also noticed a bit more sleep improvement when I started on bioidentical progresterone about a year ago (I’m now 46) in the luteal phase of my cycle. But mostly I use progesterone for other not-serious-but still-annoying peri-menopause symptoms, like cycles that had shortened to 20 days on average, luteal phase itching and rashes, and worsening pre-menstrual breast pain. I now see a great gynecology Nurse-Practioner who is well-versed in bio-identicals and compounding. I wish I had found her years ago.

    The symptoms women experience often are so common and overlap with so many conditions; it is not always easy to determine the exact cause or combination of causes. Not enough practitioners are interested in doing more than manage symptoms instead of determining the root cause. Thyroid issues are more common in women (though men sometimes have a hard time getting thyroid problems diagnosed because of this), and typically occur during periods of reproductive hormone changes, such as the teenage years, post-childbirth, but especially pre-and post-menopause, which can last for many years. And being the “master hormone”, when the thyroid hormones are not working properly, the other reproductive hormones may not function properly, either.

    Plus, some hormones naturally decline with age, but they don’t always decline smoothly and predictably. I don’t have some of the typical pre-menopausal symptoms, like hot flashes (in fact I was so chronically cold for so many years I would have gladly welcomed a hot flash) plus I know from two rounds of complete hormone testing in my 30s that my estrogen levels weren’t ever going very high and roller-coastering down (the rapid, steep estrogen fluctuations cause hot flashes); increasing an-ovulatory cycles and low progesterone production were much likely to be my problem.

    What helped me might not solve every woman’s sleep disturbances, but with so many friends in their 30s and 40s also experiencing debilitating sleep disturbances, thyroid and hormone levels would be first things that should be thoroughly investigated. Doesn’t mean every hormone shift or imbalance needs treating, either, but it’s useful to know what is and isn’t happening so the right decisions for treatment (or no treatment) are considered. For instance, I would probably would have created more problems for myself if I had been trying the popular OTC estrogen-boosting supplements. And long-term untreated hypothyroidism can be serious, with increased risk of heart disease and other conditions.

  12. There is probably more than just correlation here and the results are not silly.

    Sleep deprivation (even mild deprivation) leads to increases in the hormone gherlin which is responsible for increases in appetite. At the same time, levels of leptin decrease following sleep disruption. Leptin is a hormone that leads to satiety. Disruption of sleep of otherwise normal sleeping adults has been shown to create the “munchies” often resulting in 500 kcal increase in consumption following day. Even 60-90 minutes of disruption can lead to this increase and people tend to go for salty, processed carbs. The hormones appear to be largely responsible.

    Not sure about the biological cause of over-sleeping as it relates to weight gain.

    I will say that over-sleeping for one person may be under sleeping for another. The “average” person does need about 8 hours of sleep. However, approximately 15% of the population has an optimal sleep need of only about 6 hours. Eight hours is over-sleeping for these people. On the side of the bell curve, there is about 15% of the population who has a sleep need of 9-10 hours, optimally speaking. Sleeping 8 hours for these people will lead to mild, chronic sleep deprivation. I do not see where this study accounts for this natural variation.

    Last, sleep quality does have a lot to do with the equation. It may be that many people who sleep more than 9 hours due to depression, boredom or just plain old fatigue may not be getting enough stage 3 and 4 sleep. Many people try to compensate for poor quality by increasing sleep time, but it does not work very well. Decreases in time spent in stages 3 and 4 may very well lead to the hormone disruptions noted above.

  13. I’m a 9-10 hour person (since I was little), sometimes I’ll go longer if I feel like it. I do have the kind of lifestyle that allows me to sleep as long as I want to, mostly because I’ve chosen that kind of lifestyle intentionally. I have few responsibilities beyond the basic bill-paying & house-cleaning (and a part time job), so I happily indulge in sleeping as much as I want to. So there are people who are not “seriously ill” and do have time to sleep that much.

    I would argue that many of the people who think they don’t have time to sleep simply aren’t choosing to sleep. Time spent watching TV & reading blogs could be spent sleeping, but most people would rather stay up so they don’t “miss anything”. I know there are people who are truly busy, but most of us have more of a choice to sleep than we think. I know how much I love to sleep, so I make choices that accommodate that desire.

    I don’t think sleeping so much is detrimental to my life at all. I find I eat way less when I sleep more for a few reasons. I feel rested & emotionally stable, so I don’t eat junk because I’m cranky. I plain just can’t eat while asleep, and I have less hours in the day to eat. This also leads to unintentional IF-ing because by the time I’m showered & ready it’s nearly lunchtime, might as well wait & just eat lunch in an hour or two.

    Lots of sleep = laziness = poor food choices doesn’t ring true for me. The more I sleep, the better my food choices are. Not everyone who sleeps a lot is just lazy or bored. And for that matter, some of the laziest people I know don’t get much sleep, and I wonder if they’re lazy because they’re tired all the time.

    Overall I figure that if my body didn’t wake up naturally then obviously I needed to sleep. Forcing myself to wake up early has only led to crankiness & muscle soreness. There’s nothing wrong with sleeping a lot & enjoying it, provided other areas of life don’t suffer for it. Some people act like it’s a sin to sleep until noon, but I think it’s far worse to neglect your body because there’s some societal rule saying “sleep = lazy” and no one wants to be seen as lazy.

  14. Heather,

    I think you make some great points. I sometimes will lay down and rest my eyes, but rarely can nap (if I do it messes with my night sleep, too).

    My husband is like you; he will sleep a lot if he can arrange it in his schedule. He is pretty much his own boss; he goes into work late several times a week to have a little nap in the morning and also on weekends. His work is such that he can do a lot at home, too. That was hard for me to adjust to at first, but denying my husband a nap a few times a week and trying to keep him on a conventional work schedule just made both of us cranky and annoyed.

    Sleeping isn’t a moral thing. It’s responding to and respecting individual needs.

  15. Thank you, Anna. Your last line is exactly how I feel. In the past I’ve felt like I was being “bad” somehow or should feel guilty for sleeping a lot, like there was something wrong with me or I didn’t deserve to waste time sleeping.

    Since living with my husband (9 years now) I’ve gotten over that because he’s never acted like my sleeping is a bad thing, and encourages me not to feel bad about it. He’ll even tell me to take a nap if he can tell that I’m in a bad mood or have a headache.

    I’m really grateful for his understanding & accepting attitude, even though he rarely sleeps more than six hours a night. I’m sure your husband is as grateful as I am. =)

  16. Hmmmm, well, this sounds interesting. I usually sleep about 8-9 hours during the week, and 10 hours or more on the weekend. Though I can’t say this has had an effect on my weight or anything. :/

  17. I think it is interesting to note that teenagers often require more sleep than adults and that the amount of sleep needed is different for different stages of life as well, usually decreasing with age.

    Circadian rhythm is also important. For example, perhaps those that slept too little or too much slept at different times of the day or in broken rhythms than the 7-8 hour sleepers? The number of hours don’t indicate the intervals.

  18. this is all so very true! I been on cpap for a year now .
    I have lost 50 pounds walking and trying to be more active and eating what i thought was healthy ..
    since I have found this site and made the Primal change for life my a1c has come down. I feel great and am getting stronger everyday ! my sugar is more stable throught the day and I dont have those crazy cravings for junk !
    I been eating about 2000 cals a day and feel full and satisfied. I am losing weight too! grainless and sugarless is so much better. however I will have that once in a while low fat sub .
    keep on Groking ! 🙂