By Dr. Mercola
A new study of 1,800 pairs of twins found that even if you're genetically predisposed to being overweight, there is one easy thing you can do to put yourself in control of how much weight you gain.
As reported by CNN, researchers found that genes accounted for 70 percent of the differences in body mass index (BMI) in those who slept less than seven hours per night. Environmental factors, such as diet and exercise, accounted for just four percent of the differences. But in twins who slept nine or more hours per night, environmental factors shot up to 51 percent, and genetic influences dipped to 32 percent. So, sleep deprivation appears to have a significant influence over your genetic expression.
According to CNN Health1:
"Getting adequate sleep, in other words, appears to dampen genetic risk and allow the influence of diet, exercise, and other controllable lifestyle factors to "surface," the researchers say."
Sleeping Well Matters if You're Struggling with Your Weight
Previous research has already shown that people who sleep less than seven hours a night tend to have a higher body mass index (BMI) than people who get more sleep. The biological mechanisms linking sleep deprivation and weight gain are numerous.
Alterations to your metabolism account for some of this effect, because when you're sleep deprived, leptin (the hormone that signals satiety) falls, while ghrelin (which signals hunger) rises. In one 2010 study2, researchers found that people who slept only four hours for two consecutive nights experienced:
- 18 percent reduction in leptin
- 28 percent increase in ghrelin
This combination leads to an increase in appetite. Additionally, sleep deprivation tends to lead to food cravings, particularly for sweet and starchy foods. Researchers have suggested that these sugar cravings stem from the fact that your brain is fueled by glucose (blood sugar); therefore, when lack of sleep occurs, your brain starts searching for carbohydrates to keep going. If you're chronically sleep deprived, consistently giving in to these sugar cravings will virtually guarantee that you'll gain weight.
Sleeping less than six hours per night can also radically decrease the sensitivity of your insulin receptors, which will raise your insulin levels. This too is a surefire way to gain weight as the insulin will seriously impair your body's ability to burn and digest fat. It also increases your risk of diabetes. In short, sleep deprivation puts your body in a pre-diabetic state, which can lead to increased weight and decreased health.
Sleep Deprivation, Stress, and Weight Gain
Biological stress is another mechanism that can help explain the link between poor sleeping habits and increased risk of weight gain. According to the featured article on CNN Health3:
"Sleep deprivation puts stress on your body, and that stress could help explain the relationship between sleep and gene expression seen in the study, says Carl Boethel, M.D., director of the Sleep Institute at Scott & White Healthcare, in Temple, Texas. "When you are constantly depriving yourself of sleep, you are keeping yourself in a state of stress, and the genes that encode for that stressful environment start saying, 'I need to hold on to calories,'" Boethel says".
When your body is under stress, it releases hormones that increase your heart rate and blood pressure. Your muscles get tense, your digestive processes stop, and certain brain centers are triggered, which alter your brain chemistry. For example, it tends to raise your levels of corticosterone, the stress hormone associated with road rage. Left unchecked, this stress response can eventually lead to a variety of health problems including:
- Increased anxiety
- High blood pressure
Unfortunately, precious few are willing to take a much-needed look at their sleeping habits and make the required readjustments to their schedules and habits. I strongly urge you not to be part of the majority in this regard...
How Much Sleep Do You Need?
Chronic lack of sleep has a cumulative effect, so you cannot skimp on sleep on weekdays and then try to "catch up" over the weekend. In order to benefit your health, you need to be consistent in your sleeping habits.
As a general rule, adults need between six and eight hours of sleep every night. However, there are plenty of exceptions. Also, as the featured study on twins suggests, you may need upwards of nine hours a night in order for it to outweigh certain genetic predispositions, by allowing your body to reap maximum benefits from a healthy diet and exercise regimen. The amount of sleep you need can also drastically change depending on your circumstances, such as illness or going through an emotionally stressful time.
Pregnant women also typically need more sleep than usual during the first trimester. My advice is to pay close heed to your body, mind and emotional state. For example, if you consistently feel tired upon waking, you probably need to sleep longer. Frequent yawning throughout the day is another dead giveaway that you need more shut-eye.
Optimizing Your Sleep Sanctuary
There are many factors that can influence your sleep, but one that many fail to consider is the use of light-emitting technology, such as your TV, iPad, and computer, before going to bed. These emit the type of light that will suppress melatonin production, which in turn will hamper your ability to fall asleep. Ideally, you'll want to turn all such light-emitting gadgets off at least an hour prior to bed time. Next, making some adjustments to your sleeping area can also go a long way to ensure uninterrupted, restful sleep:
- Cover your windows with blackout shades or drapes to ensure complete darkness. Even the tiniest bit of light in the room can disrupt your pineal gland's production of melatonin and serotonin, thereby disrupting your sleep cycle.
So close your bedroom door, get rid of night-lights, and refrain from turning on any light during the night, even when getting up to go to the bathroom. If you have to use a light, install so-called "low blue" light bulbs in your bedroom and bathroom. These emit an amber light that will not suppress melatonin production.
- Keep the temperature in your bedroom at or below 70 degrees F (21 degrees Celcius). Many people keep their homes and particularly their upstairs bedrooms too warm. Studies show that the optimal room temperature for sleep is quite cool, between 60 to 68 degrees F (15.5 to 20 C). Keeping your room cooler or hotter can lead to restless sleep.
- Check your bedroom for electro-magnetic fields(EMFs). These can also disrupt your pineal gland's production of melatonin and serotonin, and may have other negative effects as well. To do this, you need a gauss meter. You can find various models online, starting around $50 to $200. Some experts even recommend pulling your circuit breaker before bed to kill all power in your house.
- Move alarm clocks and other electrical devices away from your head. If these devices must be used, keep them as far away from your bed as possible, preferably at least three feet.
If you're feeling anxious or restless, try using the Emotional Freedom Technique (EFT), which can help you address any emotional issues that might keep you tossing and turning at night. For many more recommendations and guidelines that can help you improve your sleep, please see my article 33 Secrets to a Good Night's Sleep.