Sleep plays an important role in weight management. People who sleep enough have lower body mass indexes (BMI) than people who don’t. Recent research data suggests that sleep deprivation can cause weight gain. Women who got only 4 hours of sleep at night ate 329 additional calories the next day than they did after they slept nine hours. (Men ate 263 calories more.) In another study, 11 volunteers spent 14 days at a sleep center on two occasions. During one period, they slept 5.5 hours a night, and during the other, they slept 8.5 hours. When the subjects were sleep-deprived, they increased their nighttime snacking and were more likely to choose high-carbohydrate snacks.
The biggest revelation about the connection between sleep and weight loss, and the biggest challenge for you if you’re not getting at least seven solid hours of sleep each night, is that sleeping too little impacts your hormone levels in ways that can undermine the efforts of even the most determined dieter. There are several hormones that link sleep with weight loss. Leptin and ghrelin are two hormones that play an important role in stimulating and suppressing your appetite. Ghrelin’s job is to boost your appetite, increase fat production, and make your body grow, which are undesirable effects once you’ve passed your teenage years. It’s easy to figure out why this hormone is the last thing a dieter needs to have circulating in excess. On the other hand, leptin is responsible for suppressing hunger. Leptin is the hormone that says, “I’m full; put the fork down.” Lack of sleep lowers the levels of leptin in your blood and heightens the levels of ghrelin, which results in an increase of appetite. The reverse is also true: getting enough sleep decreases hunger and will therefore help you lose weight. So after even one night of too little sleep, leptin and ghrelin become dietary gremlins bent on diet-wrecking mischief. The lower leptin levels mean that you still feel hungry after you eat. And ghrelin, for its part, magnifies the problem by stimulating your appetite, setting the stage for a day of high simple carbohydrate, high-calorie feasting after a restless night. Another important hormone affected by sleep is growth hormone. During sleep, your pituitary gland secretes more growth hormone than during your waking hours. Growth hormones stimulate cell regeneration, reproduction and growth. These hormones are also known to aid you in building muscles. This is why higher levels of growth hormones results in a heightened metabolism. With a higher metabolism, you burn energy faster, which will lead to easier weight loss. Finally, cortisol is another important hormone affected by sleep. Getting eight hours of sleep at night helps you lower the cortisol levels in your blood, while lack of sleep raises your cortisol levels. High levels of cortisol lead to a lower metabolism and cause you to crave simple carbs. High cortisol levels lead to elevated blood sugar levels, increased insulin levels, and finally obesity. (Stress also leads to increased cortisol levels.) If you are trying to lose weight, you want to make sure that you have low cortisol levels in your blood. Low cortisol levels lead to lower insulin levels, which help you to lose weight. Getting enough sleep helps you do just that.
Overall, sleep is a crucial factor in losing weight. Sleep suppresses your appetite and raises your metabolism, while allowing your body to rest and recover. So aside from eating a nutritious, high fiber diet and participating in regular aerobic exercise, you should also make sure that you get your full seven to eight hours of sleep every night to help you optimize your hormone levels and promote weight loss. Do not skimp. The next post will discuss several ways to help you sleep.
Most people do not think about their sleep habits when evaluating their health. Adequate sleep is critical when trying to lose weight, maintaining your weight and improving your overall health. Recent evidence suggests that your sleeping habits influence both your ability to lose weight and your tendency to eat more. People trying to lose weight were more likely to lose ten pounds when they slept between six and eight hours a night. People ate an average of nearly 300 calories more when they were sleep-deprived compared to when they were well rested. The calories overwhelmingly came from junk foods like ice cream and fast food. Other research found that among adults younger than 40, those who typically slept for five hours or less each night had a greater accumulation of belly fat. Another study found dieters who slept for 8.5 hours lost 55 percent more body fat than dieters who only got 5.5 hours of sleep. These studies only scratch the surface of the research linking your sleeping habits with your body weight. What is the connection? It is likely the effect of altered metabolism, because when you’re sleep deprived, leptin (the hormone that signals you are full) falls, while ghrelin (the hormone which signals you are hungry) rises. In one study, researchers found that people who slept only four hours a night for two nights experienced an 18 percent reduction in leptin and a 28 percent increase in ghrelin This combination leads to an increase in appetite. As mentioned above, people ate 300 extra calories when they were sleep-deprived. Furthermore, sleep-deprived people tend to eat more sweet and starchy foods, as opposed to vegetables and proteins. Sleep deprived people tend to crave sugary treats such as ice cream and candy. These sugar cravings may stem from the fact that your brain is fueled by glucose (sugar); therefore, when lack of sleep occurs, your brain starts searching for carbohydrates to keep going. Increased intake of simple carbs (highly processed foods) leads to increased insulin levels and weight gain. If you’re chronically sleep deprived, and consistently give in to these sugar cravings, you will virtually guarantee weight gain. Other consequences of too little sleep include: high blood sugar levels/insulin resistance, an increased risk of diabetes, hypertension, depression, accelerated aging, and an increased risk of cancer. How do you know if you are getting enough sleep? If you feel well-rested and are able to wake up in the morning with no problem, you’re probably doing just fine in the sleep department. But if you’re fatigued, nodding off or yawning throughout the day, and just want to go back to bed when your alarm clock goes off in the morning, your sleep schedule may need some adjusting. Adults tend to need between six and eight hours of sleep every night. However, there are plenty of exceptions. Some people feel rested on as little as five hours a night, while others need as much as nine or ten in order to feel their best. The amount of sleep you need can also drastically change depending on circumstances. For example, most people need more sleep when feeling ill, or during emotionally stressful times. Pregnant women also typically need more sleep than usual during the first trimester. Listen to your body and respond accordingly. And don’t think you’re going to meet all of your sleep needs by sleeping in for one morning on the weekend. Chronic lack of sleep has a cumulative effect when it comes to disrupting your health. You cannot skimp on sleep during the weekdays, thinking you’ll “catch up” over the weekend. What’s needed is consistency, and when it comes to sleep, routine is the word. Good sleep habits are critical to your long-term health. Make sure you get a good nights sleep to improve your weight and overall health.