Sleep and Body Weight: A Close Relationship

“If you weigh too much, maybe you should try sleeping more.”

This commentary in the journal Sleep caught my eye. Flip as it sounds to a person who would sleep more if she could, it points to a relationship between sleep and body weight that should be widely publicized.

Sleep can also affect your ability to keep weight off. As for the relationship between insomnia and body weight, the latest news is surprising. Read on for details:

Insomnia with short sleep increases susceptibility to overweight“If you weigh too much, maybe you should try sleeping more.”

This commentary in the journal Sleep caught my eye. Flip as it sounds to a person who would sleep more if she could, it points to a relationship between sleep and body weight that should be widely publicized.

Sleep can also affect your ability to keep weight off. As for the relationship between insomnia and body weight, the latest news is surprising. Read on for details:

Sleep Deprivation and Weight Gain

It’s established now that sleep deprivation increases feelings of hunger (or interferes with feelings of satiation). Sleep deprivation occurs when sleep is arbitrarily restricted—as it might be during a research project in a sleep lab, when participants’ sleep is restricted to 4 hours a night—or when work or family responsibilities keep you from getting the sleep you need. Either way, the tendency is to eat more. And the more you eat, the more weight you gain.

People who are chronically sleep deprived don’t only tend to put on weight. They also risk developing metabolic syndrome, which is linked to serious medical problems like heart disease and diabetes.

So if the bathroom scale is inching upward every time you weigh yourself, consider not just changes to diet and exercise but also allowing more time for sleep if—and this an important caveat—you’re actually able to get more sleep. A mere 30 minutes more sleep a night can help with weight loss and greatly improve your long-term health.

Short Sleep and Body Weight

People who are short sleepers by nature—those who routinely sleep less (sometimes quite a bit less) than 6 hours a night—are also more susceptible to weight gain and obesity than those whose nights are longer. A study conducted over a period of 13 years showed that every extra hour of sleep duration was associated with a 50% reduction in risk of obesity.

Short sleep is also associated with impaired glucose tolerance and insulin resistance. Thus short sleepers are more at risk for developing diabetes as well.

Sleep Duration Is Not the Whole Story

But routinely shortened sleep is not the only sleep issue associated with weight problems. Research is showing now that sleep quality is related to the ability to lose weight and keep it off.

Unlike sleep duration, which can be objectively measured with polysomnography, sleep quality cannot be assessed objectively. So it’s typically measured with questions similar to these:

  • Do you regularly have trouble sleeping?
  • What’s the overall quality of your sleep?
  • How often do you experience a sense of well-being during the day?

One recent study found that better sleep quality and being a “morning person” correlated with successful weight loss maintenance. Compared with current enrollees in a weight loss program, people who’d lost at least 30 pounds and kept the weight off for at least a year reported significantly better sleep quality and were more often early risers.

In another study, investigators compared people who maintained a loss of at least 10% of their body weight to people who regained their lost weight. Men (but not women) who were successful at shedding pounds and keeping them off reported significantly better sleep quality (but not more sleep) than the weight regainers.

Do Insomniacs Typically Have Weight Problems?

Not necessarily, if results of the latest study can be believed. Researchers in Germany compared the body mass index (BMI) of 233 patients with “severe and chronic insomnia . . . showing objectively impaired sleep quality” to the BMI of 233 age- and gender-matched good sleepers. The results were surprising:

  • BMI, insomniacs: 23.8 kg/m2 (The “normal” BMI range is 18.5 to 24.9.)
  • BMI, good sleepers: 27.1 kg/m2

On average, the chronic insomniacs weighed significantly less than the good sleepers. If confirmed by other research, the result should be somewhat reassuring to those of us concerned about the consequences of insomnia. It would also lend support to the idea that insomnia has less to do with insufficient sleep than with excessive arousal (or hyperarousal) that may affect us 24/7.

Do you find yourself eating more after a couple bad nights?

