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 Everyone knows that you cannot function for long when you are sleep deprived. Sleep can be regarded as the physiological equivalent to the reset button on your computer.

When a computer crashes, the surest way to solve the problem is to reboot.

It seems we modern-day humans have forgotten our intimate connection to sleep.

We do everything we can to circumvent it.

We stay up late into the night watching TV and surfing the Internet while feeding ourselves under artificial light.

In the morning we struggle to wake up using stimulants like coffee and sugar to “jump-start” our bodies and allow us to function once again.

Like most things in the modern world, sleep is treated as more of an annoyance than a critically essential process for optimal body function. It is not uncommon for people to brag they only require a few hours of sleep.

However, in order for them to stay functional, it requires large amounts of coffee along with sugar in the form of bagels, cookies, pastries, etc. It is not uncommon for these sleep-deprived individuals to end up with other poor habits that tend to potentiate one another.

What these people fail to understand is the effect their lack of sleep has on their individual metabolisms.

Weight issues do not come from a genetic defect that causes you to overeat, but rather are derived from a multitude of overlapping factors including sleep issues.

Lifestyle choices like sleep have the power to alter key hormones involved in metabolism.

The loss of fat from the human body is a complex biochemical process that goes far beyond simple one-dimensional models of calorie counting. Sleep is key to restoring your fat-burning software, and it is all related to ancient human metabolism.

Sleep and Hormones

You may be thinking, what can sleep possibly have to do with fat metabolism?

Well, you have heard of hormones right?

Hormones in the body are powerful chemical messengers that tell the body how to respond to the outside world. When most people think of hormones, they think of the sex steroids like estrogen, progesterone, and testosterone. These are definitely examples of hormones, but there are many different types of signaling molecules in the body that extend beyond the concerns of reproduction.

Being analogous to computer software for the body, hormones give the body instructions about how, when and why to respond to the outside world.

Some of the major hormones involved in fuel metabolism include insulin, leptin, cortisol, adrenaline, growth hormone, and thyroid hormone. The relative amounts of these hormones actually tell the body to burn fat or to store fat. Hormonal regulation of fat metabolism is “tuned into” our ancestral lifestyle and has enabled our species to survive to the present day.

If hormones are the body’s computer software, then the sense organs are its input devices. Your eyes, ears, nose, mouth, and sense of touch, temperature, and perception are analogous to the mouse, keyboard, CD drive, Internet connection, and input devices on your computer. Just like typing a command into a computer keyboard or loading a new program on your computer hard-drive, signals coming in from your body’s sense organs are the prime movers of hormonal metabolism.

Easily the most important signal received by the body is light. Here is a simplistic description of how light works: as the sun rises, those first beams of light hitting your closed eyelids send signals to the body’s nervous system. These signals produce a hormonal response characterized by a slow, steady climb of stress hormones, adrenaline, nor-adrenaline, and cortisol. These hormones then began to raise blood sugar, increase respiration, stimulate fuel metabolism, and elevate energy to wake you from sleep. From there, you are off.

The body receives environmental inputs and issues hormonal commands all day long. Food, sounds, light, exercise, stress, and even thoughts provide the stimulus for hormonal reactions that determine whether you burn fat or store it, are insatiably hungry or not, have cravings, enjoy balanced energy, age fast or slow, or maintain a state of health or disease. The power of your choices to impact hormonal balance is profound. Sleep, more than any other choice, has the power to balance your hormonal software for the coming day.

Sleep, the ancient fat regulator

Before getting to the specifics of how sleep elevates fat burning, it is important to clarify what we mean by weight loss.

We have all heard of calories and most in the fitness world feel calorie burning is the end all be all of weight loss. The first thing to understand is weight loss is an inaccurate descriptor of what most desire. Fat loss is what people really want, and weight loss does not necessarily equal fat loss.

That is why a focus on calories is so misleading because the type of calories burned, whether fat or sugar, is what is most important.

Hormones determine how much and what type of calories will be burned. Most people’s bodies are programmed to burn sugar and conserve fat.

This is an ancient survival mechanism that evolved to help our ancestors survive periods of famine. For almost all of human existence, food was not guaranteed, and those who were able to conserve fat easily fared better.

However, there are and always have been environmental signals that told the body to burn fat. Light and sleep are two important major determinants.

Why does sleep have this effect?

Consider the role light and sleep has played in our evolution as humans. We have evolved with the seasons.

Summer days are longer, brighter, and accompanied by abundant food.

Winter days have longer nights, colder days, and less food.

This may seem obvious, but before the amenities of artificial light, heat, and readily available processed foods, the only option at night was to sleep.

Summer and winter in the natural world send distinct and clear signals to a mammal’s physiology.

In the case of summer, the lengthened days meant elevated stress hormones like adrenaline and cortisol. The excess food meant higher amounts of insulin to signal fat storage and leptin to increase hunger.

The whole goal of summer is to reproduce and then eat as much as you can to get fat for the coming winter.

As fall approaches, the body has been exposed to high amounts of stress hormones, insulin, and leptin for so long it becomes resistant to their action creating a unique state where the ability to use fat or sugar for fuel is compromised.

Sound familiar?

