Does Drinking Water Before Bed Help You Lose Weight? + 6 Great Benefits

Among the abundance of weight loss advice, there is one weight loss tip that seems to be one of the few commonalities between all of the various weight loss diets: drinking more water can help you lose weight.

But, does drinking water before bed help you lose weight, or can you gain weight from drinking water at night? Will drinking warm water before bed burn fat while you sleep, or is drinking ice water before bed for weight loss better?

In this guide, we will discuss the benefits of drinking water for weight loss, look specifically at whether drinking water before bed can burn fat while you sleep, and whether it is better to drink ice water vs warm water before bed for weight loss, ultimately answering your question, does drinking water before bed help you lose weight?

We will look at: 

  • Does Drinking More Water Help You Lose Weight?
  • Does Drinking Water Before Bed Help You Lose Weight?
  • Can You Gain Weight By Drinking Water Before Bed?

Let’s get started!

A person drinking water before bed.

Does Drinking Water Help You Lose Weight?

Research suggests that roughly 30 to 60% of adults in the United States increase their water intake when they are trying to lose weight.

However, as we are all well aware, there are many crazy and ineffective weight loss diets and weight loss hacks, so just because many people try drinking more water for weight loss doesn’t necessarily mean that drinking water to lose weight actually works.

Furthermore, fewer people talk about whether drinking water before bed increases weight loss or if drinking water before bed can cause you to gain weight.

With that in mind, we’ve gathered the research about the benefits of drinking water for weight loss and tried to look specifically at drinking water before bed for weight loss, and some of the results are encouraging. 

It’s important to establish upfront that although there are potential weight loss benefits of drinking water, just trying to drink more water before bed or trying to increase your water intake throughout the day as your only approach to weight loss will likely not be successful. 

If you want to lose a lot of weight, you will need to create a caloric deficit (a net negative balance between the number of calories you are consuming in the foods and beverages relative to the number of calories you are burning in a day).

A person drinking a bottle of water.

Although water should be part of your healthy weight loss diet and lifestyle program, when you want to lose a significant amount of fat, in addition to increasing your water intake, you will need to make other lifestyle changes.

These changes include reducing your caloric intake with a healthy diet and getting more exercise and physical activity on a consistent basis.

Drinking water can support weight loss, boost your energy levels, and improve your health, but it’s not going to be enough of a weight loss strategy to overcome a poor diet and sedentary lifestyle that results in a caloric surplus (eating more calories than you are burning).

Furthermore, while some people try to drink a gallon of water a day to lose weight or take on an extended water fasting diet, drinking too much water, particularly when following a very restrictive diet or not consuming any electrolytes, can be extremely dangerous.

Drinking an excessive amount of plain water can dilute your sodium and other electrolyte levels to dangerously low levels, resulting in a potentially fatal condition known as hyponatremia, along with other health problems.

Therefore, the disclaimer when we are discussing drinking “more” water for weight loss or drinking water before bed for weight loss is that you are drinking a reasonable amount of water and following a balanced diet and/or adding electrolytes to your water so that your electrolyte levels do not become depleted.

A person drinking a glass of water.

Does Drinking Water Before Bed Help You Lose Weight?

There are various ways in which drinking more water is associated with weight loss, but most of the benefits of drinking water for weight loss are not specifically linked with drinking water before bed to lose weight. 

In other words, there isn’t an additional temporal benefit of drinking water at bedtime for weight loss that accelerates the benefits of drinking water for weight loss relative to drinking water at any other time of the day.

That said, drinking water before bed still likely provides many of the same weight loss benefits as drinking water in general.

The good news is that in addition to anecdotal evidence about water weight loss benefits, there is scientific evidence that suggests that increasing your water intake can potentially help you lose weight and keep the weight off.

The most significant weight loss benefit of drinking water pertains to those who are swapping out caloric beverages for water.

A glass of water next to a laptop.

Because fat loss requires creating a caloric deficit, and water contains zero calories, swapping a caloric beverage for plain water will reduce your daily caloric intake.

You will lower your intake by however many calories you are drinking with sweetened beverages, such as soda, fruit juice, sports drinks, energy drinks, flavored milk and other milk products, sweetened coffee drinks, etc.

Drinking more water to prevent dehydration also improves your overall health and the physiological functioning of your body systems, according to the Centers for Disease Control and Prevention (CDC).