“Sleep Was Easier to Give Up Than the Job”

Several people I interviewed for The Savvy Insomniac blamed their insomnia on stress at work. A trial lawyer attributed his nighttime wake-ups to “mostly job related stress.” A 52-year-old woman on Social Security disability saw her insomnia as resulting from 14 years of shift work as a dispatcher with emergency services.

Work can interfere with sleep in many ways, including shortening sleep duration. The CDC has just released a report on the categories of work most likely to shorten people’s sleep. Here’s what they are and how they may relate to chronic insomnia.

Persistent trouble sleeping can develop from years of shift workSeveral people I interviewed for The Savvy Insomniac blamed their insomnia on stress at work. A trial lawyer attributed his nighttime wake-ups to “mostly job related stress.” A 52-year-old woman on Social Security disability saw her insomnia as resulting from 14 years of shift work as a dispatcher with emergency services.

Work can interfere with sleep in many ways, including shortening sleep duration. The CDC has just released a report on the categories of work most likely to shorten people’s sleep. Here’s what they are and how they may relate to chronic insomnia.

Occupations Associated With Short Sleep

The findings are based on surveys conducted on working adults in 2013 and 2014. By telephone, workers answered questions about the kind of work they did and how much sleep they normally got in 24-hour period. In all, the CDC analyzed the responses of nearly 180,000 people. The data show a high percentage of workers in these five broad categories typically slept less than 7 hours a night:

  1. Production (printing workers, plant and system operators, supervisors, and production workers), about 43%
  2. Healthcare Support (nursing, psychiatric, and home health aides), about 40%
  3. Healthcare Practitioners and Technical (health technologists and technicians, health diagnosing and treating practitioners), about 40%
  4. Food Preparation and Food-Related (supervisors, food preparation and serving workers, cooks), about 40%
  5. Protective Service (fire fighting and prevention workers, law enforcement officers), about 39%

Occupations Involving Shift Work

The jobs in all five categories often involve shift work. Round-the-clock operations in hospitals, factories, restaurants, and police and fire departments make it necessary for some employees to work at times when we’re normally at rest. In other work situations employees regularly rotate from one shift to the next.

Shift work is known to interfere with sleep, contributing to shortened sleep and excessive sleepiness. It disrupts circadian rhythms and has a negative effect on health, contributing to a rise in certain cancers, obesity, and impaired glucose tolerance. It also increases the risk of injury.

Could Shift Work or Work-Related Short Sleep Lead to Chronic Insomnia?

Lynda, the retired dispatcher on disability, felt there was a direct link between her insomnia and her work in emergency services. Day jobs she’d held previously gave her “no trouble sleeping at night.” But the dispatch job was different:

I really do believe that the shift work was a major contribution to my sleeping problems. I base this on comparisons with my coworkers. I don’t know any policeman, fireman, or dispatcher who didn’t have trouble sleeping while swinging shifts on a regular basis. I loved this line of work because it was always rewarding to be able to help someone, or be responsible for saving someone’s life. Sometimes, depending on the size of the catastrophe, it could be very intense. You could feel the adrenaline pumping. . . . It just gave you a great feeling knowing that YOU were the one who made a difference. I guess that would explain why I couldn’t sleep after coming off of working something major. Sleep was easier to give up than the job.

How It Could Happen

The neurocognitive model of insomnia suggests how chronic insomnia might develop from work-related stress and short sleep. In fact any stressful situation can trigger acute (or temporary) insomnia, including stress at work. But acute insomnia does not necessarily become chronic. Sleep can—and, in many people, does—return to normal once the situational triggers for insomnia get resolved.

But in the five categories of jobs identified by the CDC, less-than-perfect conditions of employment may be a given when you accept the job. Want to work in emergency services? Fine. You’ll work rotating shifts.

If you find this situation stressful because it interferes with your sleep, you may be tempted to resort to measures that often make sleep worse—using alcohol to get to sleep, for example, or spending long stretches lying awake in bed.

