Researchers have discovered the “magic number” for weight loss.
—By Deborah Kesten
For millennia, humans awakened with the light of day and went to sleep when it got dark. During the twentieth century, 24/7 access to electricity and electronics made it possible for us to change our sleep cycle with the flip of a switch. Add a too-much-to-do, too-little-time-to-do-it lifestyle, and you have an equation for sleeping less and weighing more. Can a change in the number of hours you sleep each night make a difference in how much you weigh? Some studies are suggesting this may be so, because unwanted weight may be a consequence of stepping away from the sleep cycle that sustained, rejuvenated, and healed humans for so long.
Counting Zzzs
Are you really more prone to put on pounds when you don’t get enough sleep? Absolutely, says Sanjay Patel, lead investigator of a study that added the issue of inadequate sleep to the obesity landscape in 2006. To come to this unexpected conclusion, Dr. Sanjay R. Patel, of the Division of Pulmonary and Critical Care Medicine, Case Western Reserve University, and his team conducted the largest-ever sleep study of its kind. Starting in 1986, they undertook a 16-year study that would track the sleep habits of almost 70,000 middle-aged women nurses. But they did more than merely observe sleep routines: the researchers linked the number of hours each woman slept each night to her weight over time.
What Patel found was remarkable: about 33 percent of the women who slept five hours or less per night each gained thirty-three pounds or more over the course of the study, while an additional 15 percent gained even more and became obese. In comparison, 12 percent of the women who slept one hour longer each night—an average of six hours—were also likely to gain weight, but less so: only 6 percent become obese. And then the good news emerged: those who typically managed seven hours or more nightly gained the least weight.
Patel’s study yielded three especially intriguing insights. The first is that the sleep less/weigh more link was there when the study started: women who slept five hours or less nightly already averaged about 5.4 pounds more in weight than those who managed at least seven hours each night. The second finding further verified the connection, in that over a ten-year time span, the more sleep-deprived women gained an average of 1.6 pounds each year. While this may not seem like much, over a period of ten years it could mean sixteen added pounds—or, if the trend held, a gain of thirty-two pounds over twenty years. The third insight is the bottom line of Patel’s study: women who sleep five hours or less each night are 32 percent more likely to put on weight than those who sleep seven hours or more.¹
Fact or Fiction?
Were Patel’s findings a fluke? Or did his sixteen-year study uncover a new clue about why so many of us find it difficult to lose weight and, if we do, to keep it off? Over the next few years, several good studies on the sleep-weight connection, conducted with all age groups in several countries, confirmed Patel’s findings: there is a correlation between how much you sleep and how much you weigh. But the lesson of the sleep-weight link suggests even more: the mind-body is exquisitely sensitive to the quality of sleep. Sleeping too little, too much, or just enough may create chemical changes throughout your mind-body that tip the weight scale up . . . or down.²⁻⁴
The sleep more/weigh less formula may seem simple, but a closer look reveals the picture isn’t quite so black and white. Population-based sleep studies such as Sanjay Patel’s 16-year project don’t establish definitively that lack of sleep causes obesity. In the world of science, what it suggests is a correlation between insufficient sleep and weight gain. Still, the dozens of sleep-weight studies that have been done with different populations in many countries tell us that the link between lost sleep and obesity isn’t likely to be just a coincidence. It’s a fact.
The Sleep Less Life
If you find it difficult to get to sleep or to stay asleep, you have a lot of company: about seventy million Americans are affected by chronic sleep loss.⁵ In fact, insufficient sleep is a growing problem in modern society. Over the past fifty years, the average number of hours we sleep each night has decreased by two hours; and from 1998 to 2005, the percentage of those getting eight hours of sleep dropped from 36 percent to 25 percent.⁶
There are lots of reasons for not getting enough sleep. When you go to bed, do you worry about work, say, or money? Or do you watch TV or surf the Web well into the wee hours? Not only may such behaviors make you anxious or depressed, but light from TV and computer monitors that stimulate the brain can also wreak havoc with your natural sleep cycle. Or perhaps you’ve developed a full-blown sleeping disorder, such as insomnia, which occurs when you find it hard to fall or stay asleep throughout the night.
Sleep Strategies
Sleeping well is a necessity if you want to lose weight and keep it off. Here, ways to work on the problem of too little sleep.