This, in turn, can support weight loss because if your body is functioning optimally, you will feel better, have more energy, and less inflammation.

Dehydration is one of the main causes of constipation, so ensuring that you are drinking enough water will help your body eliminate waste.

This doesn’t necessarily mean that you are losing fat when you drink more water, but bulking up and passing stool along can decrease bloating and weight gain due to constipation.

Bottles of water.

Sometimes, a large bowel movement can make a big impact on how flat your stomach looks and, of course, how well you feel!

Plus, according to some scientific estimates, approximately 75% of Americans are chronically dehydrated.

While you might be inclined to think that slight dehydration isn’t contributing to any of your physical symptoms or weight problems, studies have found dehydration of just 1-2% can cause fatigue.

Less energy means that you will be less inclined to work out! Dehydration can also cause headaches, difficulty concentrating, joint pain, hunger, lightheadedness, and more.

Evidence suggests also that water increases fullness, potentially decreasing appetite and caloric intake. 

Drinking water may also boost metabolic rate through a process called water thermogenesis; basically, this means that you may burn a few more calories by drinking water, particularly if the water is very cold.

Ice water.

Therefore, drinking ice water before bed may support weight loss even more than drinking warm water before bed.

Your body wants to maintain temperature homeostasis, so when you drink ice water, additional calories may be expended to increase the temperature of that cold water before it enters circulation.

As mentioned, there is little evidence to suggest that drinking water before bed causes more weight loss than drinking water at any other time of day.

However, there are two possible ways that drinking water before bed may potentially increase weight loss:

One possible way that drinking water before bed may support weight loss is because drinking water helps your body regulate body temperature better. 

Staying cool at night can help you sleep better.

Poor sleep is associated with increased appetite, reduced metabolic rate, cravings for sugary foods, low energy and poor motivation to exercise, hormonal imbalances, and increased levels of cortisol, all of which can contribute to fat gain and can make weight loss more difficult.

A person drinking a bottle of water.

One study found that drinking more water in general improved mood, feelings of well-being, a sense of calmness, and positive emotions.

If you are more calm, you will likely sleep better.

Of course, the flip side is that if you are drinking too much water before bed, you’ll need to get up and use the bathroom one or more times per night, which will decrease your quality of sleep—it’s a balancing act for sure.

The general advice is to try to do most of your hydrating during the day, cutting back significantly on how much you are drinking in an hour or two leading up to bed.

Keep track of your hydration over the day by using a refillable water bottle that keeps your water cold. 

We love HydroFlask water bottles and tumblers. HydroFlask bottles keep cold water cold and hot beverages hot all day.

We love that you can even customize the look of your water bottle so that you feel more motivated to drink throughout the day.

The HydroFlask water bottles don’t leak no matter what you do, so you can toss them in your gym bag, work bag, or store them on your desk next to your computer without worrying.

A person pouring a glass of water.

Can You Gain Weight By Drinking Water Before Bed?

It may seem like a bit of a silly question, but some people find themselves drinking water before bed and then seeing their weight increase on the scale the next morning, triggering questions like, “Can drinking water before bed cause weight gain?”

The answer here is yes, but with a very bold and big asterisk.

Yes, technically, drinking water at night can cause your weight to increase, but this is your overall body weight, not body fat.

Plain water contains zero calories, so it is impossible to gain fat by drinking any amount of water at any time of the day or night.

That said, drinking water before bed or during the night can increase your body weight, particularly if you had a salty or high-carb meal before bed because your body will then likely retain the water that you drink at night rather than excreting it in urine.

A person drinking a bottle of water.

Foods high in sodium, sugar, and carbohydrates, in general, cause water retention.

Therefore, if you drink water before bed or during the night after eating these types of foods, you will likely find that you do weigh more in the morning even if you pee because you will excrete less of the water, and your body water weight will be higher.

This water weight will be lost when you burn through the glycogen or drink more water, allowing your kidneys to excrete water weight from salty foods.

Similarly, if you drink calorie-free flavored water before bed or drink regular water at night and add electrolyte powders that have salt, sugar, or artificial sweeteners, you may gain water weight overnight from water retention.

For support with helping you drink more water to lose weight, try our 14-day weight loss challenge by drinking more water here.

A bottle of water.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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