What if you were told that there’s an effective weight loss method that costs nothing and doesn’t require you to change your diet or exercise?
What if you were told that you could lose weight while you sleep? And that sleep itself -- not some magic fitness contraption -- is one of the best-kept weight loss secrets? Saying that people who sleep more end up eating less (and being less hungry) might be oversimplifying a little too much, but in essence, that’s what multiple studies have found.
Two studies have shown a link between sleep deprivation and a propensity to gain weight. In a study published in 2012, “Short Sleep Duration, Glucose Dysregulation and Hormonal Regulation of Appetite in Men and Women,” participants consumed over 300 more calories a day after four hours of sleep than after nine hours of sleep. “That could translate into 31 pounds a year,” says Kelly Plowe, R.D.
A 2006 study, “Association Between Reduced Sleep and Weight Gain in Women,” followed more than 68,000 women for 16 years. It found that those who slept five hours or less a night were more likely to gain more weight than those who got seven hours of sleep a night.
Why Do People Who Don’t Get Enough Sleep Gain Weight?
Sleep deprivation increases a hormone called ghrelin, which triggers appetite, and decreases one called leptin, which signals that you are full. So people who sleep less tend to eat more. In a 2004 Stanford University study, "Sleep Duration Affects Appetite-Regulating Hormones," participants who slept less than eight hours a night had higher levels of ghrelin, lower levels of leptin and more body fat. Those who slept the least were found to weigh the most.
People who experience sleep deprivation have also been shown to be more likely to consume high-carb, high-calorie foods. “Say you’re sitting in a room with a cookie,” says Dr. Sanjay Patel, a lecturer in medicine at Harvard Medical School and an associate physician in sleep medicine at Brigham and Women’s Hospital in Boston. “If you’re well-rested, you might say, ‘I know it tastes good, but I’ll regret it longer term.’” When you’re tired, on the other hand, you’re more likely to simply give in to impulse.
Patel added that when you are deprived of sleep you might be less inclined to exercise. This is because fatigue could influence not just decisions like whether you eat a cookie, but also whether to go to the gym or whether to take the stairs or the elevator.
Rest Up, Slim Down
While the current research focuses on sleep deprivation leading to weight gain rather than an increase in sleep leading to weight loss, there’s some evidence to suggest it works both ways, says Patel.
Michael Breus, Ph.D., author of The Sleep Doctor's Diet Plan, and a psychologist board-certified in sleep disorders and a practicing sleep specialist for the past 15 years, initially noticed a connection between sleep gain and weight loss in his practice. “I had sleep apnea patients who would get treated and start getting a good night’s sleep, and the pounds would drop off. They’d come see me and say, ‘I haven’t changed a thing and I’ve lost 15 pounds.'”
Granted, most people may not be as sleep-deprived as Breus’ patients, but the average adult gets only six hours and 51 minutes of sleep on weeknights, according to the National Sleep Foundation, which says most people need seven to nine hours of sleep a night. The quality of sleep also is important. Poor sleep habits can sabotage what might otherwise be a good night’s rest.
How to Get Better Sleep
STEP 1 - FIGURE OUT HOW MUCH SLEEP YOU REALLY NEED.
You want to get enough sleep to feel well-rested. “That means you won’t be dragging at the end of the day," said Patel. "You don’t feel like napping, and you don’t need a coffee pick-me-up in the afternoon.”
But how do you determine what enough sleep means for you?
Most adults have a wake-up time determined by outside factors, such as when they have to get to work or when their kids get up. Count back seven and a half hours from whatever that time is for you and that’s the bedtime to start with, advises Breus. Why seven and a half hours? Sleep cycles are 90 minutes long, and the average person has five of them per night. However, there can be significant differences on an individual level, with some people needing more time and some needing less. Breus explains that if you find you’re consistently waking up an hour earlier than your target wake-up time, you only need six and a half hours. But, if after doing this experiment for a week you need an alarm to wake up, it means you need more sleep.
STEP 2 - KEEP A CONSISTENT BEDTIME.