This is the modern-day equivalent of what doctors call metabolic syndrome.

To ancient man reaching this state of hormone resistance (which would not have been nearly as forceful as today’s metabolic resistance) probably provided a survival benefit through winter. Without high sugar, blood fat, and ample fat deposits, the chances of surviving a long cold winter were diminished.

For a mammal wanting to get through the long winter, hormone resistance can be seen as good because it means the body is now nothing but a fat-storing machine.

By the time winter dawned historic humans would have shown a decreased ability to use fat for fuel, lack of motivation, depression of all body functions, and fatigue.

This is exactly the response needed to induce hibernation in a harsh prehistoric winter. A jovial energetic caveman with low body fat would not have lasted long in a harsh prehistoric winter.

The term “hibernation” here is used in a relative sense. Humans do not hibernate like bears but do show metabolic adjustments that resemble aspects of hibernation in animals (i.e. increase reverse thyroid hormone, insulin resistance, high blood sugar, etc.).

Depression and hypersomnia (increased sleep) are also present. Winter may have been our prehistoric savior. The shorter days and longer nights of winter forced prolonged periods of sleep.

Sleeping throughout the winter and going longer periods without food reversed the hormone resistance that was so prevalent in the late summer months and fall.

Less light exposure, complete reliance on animals for food, and prolonged sleep-induced a new hormonal program that turned on all the fat-burning genes.

By the time spring returned, the body was primed for action and burning through its fat stores at an accelerated rate.

The problem for modern man is we have unwittingly created an environment that mimics many aspects of summer. In this way of seeing things, we have created a summer on steroids that never ends. We have a constant and steady supply of sugar-rich foods.

We keep the temperatures stable through heating and air conditioning. And most importantly, we extend our days and decrease our sleep through exposure to artificial light in the form of TV, computer, and the light bulb. In this “artificial summer”, winter never comes, yet we continue to respond as if we were in the natural world of revolving seasons.

Leptin, insulin and cortisol run a hormonal program instructing us to eat as much as we can to get fat for the coming winter. The result? We get fatter, more tired, and more depressed. Sleep is the way out.

Does science support sleep like a fat burner?

Maybe you are wondering if this theory holds up in the scientific world. Is there any objective data to support what we are saying?

One study published online at the Public Library of science illustrates how sleep is connected to hormones that control appetite.

This study published December 7th, 2004 looked at 1,024 subjects and their sleep and eating habits. In subjects who slept less than 7 to 8 hours, a significant increase was noted in body mass index (BMI) and appetite.

These short sleepers ate significantly more and weighed more than those people who slept longer. The study also showed that leptin and ghrelin, two key hormones regulating appetite, were the major reason for this finding.

Another study bolsters the fact that light and lack of sleep are related to obesity. This study published in the June 2006 International Journal of Obesity, was a very comprehensive study looking at all the factors related to the increasing prevalence of obesity. In addition to the well-recognized connection between diet and exercise, this study found something interesting and unexpected. It found that deficits in sleep were a major predictor of weight gain and obesity.

This study also showed that heating and air conditioning may be playing a role, lending some support to the idea that human avoidance of natural factors such as light and temperature may lead to “hormonal confusion” as to how to manage our fat stores.

The two studies above, and others like them, make the hypothesis of this “artificial summer” not seem as far fetched. Key metabolic hormones involved in fat metabolism are continuously being shown to be impacted by sleep deficits.

There are many other studies on circadian rhythm, sleep, and hormone balance, and increased appetite in the sleep-deprived.

The important thing to remember is that you don’t need science to tell you what makes sense intuitively.

Most people know that if they get a good night’s rest, they are more likely to feel energetic, motivated, and make better choices. However, it is not always easy to know exactly what you can do to insure you get the most fat-burning potential from your sleep.

Choosing sleep

It all starts with your choices.

Don’t get the wrong idea, we are not telling you to go hang out in a cave for three months and hibernate.

We realize the demands of modern life.

We know you are busy, work hard, exercise, and try to find time to do the things you enjoy.

However, we also know that if you are serious about fat loss, you will need to consider some changes.

You have to ask yourself what is more important; do you want to burn fat, or watch your favorite late-night TV show?

Frequently people do not feel tired and take that as a sign they should stay up until they can go to sleep.

This is the wrong choice.

How do you think your body is going to feel when you feed it high sugar foods all day and bathe it in artificial light?

It is going to feel like it is summer.

What do animals feel compelled to do in the summer?

They want to find food and be active.

Now, admittedly we are exaggerating a bit here, but hopefully, this analogy drives home the importance of what we are saying.

Have you ever wondered why people who sit down in front of the TV at night always feel compelled to make their way to the refrigerator?

Perhaps it is just a habit, but light and other factors are playing a role as well.

Feeling tired is no longer a reliable indicator of the need for sleep because everything in the environment is sending the hormonal signal to stay awake. The only way to change this is to make different choices.

Technology can help.

Using dimmers on your lights and computer screens can decrease stress hormones at night. Using candles is another option.

DVRs and other devices are available to record your favorite late-night TV shows, so you can go to bed closer to sundown. There are all kinds of ways to send your body proper signals and rewrite your hormonal software programs.