The Science of Hydration and Weight Management

About 60% of the body is water which is distributed in multiple compartments, such as the blood. This clear liquid is vital for life. It plays a role in almost all bodily functions. But did you know that water also has weight loss benefits?

Most people think that reduced food intake and increased exercise are the key drivers of weight loss. However, it’s important to know that proper hydration can also help you lose weight.

Research suggests that water is a natural appetite suppressant. In addition, water has zero calories and can control your liquid calorie intake. Moreover, drinking water has been found to boost metabolism and burn fat. In some cases, even hunger can be mistaken for dehydration.

It’s worth noting that sipping on water alone will not help you lose weight. However, it can definitely support your weight loss goals while promoting your overall health.

Please keep reading to learn more about the connection between water intake and weight loss. We’ll also tell you how much water you should drink to lose weight.

How Drinking Water Affects Calorie Burn and Appetite

Natural Appetite Suppressant

When you drink water, your stomach feels fuller. This gives your brain the signal to stop eating. Therefore, drinking water can reduce the total number of calories you consume at mealtimes.

Studies have found that drinking water before meals helped dieters lose weight. For example, when obese individuals drank about 500-600 mL of water immediately before meals, they had 22% decreased caloric intake.

So, when you are getting ready for a big meal or about to reach for an unhealthy snack, try drinking a glass of water instead. You may find that your body has confused hunger for thirst and your hunger pangs go away after drinking water.

Looking to cut down on your caloric intake? Check out our blog: Portion Size Guide: All You Need To Know.

Liquid Calorie Intake

It’s not only sugary snacks and junk foods that are high in calories. Many commonly enjoyed beverages, such as carbonated and sparkling water, regular bottled soda, juices, shakes, and caffeinated beverages, are calorie-dense. Water contains zero calories. Therefore, adequate hydration with water can help you lose weight by replacing calorie-rich beverages with a zero-calorie drink.

Metabolism

Drinking water can increase your resting energy expenditure. This is also called the basal metabolic rate and is the amount of calories you burn at rest. Studies have found that drinking 500 mL of cold water increases metabolic rate and may burn calories faster. Cold water is particularly effective in revving up your metabolism because it forces the body to work harder for thermogenesis (to generate heat).

Fat Burning

The process of breaking down fat molecules is called lipolysis. The body needs water to burn fat. This means drinking enough water can help your body metabolize the fats you eat. People who have unhealthy fat percentages on body composition scores might see some weight loss benefits when they begin drinking water.

Efficient Workouts

Hydration is important to get the maximum benefit from your workouts. Drinking water helps your joints and muscles function properly. Plus, you need to drink water to replace the fluids you lose through sweat.

Electrolyte imbalances can cause muscle cramps. Water dissolves electrolytes like sodium, potassium, and magnesium and transports them to muscles where they are used during muscle contractions. Learn more: What Is the Best Magnesium Supplement for Sore Muscles?

Therefore, water lowers your chances of experiencing muscle cramps after exercising and improves your performance levels. Staying hydrated helps you stick to your workout schedule, which promotes weight loss.

Waste Removal

Water helps the body remove waste, both in the form of urine and stool. Staying hydrated increases urine volume and makes stool softer and easier to pass. This can help you feel lighter and more energetic after a bowel movement. Passing a larger volume of urine can help reduce water weight.

Motivation and Stress

Dehydration can cause fatigue, dizziness, drowsiness, and reduced alertness. Research has also shown that dehydration increases cortisol (stress hormone) production in the body. Check out: Are There Supplements to Reduce Cortisol (Stress Hormone)?

How does this help you lose weight? Water helps you stay hydrated, which in turn can prevent dehydration. This can lower stress levels and help you stay motivated to stick with your diet and exercise plan.

Debunking Myths: Water's Limitations in Weight Loss

It’s important to understand that while drinking water has overall health benefits and can support weight loss, it is not a magic bullet. Nutrition experts warn that while sipping water may help you burn a few extra calories, it is not a substitute for diet and exercise. It’s best to look at water as one part of your weight loss journey and not the sole driver of your weight loss efforts.

Factors Influencing Daily Water Intake

Body Weight and Composition

Your daily water intake varies based on your body composition and weight. The general rule of thumb is to drink one ounce of water for two pounds of body weight. So, if you weigh 150 pounds, your aim should be to drink 75 ounces (2.2 liters) of water every day.

