Why Our Body Needs Sleep
Longfellow once said, “Be thy sleep silent as night is, and deep.” But is actually the case? Most of us can only dream of the idea of our head hitting the pillow and not waking until the morning. We know that the benefits of sleep extend beyond the simple notion of the importance of getting enough shut eye–all of the systems in our body need sleep. The immune system needs is so that we can fight off disease and infections. The cardiovascular system needs sleep to help the heart vessels heal and rebuild and help maintain blood pressure, sugar levels, and inflammation control. We also know that too little sleep may increase the risk of cardiovascular disease. Sleep deprivation affects the prefrontal cortex, which handles reasoning, and the amygdala, which deals with emotion. A lack of sleep may also make it harder for a person to form new memories, which can affect learning. And a lack of sleep can also impact fertility as poor sleep may affect the production of necessary hormones.
While it’s always important to understand the importance of sleep with respect to all the systems, the big reason sleep is highlighted in my practice is because I work primarily with folks who want to lose weight and guess what also is impacted by poor sleep? Yup, your weight! To understand the “why” in all of this, I want to back up to talk a little bit about the “how”.
“Magic Hours”
I tell my clients that the hours between 10pm-2am are the “magic hours” of the night when our body really goes to work to do it’s repairing, restoring and waste clean-up. Other benefits include free radical removal and hormone secretion, including the production of growth hormones and testosterone. It also causes the body to release additional stress hormones, such as norepinephrine and cortisol. The other hormones that get secreted during this time are the satiety hormone leptin and the hunger hormone ghrelin. In other words, sleep can affect the hormones that control feelings of hunger and fullness. Scientists have found that as people lose sleep, they experience physiological changes that can nudge them to seek out junk food.
One study found that when individuals were restricted to four hours of nightly sleep for five nights in a row, they had greater activation in reward centers of the brain in response to pepperoni pizza, doughnuts and candy compared to healthy foods such as carrots, yogurt, oatmeal and fruit. After five nights of normal sleep, however, this pattern of stronger brain responses to the junk food disappeared. Cravings for added sugar seem to decrease with even as little as an hour more sleep/night in sleep deprived individuals. In clinical trials, healthy adults who are allowed to sleep only four or five hours a night end up consuming more calories and snacking more frequently throughout the day. They experience significantly more hunger and their preference for sweet food increases.
Why sweets?
Sugar = energy. Think about it, if sugar is our body’s quickest source of energy, it makes sense that when we are tired, we seek it out. Think of your afternoon sweet tooth. If you find yourself craving sugar constantly, one of the first places to look is to your energy levels and how that correlates with how much (or little) sleep you have been getting. Remember though that not all sugar is equal. It can feel good in the tired and sleepy moment to reach for a piece (or five) of chocolate, but that intense sugar and energy spike that follows is going to plummet and lead to a crash, making you even more tired. Sugars from candy, soda, etc. aren’t going to have the same properties of the sugars from fruits, veggies and complex carbs. The latter will provide you with blood-sugar stabilizing fiber, as well as vitamins and minerals.
What do I do?
There’s a whole lot you can and should be doing nutritionally to help with your sleep. Number one—focus on meal timing. Do not eat 3-4 hours before bedtime. Late night eating is harmful for the metabolism and affects sleep (remember…your body loves a schedule!) A lot of my practice is based around honoring your circadian rhythm and late-night eating/snacking disrupts the digestive clock and reignites the metabolism interfering with the body’s ability to both fall and stay asleep. Think of this–to fall asleep, our core temp needs to decrease by one degree Fahrenheit but eating makes our core temp go up (blood rushes to gut to help with digesting and absorbing nutrients) thereby making it harder to fall asleep.
Another reason I stress honoring your circadian rhythm is because it’s responsible for the part of your brain that controls many important functions like the production of digestive enzymes. And if these functions are interrupted, it affects your ability to properly break down food, and leads to you feeling hungry, even if you aren’t which can lead to weight gain and other health issues. Aligning your eating and sleeping habits to match up with your body’s natural tendencies is one way to honor the specific dietary and lifestyle needs your body has.
The other thing I focus on is the actual food you are eating. Less protein, less produce and fiber, and a higher intake of added sugar and processed foods all shown to have poorer sleep quality. Adding in fiber, high quality protein sources as well as healthy fats are a great way to not only improve your overall health but also help you get better quality shut-eye.