It’s not only about how many hours you sleep, but also about consistency. In other words, you want to avoid going to bed at 3 a.m. some nights and other nights at 10 p.m., even if you get the same amount of sleep. Patel warns that if you get four hours some days and ten hours on weekends, you’re more susceptible to gaining weight.
“Your bedtime shouldn’t vary by more than about a half-hour,” said Breus, “but the real anchor is your wake-up time.” When you wake up at the same time every day, it keeps your internal clock functioning more efficiently. So even if you go to bed a little later than usual, don’t sleep in to make up for it. Just go to bed a little earlier the next night. Breus also suggests spending 15 minutes in the sun every morning to help reset your internal clock. That helps your body get conditioned to wake up and go to sleep at the same times every day.
And don’t rely on the snooze button to give you the feeling of sleeping in by setting your alarm early. “The snooze button is the worst invention ever,” said Breus, adding that seven to nine minutes is not enough time for anything but poor-quality sleep.
STEP 3 - CREATE AN ENVIRONMENT THAT ENCOURAGES SLEEP SUCCESS.
During deep sleep, the body increases levels of growth hormone, which breaks down fat and has been associated with a lower risk of obesity. To increase your percentage of deep, slow-wave sleep, you’ll need to set up the right conditions for a good night’s rest.
First, suggests Patel, maximize good-quality, slow-wave sleep by going to bed in a quiet, comfortable room. Keep it dark and cool.
Breus also recommends spending at least 20 minutes relaxing right before you go to sleep, reading in bed or meditating, for example. But avoid watching TV or using a laptop, tablet or cell phone in bed, since exposure to the bright light from electronics has been shown to reduce melatonin levels, which can disturb sleep.
STEP 4 - CUT BACK ON CAFFEINE, ESPECIALLY LATE IN THE DAY.
Although caffeine may slightly suppress your appetite, it’s also a stimulant that can prevent you from falling asleep. According to Breus, the easiest way to improve your sleep is to reduce your caffeine intake.
“I don’t think there’s a problem with having two, three, four cups in the morning,” says Patel, “but more than that suggests you’re not getting enough sleep, masking fatigue.” Patel recommends no caffeine up to six hours before bedtime. Breus takes it further. He suggests no caffeine after 2 p.m. and limiting your daily intake to 250 to 300 mg (about the amount in a couple of cups of coffee).
STEP 5 - DECREASE DRINKING, ESPECIALLY RIGHT BEFORE BED.
Sure, drinking puts you to sleep, says Patel, but as the alcohol metabolizes out of your system, you’ll wake up more frequently, especially in the second half of the night.
“Alcohol is the No. 1 sleep aid in the world -- but it also interferes with deep, restorative sleep,” said Breus. That’s why he recommends no more than two alcoholic beverages a day and none within three hours of bedtime.
STEP 6 - GET AT LEAST A LITTLE EXERCISE EVERY DAY.
OK, so you don’t have to change your exercise habits, but even mild activity ensures better quality sleep, according to a survey by the National Sleep Foundation. “Doing any type of exercise, even if it’s just going for a walk, will absolutely help with sleep quality,” said Breus. And it may help you lose even more weight.
- ScienceDaily: Sleep Duration Affects Hunger Differently in Men and Women
- Time: Losing Sleep Leads to Gains in Weight
- American Journal of Epidemiology: Association between Reduced Sleep and Weight Gain in Women
- Stanford School of Medicine: Stanford Study Links Obesity to Hormonal Changes from Lack of Sleep
- ScienceDirect: Light Level and Duration of Exposure Determine the Impact of Self-Luminous Tablets on Melatonin Suppression
- The University of Chicago Medicine: Sleep Loss Boosts Appetite, May Encourage Weight Gain
- National Sleep Foundation: National Sleep Foundation Poll Finds Exercise Key to Good Sleep
- National Sleep Foundation: How Much Sleep Do We Really Need?
- Mayo Clinic: Caffeine Content for Coffee, Tea, Soda and More