The amount of water in your body is related to your body composition. Fatty tissue contains less water than lean tissue. Women have more fatty tissue than men. Therefore, the average adult female has 55% water in her body, while the average adult male has close to 60%.

Research has shown that higher levels of water intake and water balance in the body are associated with a lower body mass index and healthier body composition.

Activity Level and Energy Expenditure

Water needs vary depending on activity levels. After you work out, you need to replenish lost fluids by drinking more water. This is the best way to replenish fluids since water contains zero calories. However, people who do intense workouts and sweat a lot may benefit from sports drinks that also replace lost electrolytes.

A good rule of thumb is to drink small amounts of water (150-300 mL) every 15-20 minutes during exercise. The volume of water intake can be adjusted based on your sweating rate.

Environmental Conditions and Body Temperature

If you are working outdoors in the heat, dehydration can lead to heat stroke or heat exhaustion. This is because when you are dehydrated, you cannot sweat to cool your body, causing your body temperature to rise to dangerously high levels.

The Centers of Disease Control and Prevention (CDC )recommends drinking 8 ounces of water (1 cup) every 15-20 minutes or 24-32 ounces (3-4 cups) every hour that you are outdoors in hot weather.

You should start drinking water before you begin to feel thirsty. By the time you are thirsty, you have already fallen behind on fluid replacement. Also, it is more effective to drink smaller amounts of water at regular intervals rather than drinking large amounts of water infrequently.

Guidelines for Water Consumption to Aid Weight Loss

Average Individuals

The recommended amount of water you should drink daily is 64 ounces per day for an average adult. This is equal to about 1/2 gallon, 2 quarts, 2 liters, or 8 cups a day.

Interestingly, the CDC estimates that less than half of all adults in the US meet this recommended level of daily water intake.

While 64 ounces of water daily is a good starting point, you should adjust the amount of water consumed based on thirst. Go ahead and drink more water if you are still thirsty after drinking 64 ounces. However, if you feel quenched with less than the recommended amount, you don’t need to overdo it.

Overweight Adults

People who are overweight or obese have higher water needs than people who are at a healthy weight. As mentioned above, experts recommend drinking half your weight in ounces. Therefore, if you weigh 200 pounds, your daily water intake should be 100 ounces (about 3 liters or 12.5 cups) a day.

Active Individuals

If you work out regularly, you need to increase the amount of water you drink daily. The recommended 64 ounces a day may not be sufficient to keep you properly hydrated. Additionally, drinking the following amounts of water is recommended:

17-20 ounces (500-600 mL) of water 2-3 hours before exercise.
8 ounces (250 mL) 20-30 before starting exercise or during warm-up.
7-10 ounces (200-300 mL) every 10-20 minutes while exercising.
8 ounces (250 ml) within 30 minutes of finishing exercise.

The Impact of Drinking Water Before Meals

Research has shown that in middle-aged and older adults, in combination with a reduced-calorie diet, drinking 500 mL (approximately 16 fl oz or 2 cups) of water before each main meal of the day leads to consumption of 75-90 fewer calories during that meal and about 2 kg (5 pounds) greater weight loss over a 12-week period compared to diet alone.

There are plenty of creative ways to incorporate more water into your diet. The following list can help get you started:

Create Flavorful Water

It’s easy to make your own delicious sparkling beverages by infusing a pitcher of cold water with fresh herbs like mint or cucumber, lime, or orange slices. This makes drinking water more enjoyable. It encourages you to drink more than you would if it were plain water.

Eat Water-Rich Foods

Certain fruits and vegetables have a high water content. Eating them is akin to drinking lots of water. For example, lettuce and celery are 95% water and watermelon and cantaloupe have 90% water content. Other water-rich fruits and vegetables include tomatoes, radishes, zucchini, apples, and pineapples.

Avoid Sugary Beverages

The number of calories in each drink varies. You can stay adequately hydrated and support your weight loss efforts by choosing low-calorie drinks. Avoid sugary drinks like regular sodas and sugar-sweetened juices. Instead choose water, diet soda, or sugar-free juice.

Spice It Up

Adding some spice to your food may encourage you to drink more water in an effort to calm your mouth.

Drink Water Before Meals

Drinking one to two glasses of water before each major meal can help you meet your daily water intake goals. It may also support your weight loss journey by making you feel fuller and curbing your appetite.

