Sleep Deprivation and Weight Gain

Sleep deprivation has become one for the most pervasive health problems facing people in the United States. It is estimated that people on average now sleep 90 minutes less per night than people did a century ago. Nearly a third of 1,000 participants in a 2002 “Sleep in America” poll said that they need at least eight hours to avoid feeling sleepy the next day. However, the participants responded that they averaged 6.9 hours of sleep on weeknights and 7.5 on weekend nights. Many Americans do not get the sleep they need and do not know the negative effects lack of sleep can have on their health and functioning.

According to Sleepdex – Resources for Better Sleep (Sleepdex.com), long-term consequences of sleep deprivation can include obesity. The link between obesity and sleep is an interesting one as lack of sleep can cause weight gain by increasing hunger and affecting metabolism, and extra weight can cause sleep disorders such as apnea which cause sleep deprivation.

Scientists have found that sleep deprivation increases levels of a hunger hormone and decreases levels of a hormone that makes you feel full, according to a USA Today article by Nanci Hellmich. The effects may lead to overeating and weight gain. This could explain why so many Americans who are chronically sleep-deprived also are overweight. And it could be part of the reason sleepy college students, new parents and shift workers pack on pounds.

Researchers say that getting enough shut-eye might be a critical component of weight control. And nutritionists one day might routinely advise dieters to “sleep it off” as well as to cut calories and increase exercise.

“We know the obesity epidemic is due to overeating – too big portions, too much rich food and too little activity – but why do we crave too much of these rich foods?” says Eve Van Cauter, Ph.D., a University of Chicago sleep researcher who is the lead investigator on one of the new studies. She says it's because “we are sleep-deprived and unable to curb our appetites.”

Sleep does indeed appear to be an important piece of the weight-control puzzle, says Stanford University sleep researcher Emmanuel Mignot, who also is releasing new research. If this is true, it might be part of the solution to the nation’s obesity problem. Sixty-five percent of Americans are overweight or obese, which increases their risk of heart disease, Type II diabetes, cancer and other diseases.

This percentage takes on a special significance when balanced against the fact that an estimated 63% of American adults do not get the recommended eight hours of sleep a night, according to the National Sleep Foundation. In fact, the average adult gets 6.9 hours of sleep on weeknights and 7.5 hours on weekends, for a daily average of seven hours.

Eve Van Cauter has spent 25 years doing research on the hormones that are affected by sleep. She says sleep deprivation activates a small part of the hypothalamus, the region of the brain that also is involved in appetite regulation. She is especially intrigued by, and has done several studies on, two critical hormones involved in regulating food intake: ghrelin and leptin.

They influence eating in different ways. Ghrelin is an appetite-stimulating hormone released mostly by the stomach. When ghrelin levels are up, people feel hungry, Van Cauter says. On the other hand, leptin, considered a satiety or fullness hormone, is released by the fat cells and tells the brain about the current energy balance of the body. When leptin levels are high, that sends a message to the brain that the body has enough food, and the person feels full, she says. Low levels indicate starvation and increase appetite. The hormones "have been called the yin and yang of hunger," Van Cauter says. "One is the accelerator for eating (ghrelin), and the other is the brake (leptin)."

Hungry for Sleep – and Food

Van Cauter, who directs the Research Laboratory on Sleep, Chronobiology and Neuroendocrinology at the University of Chicago School of Medicine, examined the effect of sleep deprivation on these two hormones for her latest study, published in the Annals of Internal Medicine. She had 12 healthy, normal-weight men, average age 22, come into a hospital laboratory to sleep, and eat dinner and breakfast.

On one occasion, they were limited to four hours in bed for each of two consecutive nights. At another time, they were allowed up to 10 hours in bed for two nights. Their blood was drawn at regular intervals, and they were asked about their hunger.

Findings:
  • Leptin levels were 18% lower and ghrelin levels were 28% higher after they slept four hours.
  • The sleep-deprived men who had the biggest hormonal changes also said they felt the most hungry and craved carbohydrate-rich foods, including cakes, candy, ice cream, pasta and bread. Those who had the smallest changes reported being the least hungry.

Link Found to Body Mass Index

Other research report similar findings. Scientists at the University of Wisconsin and Stanford University tracked 1,024 people ages 30 to 60. Participants from the Wisconsin Sleep Cohort Study took sleep tests and blood tests every four years and reported their sleep habits.

