Our sleep and our metabolism are intimately intertwined. Like all major processes of physical homeostasis, sleep plays an important role in the body’s ability to carry out its most vital metabolic functions.

If you’ve ever eaten a very heavy meal and tried to sleep directly after, you are likely anecdotally aware that this is true. The same goes for anyone who has suffered from sleep disorders and noticed a change in their weight and well-being. More and more, sleep and diet researchers are finding links between the quality of our sleep and the ability of the body to process food and nutrients efficiently.

But exactly how are the two processes linked? And what happens to our bodies when we start to lose sleep regularly? Is there a way to boost our metabolic systems by sleeping differently?

Read on for the answers to these questions and to learn more about the connections between sleep and metabolism.

What exactly is metabolism?

Metabolism can be defined as the biochemical processes that must occur to keep an organism alive. For the purposes of this article, we can limit the use of the term to the way the body breaks down calories to provide the body the energy it needs to function. This encapsulates the way we ingest, then digest food and drink.

Obviously, turning the things we eat and drink into usable fuel and building material for the body is a complex process with millions of moving parts. It requires cooperation from the brain, many parts of the body, and the environment a person finds themselves in. All of these factors determine how efficiently our metabolism processes the things we eat.

As we’ll find out, our own behavior when it comes to consumption and sleep also plays a big role.

Metabolism as we sleep

During the course of a normal night of sleep, our body is working subconsciously to maintain itself and our health. Changes in the way we metabolize the things we have ingested is an essential part of this process.

As we move through the sleep cycle, there are significant changes in energy consumption a healthy person should expect to experience in the course of the night. Typically, our metabolism slows about 15% during the night—though it is important to note that it will be higher or lower depending on the exact stage of the sleep cycle we happen to be on at any given time. Growth hormones and cortisol, two majorly important catalysts for proper metabolic functioning, appear to fluctuate systematically during the course of the night in order to maintain the ideal amount of energy consumption and storage that our bodies need.

Sleep disorders and metabolism

One illustrative way to continue examining the relationships between metabolism and sleep is to look at what happens to people’s metabolic processes when they suffer from sleep disorders.

A 2009 paper published in the academic journal Nature Reviews Endocrinology discusses over four decades of research into the subject of sleep disorders and metabolism. The authors write that there is overwhelming evidence that poor or short sleep, especially caused by disruptions associated with sleep disorders, leads to a “deleterious effect on glucose metabolism.”

Metabolizing glucose is essentially the way our body creates energy out of the food we eat. When that process is messed with, we see all sorts of nasty effects, from lethargy and depression all the way to diabetes and obesity.

The paper’s authors also claim that loss of sleep quality and quantity can also lead to problems with the proper functioning of the endocrine system, our bodies’ hormone creating and regulating mechanism. In particular, obstructive sleep apnea (OSA) was singled out as a sleep disorder that was deeply linked to endocrine disorders, as well as obesity and certain kinds of diabetes. As discussed before, hormones play a massive role in regulating the metabolic processes of the body, and any disruption to their functioning can and will lead to big problems with our overall health.

OSA is not alone in causing problems. Any sleep disorder that leads to a chronic drop off in either sleep quality or quantity is likely to affect our bodies’ metabolic efficiencies if it lasts long enough. This includes insomnia, restless legs syndrome (which has been linked in particular to problems metabolizing iron), and more.

Societal changes in sleep and metabolism

Considering the complex interconnectedness between our sleep health and our metabolic health, it is no wonder that scientists are taking a long hard look at co-existing trends towards worse sleep and increases in metabolic disorders across entire populations.

Authors of the 2009 paper in Nature Reviews Endocrinology claim that as sleep quality and quantity have decreased in the United States (for many reasons, as reported elsewhere) rates of diabetes and obesity have increased. The same goes for endocrine irregularities which seem to be exacerbated by sleep troubles, the authors claim.

As diabetes and obesity continue to be massive, consistently growing problems in the United States, the notion that changes in our national sleeping patterns could be partially to blame represent yet another potential avenue for solutions, along with changes to diet and exercise, that are worth exploring. Scientists recommend that doctors working with patients who suffer from these conditions ought to take time to discuss improving the sleeping patterns of their patients in order to combat these potentially deadly diseases.

Achieving a healthy metabolism with healthy sleep patterns

So what can you do to make sure your body’s metabolic processes are working in the way that they should be?

The short answer is one we often talk about: improve your sleep hygiene and routines.

For a more extensive guide to the best possible sleep, check out our longer article filled with tips on how to get the best sleep possible each night.

In the meantime, here are some important things to keep in mind about good sleep, especially when it comes to metabolism.

• Try to avoid heavy foods right before bed. At night, your body slows down metabolic processes. Forcing it to work overtime to digest things you eat right before bed can interfere with healthy cycles of metabolism.
• Alcohol, caffeine, nicotine, and other drugs ingested too close to bedtime will likely have a similar effect. We know these substances negatively impact our ability to sleep healthily, and we also know that many of them are directly linked to poorer metabolism functioning.
• Exercise is a great way to improve both sleep and metabolism. Working out causes your body to consume energy efficiently, and as we mention in our article about how exercise impacts sleep, working out and sleeping create a positive feedback loop that increases our ability to do either activity. For more on how to exercise for sleep, check out our article on the best types of exercise to promote healthy sleep!