Why is sleep the missing link for weight loss? I've got one word for you: hormones.
Sleep deprivation causes hormone imbalance (Leptin, Ghrelin, cortisol, you name it). These out-of-balance hormones wreak havoc with appetite and metabolism. The result? When you are low on sleep, you're more inclined consume extra calories, and you're less able to burn off the calories and fat you consume.
Here's a quick rundown of how sleep loss and hormone imbalance can mean bad news for your weight-loss goals:
When you sleep less, you take in more calories. This can happen for several reasons related to your hormones.
- Changes in your glucose metabolism brought on by sleep deprivation will cause your body to hoard the calories you consume, storing them as fat rather than burning them for energy.
- Low sleep causes your body to produce more of the stress-hormone cortisol, which in turn spurs your appetite.
- And let's not overlook the basic reality that when you sleep less, you simply have more time to eat! Late-night snacking can seriously undermine an otherwise healthy diet-and-exercise regimen.
When you sleep less, you burn fewer calories and burn less fat. Research indicates that a body deprived of sleep burns calories less effectively than a well-rested one. We know that the body burns more calories in REM sleep than at any other stage of sleep. We experience longer periods of REM sleep as we move deeper into our sleep cycle over the course of a night. An abbreviated night of sleep cheats your body of the REM sleep that is prime calorie-burning time. Research also has shown that people who sleep less and still manage to lose weight will lose less actual fat.
- One study showed a group of dieters lost the same amount of weight regardless of the amount of sleep they received. However, the group of dieters who slept more lost significantly more fat than their lower-sleep counterparts.
Like other aspects of sleep loss, the sleep-hormone-weight gain dynamic is more complicated for women because of monthly hormonal shifts associated with menstruation. According to a poll by the National Sleep Foundation, more than 70 percent of menstruating women experience disrupted sleep. The primary hormones involved here are estrogen and progesterone, both of which have critical functions related to sleep and weight loss.
- Estrogen increases REM sleep, which helps burn calories but also can lead to feelings of over-stimulation that make falling asleep more difficult.
- Progesterone can bring about drowsiness, but it also makes you feel sluggish and fatigued. Progesterone also increases appetite. The rise and fall of estrogen and progesterone affect sleep, appetite, and energy level in different ways during each phase of a woman's monthly cycle.
Here are some simple strategies that can help lessen the effects of menstrual hormone shifts on your sleep and on the quality of your waking life:
- Re-fill your glass: Upping your fluid intake will help your body flush out extra sodium, helping to diminish bloating and discomfort.
- Reach for the calcium: One study found that a 1200-milligram daily dose of calcium reduced PMS symptoms by 50 percent.
- Add magnesium: There is evidence that magnesium increases the body's production of the calming-hormone serotonin. Used in combination with calcium, magnesium is a great muscle relaxant, helping to soothe cramps and other physical discomforts.
Interested in learning more about exactly how hormones affect your weight, and how you can combat them with sleep? The Sleep Doctor's Diet Plan can help guide you through these questions and more.
Michael J. Breus, PhD
Michael J. Breus is the author of The Sleep Doctor's Diet Plan: Lose Weight Through Better Sleep. Follow Dr. Breus on Twitter and Facebook.