How are your sleep, your weight and your hormones related?

The hypothalamus is a region in the center of our brain that can be considered the master controller. It is responsible for many functions in our body, mainly to maintain homeostasis - or the delicate balance of our internal system despite both internal and external fluctuations. The hypothalamus takes in information both from our body as well as our external environment and directs our physiologic processes, through various mechanisms, to keep our “parameters” within certain safe limits. These parameters include our heart rate, blood pressure, temperature, hydration (via thirst), energy levels (via hormones, metabolism and hunger), emotions and behavior, and the all important aspects of this discussion - our weight set point, our hormone regulation and our 24-hour circadian rhythm. 

When the hypothalamus receives signals that one of these parameters is reaching levels outside of the safe zones, or when it receives input from our environment that we could be under an external threat, it automatically starts directing the processes in our body to make adjustments and preparations to counteract the imbalance. It triggers thirst when our fluid balance is getting low. It diverts energy from metabolism and reproduction to our muscles and heart in preparation for a fight or flight response. It is the master controller. 

So as we can see, this is where our weight, hormones and sleep intersect. But how are they all related to one another?

Let’s start with hormones. 

Your endocrine system, or hormone system, is made up of a bunch of amazing, complicated, beautiful, primary and back-up negative feedback loops. The most straightforward way to look at this is that the hypothalamus takes in signals from the body, such as certain hormones are too low in our bloodstream or the effects of specific hormones are not occurring at a high enough rate. The hypothalamus then sends signals to the pituitary gland (located a little lower in the brain) which then releases hormones that tell the specific endocrine organs to increase production of their particular hormone; the thyroid gland releases thyroid hormone, the adrenal gland releases cortisol (among others), the gonads release sex hormones (such as testosterone and estrogen). Once the hypothalamus detects adequate levels of the hormones or their specific effects, it then decreases pituitary signaling and thus the specific hormone production. 

It’s important to note here that this is a negative feedback loop. Our human bodies were not designed to be constantly releasing hormones non-stop. Instead, our bodies were set up to have pulses of hormones released both in response to certain stimuli (think stress causing the release of cortisol) and at certain times. Most importantly, our hormones follow a cyclical, 24-hour daily rhythm. This means that certain hormones, such as thyroid and growth hormone, are elevated at night to help with growth, repair and clean-up processes in the body, and other hormones, such as cortisol, testosterone and estrogen, are on during the morning to help us wake up and experience a burst of energy to start our day. 

Additionally, there is lots of cross-over between the hormones’ functions and their feedback loops. For instance, thyroid and testosterone increase metabolism, multiple hormones contribute to energy levels and insulin sensitivity, cortisol and estrogen can improve mental awareness. Everything is related and there is back-up, upon back-up, upon back-up. 

Next let’s talk about weight. 

Our weight-set point, or our body’s preferred weight, is set by the hypothalamus and greatly influenced by the amount of insulin that the body sees on a regular basis. Insulin is also a hormone, but it is released by the pancreas in response to carbohydrates consumed in our diet (versus being under direct control from the hypothalamus). However, as we saw above, almost every hormone that is under direct control from the hypothalamus plays a role in our body’s response to insulin. Insulin, testosterone, growth hormone and estrogen all help increase our body’s sensitivity to insulin, meaning that our body is more responsive to it. Cortisol, on the other hand, decreases insulin sensitivity which results in insulin resistance. 

Insulin resistance means that our tissues (brain, muscles, liver, etc) do not respond to insulin, resulting in higher levels of blood sugar which drives up the pancreas’ production of insulin, which results in higher insulin levels. This sets us up for a very negative cycle where we can’t turn off our insulin production. And this excess insulin results in our weight set-point increasing, and increasing and increasing. This means that the hypothalamus is always trying to keep our weight higher and higher by stimulating our appetite more and more. How are we ever expected to lose weight when we are both hungry all of the time and not using the food that we are consuming in an adequate fashion? When our hormones are imbalanced, our weight suffers. 

And finally, sleep. 

The sleep hormone, melatonin, is also partially controlled by the hypothalamus. Instead of being directed via the pituitary, melatonin’s release is done in the pineal gland. The pineal gland largely releases melatonin in response to light and temperature, more specifically low, warm light and cooler temperatures, but it can be overridden by the hypothalamus when conditions necessitate not sleeping, such as when our safety is threatened. 

So how are these all related?

Your cyclical release of hormones are intimately related to the 24 hour circadian rhythm. If this rhythm is off, so too will your hormones be. The ability for sleep is not only a marker of your hormonal health, but a significant component of it and vice versa (your hormones are not only a marker of your sleep health, but a significant component of it). As discussed above, if your hormones are off chronically (long-term), the easier it will be to develop insulin resistance and excessive weight gain. 

So what can you do?

Although these processes are intimately connected, you don’t need to correct everything to get big benefits. Just starting with improving your sleep can be the first step to getting your hormones and weight on track. 

Start with making sleep a priority, not a luxury. It is non-negotiable to set aside regular time on a daily basis to get adequate sleep. Just refocusing your mindset about sleep can go a long way. 

Next, get up at the same time EVERY SINGLE DAY, even on weekends. This not only improves your sleep, but it’s one of the best things you can do to keep your hormones on track. Allowing your body to follow a consistent routine sets these cyclical processes up for success. 

Lastly, manage stress, worry and anxiety, especially in the evening. Easier said than done, right? But it is so important to your sleep and hormonal health. Your hypothalamus has not evolved to the level of understanding the difference between real and perceived threats. It will treat a bear trying to attack you similarly to you imagining an argument with your boss in future. You must learn what works for you in releasing those negative thoughts and emotions instead of holding on to them, because they will just pop up when you are trying to fall asleep at night. Try out meditation, journaling, exercise, breathing techniques, counseling or any other relaxation practice that speaks to you. Just keep working at it until you find what sticks. 

Check out this video on sleep, your hormones and your weight:

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