Lying awake in bed often leads to worry and rumination, and to high-frequency brain activity during sleep onset and beyond. Eventually you wind up conditioning arousal in your body and brain. Et voilà, you’re saddled with chronic insomnia—all because you were a good citizen and willing to work around the clock.

I never had an easy time working split shifts and I avoided other jobs that might disrupt my sleep. People like Lynda are more adaptable. But . . . at what cost?

If you’ve had a job that shortened or otherwise interfered with your sleep, how did you manage the situation, and were their any long-term effects?

Get Rid of Unfounded Ideas About Sleep

People sometimes ask whether chronic insomnia is mainly a physiological or a psychological problem. Often it’s both.

Certain beliefs about sleep can interfere with getting a good night’s rest. A reality check can help you sort out truth from myth, which in turn may help you sleep.

Insomniacs will sleep better if they're rid of erroneous ideas about sleepPeople sometimes ask whether chronic insomnia is mainly a physiological or a psychological problem. Often it’s both.

High reactivity to stress—whether strictly biological or due to a combination of biological and environmental factors—may predispose you to insomnia. But there’s probably a psychological aspect to the problem if insomnia is a persistent feature of your life.

Certain beliefs about sleep can interfere with getting a good night’s rest. A reality check can help you sort out truth from myth, which in turn may help you sleep.

I need 8 hours of sleep a night to function well.

If the National Sleep Foundation (NSF) recommends 7 to 9 hours of sleep for young and middle-aged adults and 7 to 8 hours for older adults, then it follows that 8 hours of shut-eye is the gold standard, right?

Not necessarily.

Sleep experts still haven’t figured out how to measure an individual’s sleep need. Prescriptions like the NSF’s are based on huge data sets containing information about sleep duration and longevity. The data, when graphed, fall into a U-shaped curve, with people whose sleep duration falls in the middle of the curve outliving those at both ends (i.e., the really short and really long sleepers).

Authors of recent analyses have concluded that it’s the 7-hour, and not the 8-hour, sleepers who live the longest. And in an early study involving data from over a million patients, people who slept 6.5–7.4 hours outlived the rest.

Keep in mind, too, that data on sleep duration in these big, retrospective analyses are usually based on subjective estimates, not on objective measures of sleep time. Finally, the recommendations on sleep duration set forth by the NSF panel are offered with this caveat: “some individuals might sleep longer or shorter than the recommended times with no adverse effects.”

You may think you need 8 hours of sleep based on personal experience. Especially if you’re not sleeping well, an 8-hour night can feel heavenly. But to assume you need 8 hours of sleep every night is a mistake.

There’s an average amount of sleep each of us needs for peak functioning. Normal sleepers, whose sleep periods are fairly regular, can estimate their sleep need pretty easily based on the time they drop off and wake up.

But insomniacs’ sleep is often erratic—2 or 3 bad nights followed by a good night—with the pattern repeating again and again. Sleep need on a given night is based on several factors: how long you’ve been awake, what you did during the day, and prior sleep. You may need 8 hours of sleep following several stressful days and short nights. But your average sleep need may be more like 6 or 6.5 hours a night.

I’m worried insomnia is going to do serious damage to my health.

Chronic insomnia is a risk factor for several nasty ailments: cardiovascular disease, depression, and fibromyalgia, to name a few. But saying something is a “risk factor” for something else does not imply causality. It simply indicates a correlation between one thing and another.

For example, if chronic insomnia is a risk factor for whiplash (it is), insomnia makes you more vulnerable to whiplash but does not indicate that you will develop whiplash. Even if you have chronic insomnia, the statistical probability of your developing whiplash is still relatively low.

Why scare the sleepless with talk of health problems we may or may not develop? Well, for years insomnia was dismissed as a trivial complaint without consequence. The fact that it has now been shown to have a relationship with other serious ailments makes it clear that insomnia is worthy of attention and treatment, and that insomnia research is worthy of funding. This is actually a boon for us.

All it takes is one bad night and my sleep is toast for the rest of the week.

If you’ve got chronic insomnia, it may be that sleeping poorly triggers anxiety about sleep, which in turn may make sleep more difficult the following night. Anxiety and worry are rarely compatible with sleep.

