Getting seven to eight solid hours of sleep each night might seem an almost impossible luxury to many people. But not getting enough sleep is known to impair mental function and increase the risk for heart disease, among other ill effects. Accumulating evidence also suggests that even short-term, partial sleep deprivation could pave the way for weight gain and other negative metabolic consequences.

More than 28 percent of adults in the U.S. report that they get less than six hours of sleep a night, with this cumulative deprivation becoming more common in the past three decades. And now that more than 35 percent of U.S. adults are currently obese, researchers have been searching for potential links between the two conditions, in hopes of reducing the increasing health and economic burden of obesity. Establishing lack of sleep as a risk factor for weight gain could have important clinical and public health effects, possibly allowing people to make simple lifestyle changes to improve their metabolic health.

A new report, published online October 24 in the Journal of the Academy of Nutrition and Dietetics, reviews 18 carefully controlled laboratory studies that tested human subjects' physiological and behavioral responses to sleep deprivation as they relate to metabolic health.

Reena Mehra, an associate professor of medicine who studies sleep and health at Case Western Reserve University School of Medicine and who was not involved in the new analysis, notes that the new paper is "a well done review of the experimental data."

The researchers found that studies of people without sleep-related conditions who got consecutive nights of four to six hours of sleep revealed a wide range of negative effects involving appetite hormone signaling, physical activity, eating behavior and even fat-loss rates. "From a population health perspective, this helps to get people to understand that sleep deprivation really does have an impact on your health," Mehra says.

To sleep, perchance to eat less
Perhaps some of the best-documented effects of sleep deprivation on weight are based on two powerful hormones: ghrelin and leptin. Ghrelin is involved in sending hunger signals and leptin helps to tell you that you are full. In one study, after just two consecutive nights of four-hours' sleep, test subjects had a 28 percent higher ghrelin (hunger) hormone level and 18 percent lower leptin (satiety) hormone level in their blood compared with subjects who had spent 10 hours a night in bed. In the same study, for those who were sleep deprived, "self-reported hunger and appetite ratings significantly increased by 24 percent and 23 percent, respectively," noted the authors of the review paper, which was led by Julie Shlisky, a researcher at The New York Obesity Nutrition Research Center at Saint Luke's-Roosevelt Hospital Center. "The greatest increase in appetite rating was for energy-dense, high-carbohydrate foods," Shlisky and her co-authors noted. Other studies found additional increases in fat and saturated fat consumed by those suffering from sleep deprivation. One study also found a change in another eating signal called peptide YY, which is thought to tell the body it is full after eating enough. It dropped off in a group of subjects who had been allowed only five hours in bed for two nights, suggesting that these sleepy subjects would be more inclined to eat more given the opportunity.

10 Comments

1. 1. Pazuzu 04:44 PM 10/25/12

   This is interesting. As an older, retired person whose diurnal cycle has gone through changes, I have noticed how much harder it is to keep the weight off despite regular exercise. The changes in sleep may be part of it.
   
   I am intrigued by the author's reference at the beginning of the article to "solid sleep." According to David Randall's book "Dreamland," there's evidence that the "natural" (that is, before the invention of the electric light bulb) sleep cycle is segmented into a "first sleep" and a "second sleep," with an hour or two between segments. Now that I can sleep without the need to get up by a particular time, I definitely find myself sleeping that way, with a total average of about seven hours.

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2. 2. PGibbs 07:44 PM 10/25/12

   All this evidence and yet we wonder why there is an epidemic of obesity? Hasn't anyone ever thought to correlate the trend to push more and more people into shift work with its negative effects on sleep with obesity over time and large scale geographic areas? Why don't we outlaw shiftwork? It leads to car accidents, heart attacks and weight gain. Where are the insurance companies? They stand to gain if these problems are solved and they have the financial muscle to force other industries to reduce or eliminate shift work and improve health and accident rates.
   

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3. 3. S. N. Tiwary 10:29 AM 10/26/12

   Connection between sleep and obesity is intriguing. Sound sleep reflects wellness. Wellness reflects smartness. Smartness reflects non-obesity. Thus, there is a very strong relationship between sleep and obesity.
   S. N. Tiwary
   Director, Former V. C. (Acting)

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4. 4. Elegia 09:34 PM 10/26/12

   Getting more sleep might seem a "simple" solution to the issues of weight gain and mental absence; but for many people these days, working two (or MORE) jobs in order to keep their families' heads above water, sleep has become optional.
   
   Not only the wealth, but the HEALTH, of the populace always suffers when feudalism reigns.

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5. 5. jackvandijk 05:31 PM 10/28/12

   Well, I sleep eight hours per night and I feel well. To bed at ten and up at 6. Occasionally but seldom watch a movie till eleven or come home late on Saturday night, but sleep out on Sunday morning. Why not arrange your life aroun sleep?

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6. 6. leoluca criscione in reply to Pazuzu 05:06 AM 11/1/12

   Dear "Pazuzu". "As an older, retired person", your problem with the regulation of body weight is related to the DECREASED Resting metabolic rate.... Read more here GOOD APPETITE from Switzerland.... http://www.vitasanas.ch/wp/wp-content/uploads/2012/09/BOOK5_Resting_Metabolic_Rate_RMR.pdf
   

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7. 7. leoluca criscione 05:11 AM 11/1/12

   FINALLY a weight gain is correlated with an ENERGY (Calories) intake greater than the PERSONAL DAILY CALORIC REQUIREMENT (PDCR) ! It is obvious, that less sleep means MORE time to eat... Read more abaout PDCR with the link below! http://www.vitasanas.ch/fileadmin/user_upload/pdf/BOOK4_The_personal_caloric_requirement__2_.pdf
   

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8. 8. leoluca criscione 05:26 AM 11/1/12

   " One study also found a change in another eating signal called peptide YY"!! We published 1996 a paper in "Nature" about the KEY role of the NPY (of the PEPTIDE YY family"). http://www.nature.com/nature/journal/v382/n6587/abs/382168a0.html
   In 2002, the PHARMA-Company in which the discovery was made (NOVARTIS, BASEL) STOPPED all activities on obesity research just because the "body is smarter"!!!! See more in the book "eating healthy and dying obese" http://www.vitasanas.ch/wp/?page_id=370
   
   See also chapter in the book about "Science feeds the confusion"!! http://www.vitasanas.ch/fileadmin/user_upload/pdf/BOOK-chapter_1_confusion.pdf

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9. 9. leoluca criscione in reply to jackvandijk 05:47 AM 11/1/12

   MUCH better to ARRANGE your LIFE around your LIFE NOT youe sleep! ENJOY LIFE! Science cretes many time ONLY confusion... I am a scientist!!!!

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10. 10. Raghuvanshi1 06:51 AM 11/2/12

    Every man is unique so this kind of statistical survey how much useful?How much sleep require is depend on every man on his gene, his upbringing,there are many factors are responsible for man`s obesity , so draw a conclusion only for sleep is futile

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