Findings:
  • People who routinely slept five hours a night had a 14.9% higher level of ghrelin and a 15.5% lower level of leptin than those who slept eight hours.
  • Those who regularly slept less than 7.7 hours had a slightly higher body mass index (BMI).

Research at Columbia University using government data on 6,115 people to compare sleep patterns and obesity found that people who sleep two to four hours a night are 73% more likely to be obese than those who get seven to nine hours. Those who get five or more hours of sleep a night are 50% more likely to be obese than normal sleepers. Those who sleep six hours are 23% more likely to be obese. And those who get 10 or more hours are 11% less likely to be obese.

Watch Your Sleep, Watch Your Weight

An article by Kelley Colihan in WebMD Health News states that researchers at Laval University in Quebec looked at 276 people for six years who were part of a larger Canadian study. Their sleep duration studies show the following findings:

  • Over six years, short sleepers (5-6 hours nightly) were 35% more likely to gain 11 pounds than average-duration sleepers.
  • Over the same time period, long sleepers (9-10 hours) were 25% more likely to gain 11 pounds than average-duration sleepers.
  • Short sleepers gained 58% more around their waists and 124% more body fat than the average sleeper (7-8 hours).

The American Academy of Sleep Medicine recommends that adults sleep between seven and eight hours a night. Study researcher Jean-Philippe Chaput of Laval University says people in the United States are losing sleep, with Americans sleeping one and a half to two hours less a night than we did 40 years ago.

Previous studies have shown similar findings linking a lack of sleep to creeping obesity. Researchers say this new study adds to a growing body of evidence showing a sleep connection to weight gain involving fluctuating hormone levels. According to the American Academy of Sleep Medicine, nearly a third of adults say they sleep less than six hours a night.

SLEEP DEPRIVATION CAUSES WEIGHT GAIN

The body is also stressed if it doesn't get enough rest. Sleep is another important part of the weight loss equation. If you aren't getting enough sleep, your body won't process glucose as well. Lack of sleep also raises cortisol levels. Sleep deprivation makes it more difficult to lose weight. A study by Eve Van Cauter at the University of Chicago showed that metabolism was slowed in people who were sleep deprived.

The study also showed that it was reversible with adequate sleep. The simple fix is to schedule the same amount of sleep every night. Find ways to relax before bed to maximize the number of hours you sleep each night

SLEEP DEPRIVATION IMPAIRS GLUCOSE TOLERANCE

Recent research by Eve Van Cauter, Ph.D., et al., also indicates that sleep loss may adversely affect glucose tolerance and involve an increased risk of Type II diabetes. In young, healthy subjects who were studied after 6 days of sleep restriction (4 hours in bed) and after full sleep recovery, the levels of blood glucose after breakfast were higher in the state of sleep debt despite normal or even slightly elevated insulin responses.

These findings were confirmed by the results of intravenous glucose tolerance testing. The rate of disappearance of glucose post injection – a quantitative measure of glucose tolerance – was nearly 40% slower in the sleep-debt condition, and the acute insulin response to glucose was reduced by 30%. Van Cauter’s research showed that less than 1 week of sleep restriction can result in a pre-diabetic state in young, healthy subjects. Multiple mechanisms are likely to mediate the adverse effects of sleep curtailment on parameters of glucose tolerance, including decreased cerebral glucose utilization, increases in sympathetic nervous system activity and abnormalities in the pattern of release of the counterregulatory hormones cortisol and GH.

Dreams of Good Sleep

Here are some tips for getting good sleep from the American Academy of Sleep Medicine:

  • Follow a consistent bedtime routine.
  • Establish a relaxing setting at bedtime.
  • Get a full night's sleep every night.
  • Avoid caffeine or any other stimulants before bedtime.
  • Be worry-free at bedtime.
  • Don't go to bed hungry or too full.
  • Avoid rigorous exercise within six hours of your bedtime.
  • Make your bedroom quiet, dark and a little cool.
  • Get up at the same time every morning.
CONCLUSION

Clearly, sleep is not only for the brain, but also for the rest of the body. Recent evidence suggests that sleep loss, a highly prevalent – and often strongly encouraged – condition in modern society could be a risk factor for major chronic diseases, including obesity and diabetes. Taking steps to ensure a good night’s sleep each night is key to maintaining proper body function and avoiding unhealthy weight gain. Scheduling your nightly time in bed will help to avoid any disruptions in sleep. And adding cliniCAL’s PM Formula to your daily regimen will ensure that you will sleep better for better recovery and improvement in weight management, plus awaken every day feeling rejuvenated, refreshed and ready to take on the world!