Carry a Refillable Water Bottle

Taking a reusable water bottle with you everywhere can serve as a visual reminder to keep up with your water intake throughout the day.

Track Water Intake

You can set a daily water goal in a tracker app on your smartphone. This will help you see how you’re doing and become motivated to increase your daily water consumption. Tracker apps also have alarms that remind you to drink water at regular intervals throughout the day.

Consequences of Inadequate Hydration

Dehydration can increase your risk of health conditions such as high blood pressure and kidney stones. In terms of weight management, research has shown that adults who are inadequately hydrated have a higher body mass index and higher chances of being obese compared to adults who are well hydrated.

Signs and symptoms of dehydration include:

Extreme thirst
Dry mouth
Fast breathing
Fast heart rate
Low blood pressure
Fever
Reduced urine output and dark urine (instead of the usual light yellow)
Drowsiness, confusion, irritability

Dangers of Overhydration: Understanding Hyponatremia

Drinking plenty of water every day not only supports weight loss but is good for overall health. However, drinking too much water can be dangerous. It can dilute your blood and lead to hyponatremia (low sodium levels). This is called water intoxication, and it can cause brain swelling, seizures, and even coma.

Doctors warn against drinking more than 48 oz (1.4 liters) of water or other fluids per hour. Doing so can result in a medical emergency due to dangerously low sodium levels in your blood.

Balancing Fluid Intake: Recognizing Your Body’s Signals

Your body is your best guide to proper hydration and drinking enough water. Listen to the signals your body sends you and adjust the amount of water you drink accordingly.

For example, if you are thirsty, tired, dizzy, and peeing less than usual, you may be dehydrated and should drink more water.

On the other hand, if you drank a lot of water very quickly and have symptoms such as nausea, vomiting, headache, low energy, confusion, muscle cramps, or seizures, you should seek emergency medical care as you may have water intoxication.

Beyond Water: Comprehensive Strategies for Weight Loss

The Role of Diet: Calorie Intake vs. Energy Expenditure

The most effective way to lose weight is to create a calorie deficit in your body. This means that your calorie intake should be less than the energy you spend. You can achieve this by eating a reduced-calorie diet to limit caloric intake and increasing exercise to increase energy spent.

Importance of Exercise: How it Complements Hydration for Weight Loss

When you are trying to lose weight, doing more physical activity increases the number of calories your body burns for energy. When you combine this with a reduced-calorie diet, it creates a calorie deficit and results in weight loss. Hydration can complement diet and exercise in supporting weight loss.

Lifestyle Changes: Sleep, Stress Management, and Behavioral Adjustments

Poor sleep can disrupt hormone levels, increase appetite, and lead to weight gain. Therefore, good quality sleep is important to support your weight loss efforts. You should aim to get 7-9 hours of restful sleep each night.

Stress can lead to weight loss in some people and weight gain in others by affecting hormone levels and appetite. You can manage stress levels with healthy habits such as meditation, deep breathing, and yoga.

Behavioral adjustments in your eating habits can help you lose more weight. For example, eating only when you’re hungry, eating slowly, and planning healthy well-balanced meals ahead of time.

Common Questions

How much water should I drink to lose weight in 3 days?

It is not possible to lose weight in 3 days by drinking more water. You can, however, try drinking more than the recommended amount of 64 ounces of water a day, over a period of several weeks to months. This can increase satiety and reduce appetite, thus supporting your weight loss goals.

How to lose 5 pounds of water weight in 3 days?

Always consult a healthcare provider if you are trying to lose water weight quickly. Some of the things that may help include:

Increased water intake
Increased potassium intake
Decreased sodium intake
Decreased carbohydrate intake
Increased exercise
Raising feet above the level of the heart
Wearing compression socks
Taking diuretics (medications that cause increased urination)

How to lose 10 pounds in 10 days by drinking water?

It is not usually possible to lose 10 pounds in 10 days by drinking water. Drinking too much water can be dangerous and may result in a medical emergency due to low sodium levels. You can try drinking about 16 fl oz of water before meals to make you feel fuller, stimulate metabolism, and burn body fat. This may result in weight loss to the tune of 5 pounds over a 12-week period.

Can you lose 3 pounds of water weight in a day?

Water weight can make your total weight fluctuate by 1-5 pounds a day. If you want to lose 3 pounds of water weight in a day, talk to your healthcare provider. They can suggest safe ways to accomplish this.