How Much Weight Do You Lose Every Night: Interesting Facts

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Medically reviewed by Gopal Ramakrishnan, Ph. D

How Much Weight Do You Lose Overnight

Ever wonder how much weight you lose during your sleep? You might be surprised to find out that it can be up to 4 pounds! We all know that the more we exercise, the better our bodies function.

But did you also know that if you get enough sleep every night, your body will have a chance to repair itself and get rid of any toxins or waste products? If not, then this blog post is for you. We will talk about what happens when we do not get enough sleep, why it is so important, and some interesting facts about how much weight we lose each night.

So keep reading to find out some of the oddest facts that might result in you weighing a little less every morning.

How Much Weight Do You Lose Overnight?

You Lose A Bit Of Weight Through Breathing In Carbon Loss

Every time your body breathes out carbon dioxide and receives oxygen molecules in return, a single exhalation includes more than two ounces of escaping cells.

Each time you exhale, there is one extra oxygen atom making its way into the atmosphere with every breath attached to the carbon loss. That means that when you inhale through your nose and mouth, both provide you with a molecule of Oxygen (O2), we are simultaneously losing CO2, which is a heavier molecule.

The truth is that the weight of one carbon atom concerning your body weight is negligible, but it is still something considering you inhale and exhale hundreds of times when you sleep.

You Lose Water When You  Sleep Through Water Vapor

Another reason why you lose weight at night is the loss of the body’s water weight. We all exhale water vapor when we sleep, and here is how. The bedroom can be about 75 degrees at night, which means that when your breath enters the body, it pulls some of its moisture out with it as you inhale.

When this happens most nights, one might lose around 2% total weight during slumber time-just enough for those few hours without movement.

You lose some weight when you sweat at night

If you sleep for eight hours in a row, your body will naturally sweat out 200 milliliters. This is because the body temperature stays within the average range. When temperatures are mild, it is at about 85°F and more, but if it is hot outside or on hotter nights, we produce much more liquid through our pores. This is because evaporation occurs due to higher levels of heat energy released by moonlight hitting our skin, causing us to sweat.

When this happens, you need water to drink since not having enough fluids can cause headaches, hunger, weakness, dizziness, sluggishness, confusion, memory loss, weight gain, dehydration, and electrolyte imbalance.

Several factors can influence how much you sweat at night, including diet and exercise. If you just had spicy food, for instance—it is likely your body will lose more water weight as part of the digestion process. It does this to cool off from all those spice molecules seeping into every cell.

Night sweats could also increase during specific periods such as menopause or disease states like hyperthyroidism[1]. This is where there is too much thyroxine hormone produced by  your thyroid gland (which regulates metabolism). So in these circumstances, you lose more than that 200 ml of sweat in just one night.

So if we are to answer the question, how much weight do you lose through sweating? You will have to convert the 200 ml to grams which is essentially translated to 20 mg.

There is Significant Weight Loss Overnight Through Urination

The regular trips you take to the bathroom mean that you leave that small room a few grams lighter.

The thing about urination is that the older you get, the more urine you produce. And since urine can never be reabsorbed inside the body, the only way it has to go is out the body.

However, if you are amongst the elderly, your sleep might be impacted by a higher proportion of urine being produced at night. This is due to health conditions such as congestive heart failure and diabetes mellitus. These conditions can lead to increased water loss during sleeping hours and affect weight retention over time if left untreated or improperly managed.

How Healthy Sleeping Habits May Result In You Losing Weight

This may explain why weight loss is imminent when you sleep. Here are some explanations highlighting why sleep deprivation can counteract weight loss.

When you have healthy sleeping habits, you essentially sleep for 8 hours straight, right. But when you are not getting adequate sleep, you activate your hunger hormones. The researchers[2] found that when people were sleep-deprived, they wanted to eat high-carb snacks.

In one study at the University of Chicago[3], participants stayed up late working on a project without proper rest for over three days straight—their choices in food changed. The lack of sleep also meant that they opted for energy-dense foods with a high amount of carbohydrates.

Those with a regular sleep schedule were more likely than not to consume items rich in fat and sugar. But the ones with sleep deprivation still picked foods fitting typical American unhealthy diets- fatty and high-carb foods. Plus, there was a likelihood of the portions being more significant than the healthier size, which results in weight gain.