But as mentioned before, there’s an average amount of sleep each of us needs to function. You may not actually be aware of the amount you need, but your body IS aware of that amount. In fact, there’s a mechanism—the sleep homeostat—with a set point that keeps track of how much you sleep every night.

A bad night is going to register with the sleep homeostat as an inadequate amount of sleep. The result will be a greater build-up of sleep pressure the following night. Two bad nights will result in even greater pressure to sleep on the third night . . . and so on.

So while negative thoughts about sleep can prolong sleeplessness, an array of forces inside your body are actually working to promote sleep. They always win out in the end.

What ideas about sleep cause you the most anxiety?

Protein-Rich Dieting Helps Sleep

I’m not going to plug the high protein diet as the surest path to weight loss (although some say it is). But I do want to pass on the news that going on a high protein diet may be a path to better sleep, especially in people who are overweight or obese.

This is not just the conclusion of single study, which may or may not hold up over time. Rather, a protein–sleep connection has been documented in a handful of recent studies. If you’ve got insomnia and can afford to lose a few pounds, consider these results.

high-protein diet improves sleep qualityI’m not going to plug the high protein diet as the surest path to weight loss (although some say it is). But I do want to pass on the news that going on a high protein diet may be a path to better sleep, especially in people who are overweight or obese.

This is not just the conclusion of single study, which may or may not hold up over time. Rather, a protein–sleep connection has been documented in a handful of recent studies. If you’ve got insomnia and can afford to lose a few pounds, consider these results.

A Link Between Protein Consumption and Sleep Quality

Two studies were conducted by nutritionists at Purdue University. In a pilot study, they enrolled 14 overweight men and women, average age 56. Participants went on low calorie diets for 12 weeks. The percent of calories from protein in their daily diet varied in 4-week periods: either 10%, 20%, or 30%, in random order.

The upshot: Diets higher in protein significantly improved sleep quality (as measured by scores on the Pittsburgh Sleep Quality Index) regardless of whether the main source of protein was beef and pork or soy and legumes.

A total of 44 overweight men and women, average age 52, participated in the second study. Again, all participants went on low calorie diets. But this time, about half ate meals containing a typical amount of protein (the control subjects). Meals consumed by the other half were about twice as high in protein. At the beginning of the study, the sleep quality of both groups (as measured on the Pittsburgh Sleep Quality Index) was the same.

The upshot: By the end of this 16-week study, the group eating the protein-rich diet reported significantly better sleep quality than the controls.

The researchers conclude that “the consumption of a greater proportion of energy from protein while dieting may improve sleep in overweight and obese adults.”

A Quick Look at Sleep and Protein in Other Research

Other researchers have found a link between protein consumption and sleep.

Authors of a Korean study analyzed data from over 14,000 subjects ages 20–79 to see if dietary factors modified the association between sleep duration and obesity. The results showed that sleep duration correlated positively with protein consumption and negatively with carbohydrate consumption.

So along with weight loss here’s another reason to avoid pasta and fill up on fish: it might help you sleep longer.

College students were the focus of yet another study, this one looking at how dietary factors and psychological distress predicted sleep quality. Food choices that reduced the odds of poor sleep quality were

  • healthy dairy (by about 14%) and
  • healthy protein (by over 32%).

Once again, protein consumption is linked to better sleep.

The specific relationship between protein consumption and the sleep of people with insomnia has yet to be studied. But if you can afford to lose a few pounds and want to improve your sleep, try bumping up the protein and cutting back on carbs.

Make Sure It’s Healthy Protein

But make sure it’s healthy protein and not the bad stuff. Complete proteins, which contain all essential amino acids, are abundant in these foods:

  • meat (leaner cuts that are antibiotic and hormone free)
  • poultry (organic and cage free, if possible)
  • fish (wild is usually healthier than farmed)
  • eggs (from organic cage-free chickens, when possible)
  • dairy products

Incomplete proteins, which come from non-animal sources, are healthy choices, too:

  • nuts
  • seeds
  • beans
  • whole grains

If these are your main sources of protein, take care to eat them in combination with supplementary protein. Not just beans, but rather beans and brown rice.

