We know that our bodies are way more complex than the old “calories in, calories out” adage would suggest.  There are so many other factors that tie into our metabolism including body composition, hormones, stress, sleep, and hydration.  And one of the major things people don’t realize impacts your metabolism is meal timing.  In fact, eating the exact same meal at different times of the day can have a completely different impact on your metabolism.  This is, in part, related to the relationship between our sleep cycles and our hormones.  So, it’s important to understand this relationship to learn how to maximize mealtimes to help you manage your weight.  And it may have you rethinking that late-night snack!


Our Circadian Rhythm

There’s no denying the impact that electricity has had on modern life.  Before it, our lives were much more tied to the cycles of the sun and our sleep schedules were more directly tied to darkness.  Now, all of the conveniences of modern technology mean we don’t have to worry about light or darkness:  we can make as much light as we want at any time of day!  This can be incredibly convenient for a host of reasons, but the problem is that it disconnects us from our natural circadian rhythm which is directly tied to the sun.

Our bodies have a 24-hour clock that dictates our hormone patterns, our biological patterns, and even our behavioral patterns.  This clock relates to everything that happens in our body, including sleep hunger, and even our metabolism.  So, our bodies were designed to eat during daylight hours and sleep after dusk---a pattern that most of us have moved very far away from!  The problem is that our biology hasn’t made this same change; it still functions on the same 24-hour clock, or circadian rhythm, that it did in our caveman days.  So, if we want to eat more optimally for our bodies, we might need to get more in touch with this internal clock.


The Role of Melatonin

Melatonin is our body’s sleep hormone and it’s directly tied to the sun.  As the sun starts to disappear in the evening and darkness looms, it triggers the release of melatonin, telling our body that it is time for sleep.  And then in the morning, when the sun rises, it signals melatonin to stop so that we can wake up and enjoy the day.  But this hormone (like all the others) doesn’t exist in a vacuum.  Its release and suppression is tied to other hormones in our body as well. 

Can you guess the other hormone that is most closely tied to melatonin?  You may never believe it, but it’s actually insulin!  You see, melatonin is telling us it’s dark and it’s time to sleep.  And if we are sleeping, we will almost certainly not be busy eating.  So, we won’t have much need for insulin.  So, melatonin cues our body to temporarily stop producing insulin. 

When we tie this idea with the idea of our circadian rhythm, that means that eating after it gets dark is a whole different experience in our bodies than eating during daylight hours.  During the day, our body is producing insulin to allow us to manage our blood sugar levels and process our carbohydrates effectively.  After dark, it’s a whole different story.  Without insulin production in the evenings, our blood sugar levels are higher, and we have no choice but to store more body fat.


Rethink Mealtimes

Considering this information might help you start to reconsider mealtimes: both what you eat and when you eat it.  For many of us, breakfast is a small meal, maybe a protein bar or a piece of fruit.  Dinner, on the other hand, is usually a big bowl of pasta or some form of meat and potatoes.  The reality is that our body would handle it much better if we were reversing that to meet with the old saying: “Eat breakfast like a king. Lunch like a prince. Dinner like a pauper.”

So, it’s unlikely that most of us are going to start changing our schedules to follow the sun and start going to bed as soon as the sun goes down.  But we can shift our mealtimes a bit to fit more with our body’s natural pattern.  The easiest way to do this is to make breakfast your biggest meal of the day and dinner your smallest.  Sounds strange right?  Well give it a try for a week or two and see what you think.  Your body will thank you!