- Identify how much sleep you need. The American Academy of Sleep Medicine recommends that most adults get between seven and eight hours of sleep each night.⁷ This range also fits into Sanjay Patel’s study, which showed that women who sleep seven hours or more are less likely to be overweight.¹
- Figure the best time. To increase your chances of getting seven and a half hours of sleep nightly, write down the time you typically wake up in the morning. Then count backward seven and a half hours. For instance, if you usually wake at 7 am, seven and a half hours earlier would be 11:30 pm. This is the best time for you to go to sleep to ensure yourself of seven and a half hours of sleep each night.⁸
- Be caffeine-free after lunch. Caffeine from soft drinks, coffee, tea, chocolate, or other beverages and foods can stay in your system hours after you’ve consumed it. To “de-stimulate” well in advance of your sleeping time, avoid consuming caffeine-containing products after lunch.
- Discover the light side of dark. Exposure to light while sleeping can cause levels of the sleep-friendly hormone melatonin to decline quickly. This can interrupt the sleep cycle, even if you don’t awake fully. Make your bedroom as free of light as possible with dense curtains and alarm clocks that don’t directly “glare” at you. Consider wearing an eye mask that blocks out light.
- Sip something soothing. Try naturally relaxing herbal teas to enhance sleep. Some have a calming effect on the nervous system: lemon balm, lavender, linden, chamomile, valerian, and passion flower.
- See a sleep specialist. For many, changing their nighttime habits and practicing good sleep hygiene gives them the rest-filled sleep they want. For others, such strategies may not be enough. You don’t have to continue suffering if sleep problems persist. Instead, see a sleep doctor. These specialists are trained to pinpoint the cause of your sleeplessness and will work with you to find the remedy. They can help you with a weight-loss plan as well, if needed, because obesity is often linked with sleep issues.
Sleep More, Weigh Less
Plenty of weight-loss products promise miracles. I recall one in particular that promised a magic pill to let you lose weight while you sleep. But you don’t need a mystical (and questionable) potion to lose weight while sleeping, because adequate sleep, itself, is the solution you’re seeking.
The takeaway: To increase the odds of losing weight and making weight loss last—sleep soundly—between seven and eight hours each night.
In addition to keeping weight off, getting enough sleep may prevent or at least, better manage, other health problems—from blood pressure and mood to diabetes and more.⁹ Given such benefits, sleep is a necessity, not a luxury.
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References:
- S. R. Patel, A. Malhotra, D. P. White et al., “Association between Reduced Sleep and Weight Gain in Women,” American Journal of Epidemiology 164, no. 10 (2006): 947–54.
- G. Hasler, D. J. Buysse, R. Klaghofer et al., ”The Association between Short Sleep Duration and Obesity in Young Adults: A 13-Year Prospective Study,” Sleep 27, no. 4 (2004): 661–6.
- F. P. Cappuccio, F. M. Taggart, N. B. Kandala et al., ”Meta-Analysis of Short Sleep Duration and Obesity in Children and Adults,” Sleep 31, no. 5 (2008): 619–26.
- S. Taheri, “The Link between Short Sleep Duration and Obesity: We Should Recommend More Sleep to Prevent Obesity,” Archives of Disease in Childhood 91, no. 11 (2006): 881–4.
- U.S. Department of Health and Human Services: National Institutes of Health, National Heart, Lung, and Blood Institute, “Your Guide to Healthy Sleep,” NIH Publication No. 06-5271, November 2005, http://www.nhlbi.nih.gov/health/public/sleep/yg_slp.htm (accessed February 16, 2012).
- G. Jacobs, The National Sleep Foundation’s 2005 Poll, March 29, 2005, http://www.talkaboutsleep.com/sleep-disorders/2005/04/insomnia-nsf-poll.htm (accessed February 17, 2010).
- American Academy of Sleep Medicine, “Sleep Evaluation,” http://www.sleepeducation.com/SleepEval.aspx (accessed February 16, 2012).
- Healthy Living, “Dr. Oz’s BIG Sleep Tips,” Huffington Post, February 13, 2012, www.huffingtonpost.com/dr-mehmet-oz/dr-ozs-big-sleep-tips-vid_b_422243.html (accessed Feb. 13, 2012).
- Institute of Medicine, “Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem” (Washington, DC: The National Academies Press; 2006).