Protein sources to avoid are fatty and processed meats such as bacon, sausage, deli meats, and hotdogs.

Are We Really Sleep Deprived?

People with insomnia typically worry about not getting enough sleep. It’s easy to understand why. The media are are full of stories warning of the perils of insufficient sleep: obesity, diabetes, dementia, cardiovascular disease.

But a study of sleep in 3 traditional societies published in October suggests that humans may need less sleep than we think we do—which should give insomniacs food for thought.

Insomniacs may not need as much sleep as they thinkPeople with insomnia typically worry about not getting enough sleep. It’s easy to understand why. The media are full of stories warning of the perils of insufficient sleep: obesity, diabetes, dementia, cardiovascular disease.

The Centers for Disease Control and Prevention for several years declared insufficient sleep to be a public health epidemic (last year they revised the language to “public health problem”). And according to an estimate set forth in Sleepless in America, a documentary released on the National Geographic Channel in December 2014, Americans sleep considerably less than we did 150 years ago.

But a study of sleep in 3 traditional societies published in October suggests that humans may need less sleep than we think we do—which should give insomniacs food for thought.

Making Inferences About Sleep in Times Past

How did people sleep millennia ago? Has electric lighting really had as negative an impact on sleep as sleep experts claim it has?

The scientists and anthropologists who conducted this study couldn’t travel back in time to assess the sleep of our ancestors. So they did the next best thing: study the sleep of 3 hunter–gatherer and hunter–horticultural societies in existence today. These traditional peoples, who live without electricity or any modern technology, live in equatorial regions of Tanzania, Namibia, and Bolivia.

What They Found Out

The investigators used wristwatch-type devices to measure sleep duration and light exposure for 94 adults over a total of 1,165 days. Following are some interesting findings:

  • People in these traditional cultures slept 5.7 to 7.1 hours a night—less than average sleepers in modern industrialized societies like the United States. Yet extensive research has found that although their daily energy expenditure is about equal to that of most Americans, they’re healthier and more physically fit than we are.
  • People did not go to sleep at sunset, as has been assumed about people before the advent of artificial lighting. On average, they went to sleep 3.3 hours after sunset, keeping vigil in the dark except for a small fire and moonlight. So electric lighting is probably not the only reason we like to stay up to watch the late show. Perhaps Thomas Edison did not have as big an impact on sleep as we think.
  • People got their sleep in a single sleep episode uninterrupted by long periods of wakefulness. Daytime naps were the exception rather than the rule. This challenges the idea that early humans had two separate sleep episodes interrupted by a wakeful period in the middle of the night, or that they routinely took daytime siestas.

Relevance to Insomnia

Many people with insomnia say they need 8 hours of sleep a night, and maybe some of us do. Yet although this study by itself is not evidence that we need any less, if it convinced us to revise our beliefs about sleep need downwards, it wouldn’t be a bad thing.

Sleep therapists say that one thing that happens to many insomniacs as their sleep improves is that they let go of the idea that 8 is the magic number. Sleep quality may matter more than the number of hours we get.

Why Such Alarmist Messages?

Sleep isn’t always seen as important—yet it is a pillar of health alongside diet and exercise. But the alarmist tone of some of the messages we hear about not getting enough sleep (“a public health epidemic”), and the fact that healthy sleep is almost always defined as a certain number of hours, is worrisome to people with insomnia and others whose nightly share of shut-eye falls short. How helpful are such messages really?

The cynic in me says the pharmaceutical companies and medical device makers are behind this campaign to insist that we aren’t getting the sleep we need. Because who stands to gain more from convincing us that we’re sleep deprived than the folks who sell Ambien and CPAP machines?

