Does drinking water help you lose weight?

Drinking water can help you lose weight, but there’s more to it than just that. Research shows that water intake might facilitate weight loss, but it won’t work on its own. In other words, you also have to maintain a healthy lifestyle (think: nutritious diet, regular exercise) to lose weight. 

Read on to learn more about how water can contribute to weight loss, and how much water to drink per day. 

Yes, drinking water can help you lose weight, but it doesn’t automatically cause you to shed pounds. It’s just one piece of the weight loss puzzle that you need to pair with other healthy choices, such as eating a healthy diet and exercising regularly. 

Research suggests a potential connection between increased water consumption and improved weight loss. However, there are no guidelines on how much water you need to drink to lose weight.

But exactly how can water help you lose weight? Let’s unpack some details. 

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There are a few ways increased water intake may help with weight loss:

1. Decreased appetite

Data suggests that people who drink before eating may lose more weight. One study found that middle-aged and older adults who drank half a liter of water before each meal lost 44% more weight over 12 weeks than those who didn’t drink water prior to their meals.

In two small studies, older adults who drank 375–500 mL (1.5–2 cups) of water about 30 minutes before a meal ate fewer calories at that meal compared with when they did not drink water beforehand.

Other research in younger adults suggests that drinking 300 mL (~ 1.27 cups of water) before a meal may help you feel fuller and decrease your appetite.

2. Improved body function

On average, your body is 60% water. And enough fluids are essential for good health and virtually everything your body does. This includes many critical cellular tasks and chemical reactions.

When you drink enough water, you’re improving your body’s overall wellness and functioning — including the processes involved in weight loss, like metabolism, muscle function, lung function, and fat burning. 

3. Removing waste

You also need water to digest, process, and eliminate waste. For example, increasing the amount of water you drink can reduce bloating, improve water retention, and help you lose water weight. Holding on to too much water can add inches to your waist (but it’s temporary and different from gaining body fat).

Not drinking enough H2O may also lead to constipation, which can affect the number on your scale (if that’s something you are tracking).

4. Increased calorie burning

Drinking water may increase metabolism and help burn calories. Taking in about 2 cups of water may raise your metabolic rate (the number of calories you burn) by as much as 30% — at least in the immediate term. 

Animal research also points to water as a factor in fat breakdown or lipolysis. Some human studies point in a similar direction. One study suggests that drinking a little over 6 cups a day is linked to reduced body fat and overall weight loss. Overall, human studies have had mixed results, so water should not be seen as a direct fat-burning tool.

5. Enhanced exercise effectiveness

Physical activity is an integral part of the weight loss process. Drinking more water can maximize your exercise effectiveness, thereby supporting your weight loss journey.

Dehydration can decrease your ability to exercise effectively due to fatigue and a drop in muscle metabolism. Meaning, your muscles may produce and use energy less efficiently.  

6. Cutting liquid calories

Replacing sugary drinks such as sodas, energy drinks, and juice with water helps lower your liquid calorie intake, which can contribute to weight loss. 

One study even found that replacing diet beverages with water may increase weight loss in people who engage in a weight loss program. Other data suggest that people who drink more water are less likely to gain weight than those who don’t drink or drink less H2O.

The average adult should consume about 2.7–3.7 liters of total fluids per day, including fluids from beverages and food, but there isn’t a one-size-fits-all amount of water to drink to lose weight. Remember, burning more calories than you take in every day (aka a calorie deficit) is the most important key to weight loss. However, water can play a role in this.

How much water to drink per day

While you’ve probably heard the “8 glasses per day” recommendation, there isn’t a universal consensus on how much water you should drink daily. This is mainly because it depends on your body type, activities, and location.

As a general reference, many healthy adults get enough total fluid from about 2.7–3.7 liters (11.5–15.5 cups), including fluids from beverages and food.  A common rule of thumb is that about 20% of daily fluid intake comes from food. Based on that estimate, many adults need roughly 2.2–3.0 liters, or about 9–12 cups, of fluids from beverages each day.

This doesn’t mean you should necessarily be chugging pints of water at a time. The water you drink should be dispersed throughout the day, not imbibed all at once. 

Many people also get water from water-rich foods, such as milk, fruits, vegetables, and soups. In fact, you can get a lot of your daily H2O intake from fruits and veggies. Produce is not only packed with satiating water, but it also contains fiber, which fills you up and helps you control your food intake.

You can certainly use common-sense rules based on your context. If you exercise regularly, sweat a lot, live in a warm climate, or are pregnant or breastfeeding, drink a few extra cups of water each day. If you rarely exercise and live in a cooler climate, you probably don’t need to worry as much about drinking extra water. 

If you are unsure how much you should drink per day, ask your healthcare provider. People with certain medical conditions, such as heart failure or kidney problems, are sometimes asked not to chug huge amounts of fluids because water can build up, causing symptoms like swelling. 

When you take GLP-1s, you should aim to get the recommended amount of around 2.7–3.7 liters of total fluids per day.

Some research shows that GLP-1s may reduce thirst and fluid intake in certain settings, such as in people with primary polydipsia (excessive thirst). It’s not clear how much this applies to people taking GLP-1s for weight loss or diabetes. 

But even if you feel less thirsty, you still need enough fluids. If you’re drinking much less than usual, or you have vomiting, diarrhea, dizziness, dark urine, or signs of dehydration, check in with your healthcare provider.

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Many people don’t drink enough water, despite its numerous health benefits. Here are some tips to help you up your daily water intake: 

1. Drink when you’re thirsty.

2. Have a glass of water before every meal.

3. Set yourself a daily goal for water intake.

4. Download an app with reminders to drink water throughout the day.

5. Attach water intake to specific activities, like a cup before and after a workout.

6. Incorporate more soups and water-heavy foods into your meals.

7. Eat fruits and vegetables with high water content, such as tomatoes, watermelon, berries, celery, cucumbers, and lettuce — many of these foods also have the added benefit of being high in fiber. 

8. Carry a reusable water bottle and keep it near you during the day.

9. Flavor your water naturally with fruits or vegetables (e.g. lemon, strawberry, cucumber, etc.)

10. Exchange your soda, energy drink, and other sugary beverages for water whenever possible. 

While drinking water in and of itself isn’t going to lead to weight loss, staying hydrated can support your overall weight loss plan. How, exactly? Here’s what to remember: 

• Some research suggests water can help with weight loss by decreasing your appetite (especially when consumed before meals), improving overall body function, removing waste, increasing calorie burn, and enhancing exercise effectiveness. 

• While there’s no one-size-fits-all amount, many healthy adults get enough total fluid from about 2.7–3.7 liters per day, including fluids from beverages and foods. 

• However, how much water you drink also depends on your activity level, the amount you sweat, and your location (think: climate). 

• On top of drinking water, you still need to make healthy choices like eating a nutritious diet, regularly exercising, and following other weight loss-friendly habits to effectively lose weight.