That said, if you have a sleep schedule that is on average 8 hours, your brain will not trigger your hunger hormones to crave food; thus, you will not have any weight gain as you sleep. And since you lose weight overnight through water and breathing, you will notice slight changes for sure!

How Sleep Is Linked To Slowing Your Metabolism?

When you get at least 8 hours of sleep, your stress levels are normal. But if you do not get enough rest, there is a spike in cortisol, the stress hormone. Cortisol then works to signal your body to conserve your energy to get fuel when you are awake. So in retrospect, the body holds on to the body fat as it gets ready to survive.

That said, when you do get into a proper sleep schedule in a fortnight, you lose a substantial amount of fat and weight. But if you do not, the amount of weight you lost from fat loss drops to a whopping 55%[4]. This effect is not because of more calories since they can essentially remain the same. It just means that you will feel hungrier faster and you do not get satisfied when you eat.

The link here to your metabolism is that with sleep deprivation, the rate slows down. And the results are felt when the body starts drugging the production of insulin that helps convert sugar to starch and other nutrients to energy. The effect is that the insulin sensitivity[5] in the fat cells went down by about 30%.

Now here is the kicker:

When your body responds poorly to insulin, processing fats from your bloodstream becomes an issue. So much so that the result is the body saving and storing instead of initiating a fat burn. So in retrospect, when you have bad sleeping habits, your metabolism is affected, making you gain weight instead of losing it.

Ways to Get Into A Healthy Sleep Schedule To Maximize Weight Loss

Inevitably, you will have to adopt a healthy sleep pattern if you actually want to know how much weight you have lost overnight.

It turns out that sleeping for fewer than five hours per night can be bad news in more ways than one. In fact, a study[6] found people who got less sleep were at greater risk of becoming obese compared to those whose nightly slumber lasted seven or eight hours on average.

The relationship between sleep and weight loss is an age-old one. The body’s natural hunger hormones[7], such as leptin and ghrelin, seem critical in this equation. When these signals are not received correctly due to insufficient slumber, they can throw off other aspects that affect appetite, including sweet cravings for food.

And here are a few ideas that can help you gauge fat loss and weight loss since you will be able to fall asleep quickly.

Watch your diet before you sleep

Whatever you eat truly affects your sleep quality. Avoid eating heavy meals and alcohol close to bedtime, which may cause heartburn.

Drink plenty of water in the day for hydration purposes – this will help keep your digestive system working at its best! And avoid soda drinks because they have a lot of caffeine that can stay with you long after 2 p.m., so be careful when choosing these types during later hours.

Get into a sleep routine

Getting into a sleep schedule will help your body know when it is at rest. You also need to create this bedtime routine and stick to it. If you find it hard to get a good night’s sleep, there are options like trying relaxation techniques like yoga, meditation, soothing music that will help you fall asleep gracefully.

Remove all the electronics inside your room

The light that comes off screens, including TVs, tablets, and mobile phones, can inhibit falling asleep quickly. At the same time, they act as distractors as you have to stay alert watching and scrolling, thus finding it hard to sleep. When you remove them from the bedroom or switch them off, you minimize the blue light they emit, resulting in less sleep.

 If you must have your devices in the bedroom, place them in sleep mode, and that only the essential calls awake you. Rather than that, keep them away. It would help if you got enough to sleep; otherwise, you mess with the entire body system. And this applies to both healthy young men and women too. You can use them when you get out of bed in the morning.

Good sleep is necessary for a weight loss plan and good health. So if you want to lose pounds in the long run, the only way is that your body gets enough rest.

Take Away

Even though weight loss concerning muscle mass while you sleep might not be viable, it still happens. You lose some pounds through carbon loss, sweat, and urination. That said, you still need to get quality sleep to give the body a fighting chance to lose about the same amount of weight as it would typically do. If not, you throw off some systems in the body, such as your metabolism and the production of hunger hormones.

So you need to follow the tips given above to get a good night’s sleep all through REM sleep to sunrise. That way, with exercise, diet, and sleep, you get to stay on track with your weight loss plan.

Medically reviewed by:

Mitchelle Morgan is a health and wellness writer with over 10 years of experience. She holds a Master's in Communication. Her mission is to provide readers with information that helps them live a better lifestyle. All her work is backed by scientific evidence to ensure readers get valuable and actionable content.

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