But Americans toward the end of the 19th century were also worried about their sleep. After the Civil War, many were moving off the farm and into the city, where life was more stimulating, and both faster paced and more sedentary, than on the farm. A widely held view was that civilization was evolving faster than the human organism could keep pace with, and good sleep was falling by the wayside.

Are we living in a similar climate today? Do the dire warnings about insufficient sleep fit in with general concerns about the pace of our 24/7 lives, and do they likewise reflect anxiety about social changes and/or fear that we can’t keep up?

I’d like to know what you think.

How Much Sleep Is Enough?

Getting 8 hours’ sleep a night is as healthful as eating 9 servings of fruit and vegetables and getting daily exercise—or so we’re told. In truth there’s no way to determine how much sleep any one of us really needs.

But the 8-hour recommendation is based on something, which is why we hear it so much. For those concerned about getting too little sleep, here are 3 ways to find out how much you’re actually getting.

Regarding sleep need, sleep quality may matter more than sleep durationGetting 8 hours’ sleep a night is as healthful as eating 9 servings of fruit and vegetables and getting daily exercise—or so we’re told. In truth there’s no way to determine how much sleep any one of us really needs.

But the 8-hour recommendation is based on something, which is why we hear it so much. Recent studies show “a strong association between nightly sleep duration and mortality risk,” Michael Grandner and colleagues say in a paper on sleep duration and health. Overall, people who report sleeping 7-8 hours a night live longer than people who report sleeping 9-10 hours and those who report sleeping 6 hours or less.

The same is true of the relationship between sleep duration and cardiovascular disease (and related conditions such as hypertension and diabetes). Short and long sleepers tend to be more vulnerable to these ailments than people who sleep 7-8 hours a night. Of interest to those of us with insomnia, short sleepers (who sleep 6 hours a night or less) with poor quality sleep have a much higher risk of developing cardiovascular disease.

Counting the Hours

If you’re concerned you’re not sleeping enough, consider the possibility that you may be sleeping more than you think. About 5 percent of insomniacs have “paradoxical insomnia.” Usually pretty energetic during the day, they feel like they sleep just a few hours a night. Yet polysomnography (PSG)—the test performed in a sleep lab—shows 7 or 8 hours of sleep-like activity going on in most of the brain. (I’ll explain this phenomenon in another blog.)

Many of us perceive the lightest sleep stage as waking. Up to 50 percent of the time, the brainwave patterns of insomniacs who undergo sleep studies look exactly the same as those of normal sleepers. So our perception of sleep does not always jibe with sleep as measured by PSG. And the while PSG cannot assess sleep quality, its assessment of sleep duration is important. People whose polysomnograms show they get considerably less than 7-8 hours’ sleep a night are the ones most vulnerable to cardiovascular disease and early death.

Objective Sleep Measures

Here are 3 ways to find out how much you sleep.

  • A sleep study. There are lots of downsides to going this route. It requires a doctor’s prescription, costs a lot, and is just a one-shot deal. Insomniacs’ sleep tends to vary a lot from night to night, and a sleep study is not going to provide information about your sleep duration over time, which is really what you want.
  • Actigraphy. This involves wearing a wristwatch-type device to bed for several nights. The actigraph assesses your sleep-wake patterns based on bodily movement. It’s fairly reliable most of the time. It also requires a doctor’s prescription.
  • Sleep-monitoring devices available without prescription. I’ve written about the Beddit, and a Google search will acquaint you with several others. These devices are relatively inexpensive, but none of them have been tested on insomniacs. They may not be sensitive enough to assess the nuances of insomniac sleep. (Coincidentally, just a few days after this blog post went out, Dr. Christopher Winter, who tested several sleep tracking devices on himself, posted a review of his findings in Huffington Post. It’s definitely worth reading if you’re considering buying one for yourself.)

Me personally? I know I’m a short sleeper but I’m not so concerned with racking up the hours. Health and longevity depend on several factors. Regarding sleep, I’m convinced that quality, and not quantity, matters more.

If you’ve undergone a sleep study or tried monitoring your sleep in some other way, what did you find out? Were you sleeping more—or less—than you thought?