BLOG SLEEP, HEALTH
April 12, 2013
Sleep well... or be hungry!
Sleep is a necessary part of life. You get tired for a reason: keeping your body alive and functioning all day takes work, and your body needs time to recover. Sleeping is when much of this recovery happens. As you progress though the day a substance called adenosine builds up in your brain. This is a metabolic end product from your cells burning and utilizing energy. As adenosine builds up you start to feel tired. Eventually, you become tired enough where you feel you must go to sleep. Throughout the night your brain dips and rises through different levels of consciousness, each level allowing the brain and body to recover. During sleep your body heals and your brain recovers. A lack of sleep can be detrimental to your health.
For this post, let’s focus on one result of a lack of sleep: decreased metabolic activity. Yup. You burn fewer calories at rest after a night of crappy sleep compared to a night of wonderful sleep. Do you remember that hormone called ghrelin? It is released from your stomach cells at levels inversely proportional to stomach size and triggers the feeling of hunger. After a night of poor sleep, you will have elevated levels of ghrelin… meaning you will be hungrier. Remember that hormone called leptin? You know, the one that is released by your fat cells and makes you feel full? Leptin levels decrease when a person is unrested. This means that on a day when you slept poorly the night before, you will be hungrier.
Leptin is not only a long term food regulator. Another of its many roles is to stimulate the release of thyroid stimulating hormone from the brain. The thyroid contributes to your basal metabolic rate (amongst other things) and is very important in managing your metabolism. When you have lower leptin levels, you are not getting the same level of stimulation for thyroid hormone release, causing a decrease in your resting metabolic rate.
What about coffee? Caffeine acts to stimulate your central nervous system by blocking the adenosine receptors in your brain. Even when your receptors are blocked, adenosine continues to build. Once your body clears out the caffeine, you are no shorter in stock of adenosine. Caffeine has a half-life of about 5 hours (in a typical person), and when it wears off, you will be back to feeling as tired as you would have been based on your recent quality of sleep.
How much sleep should you be getting? As much as you need! Everyone is different, but generally speaking people need between 7-9 hours. Get your sleep! If you don’t, you will be hungrier, slower, and burning less calories. Is that really how you want to live your day?
Stay strong, Team!