Drinking more water is often recommended as a useful weight loss tool. This article examines the evidence behind the claim that drinking 3 liters (or 12 cups) of water per day can help you lose weight.
Quick Answer
Drinking 3 liters of water per day can help with weight loss, but is not a magic bullet for losing weight. Drinking more water may help in several ways:
- It can increase feelings of fullness and temporarily boost metabolism, helping you eat less.
- It can replace high-calorie beverages like juice or soda.
- It helps the kidneys function properly, removing waste from the body.
However, the amount of weight lost directly from drinking more water is generally modest. To lose a significant amount of weight, you need to combine increased water intake with a healthy, calorie-controlled diet and regular exercise.
Does Drinking More Water Help You Lose Weight?
There is some evidence that drinking more water, including 3 liters per day, may help with weight loss:
- It increases feelings of fullness. Drinking water, especially before meals, can help fill up the stomach. This creates feelings of fullness and satiety, causing you to eat less.
- It boosts metabolism temporarily. Drinking cold water raises the resting energy expenditure for about an hour. This means the body burns slightly more calories after drinking water.
- It prevents mistaking thirst for hunger. Sometimes people eat when they actually feel thirsty. Drinking more water prevents overeating caused by thirst.
- It replaces high-calorie beverages. Substituting water for drinks high in sugar and calories like juice, soda, and other sweetened drinks results in fewer liquid calories.
Studies show that drinking water can assist with weight loss, but the amount of weight lost is generally modest:
- In a 12-week weight loss study, people who drank 34 oz (1 liter) of water before meals lost about 2.5 pounds more than the control group.
- In another study, dieters who drank 17 oz (500 ml) of water before meals lost 44% more weight over 12 weeks compared to dieters who did not.
- Replacing sugar-sweetened beverages with plain water was associated with lower calorie intake and less weight gain over time in large observational studies.
So while drinking more water, especially before meals, can provide some benefits for weight loss, the effect is relatively small compared to the impact of diet and exercise.
How Does Drinking 3 Liters per Day Help You Lose Weight?
Here are some of the ways that getting into the habit of drinking 3 liters, or 12 cups, of water per day may encourage weight loss:
Increases Feelings of Fullness
Drinking water, especially before meals, can help fill up the stomach. This stretches the stomach walls, creating feelings of satiety or fullness.
Studies show that drinking water before a meal reduces the number of calories consumed. In one study, dieters who drank 16.9 oz (500 ml) of water before breakfast, lunch, and dinner lost 44% more weight over 12 weeks compared to dieters who did not drink water before meals.
Because water is calorie-free, it can effectively replace higher-calorie beverages and fill you up without adding extra calories to your diet.
Boosts Metabolism
Interestingly, drinking cold water may temporarily raise resting energy expenditure. This is the number of calories your body burns at rest.
The effect is estimated to be an increase of 24-30 calories per hour for 1-1.5 hours after drinking 17 oz (500 ml) of cold water.
While the metabolic boost from water is modest and temporary, even small increases in metabolism can help facilitate weight loss when combined with a healthy diet.
Prevents Mistaking Thirst for Hunger
Thirst is sometimes confused for hunger. So occasionally, people eat when they just feel thirsty.
Drinking sufficient water prevents dehydration and ensures you do not mistake thirst for hunger. This can reduce overeating.
Replaces High-Calorie Beverages
Sugary drinks like soda, fruit juice, sports drinks, sweet tea, and other beverages high in sugar and calories are associated with weight gain and obesity.
Substituting water for any of these drinks results in reduced calorie intake, potentially supporting weight loss.
For example, replacing just one 12-ounce can of regular soda with water means skipping 140-150 calories.
Water Requirements for Weight Loss
Weight loss will occur when you consume fewer calories than you burn through a combination of diet and exercise. So how much water should you drink to maximize weight loss?
General guidelines recommend drinking at least 64 ounces (8 cups or 2 liters) of water per day for women and 80 ounces (10 cups or 2.5 liters) for men. This minimum amount is required to prevent dehydration.
To potentially aid weight loss, some sources suggest drinking up to 112 ounces (14 cups or 3.5 liters) of water per day for women and 128 ounces (16 cups or 4 liters) for men.
However, there is no strong research indicating you must drink a set amount of water to lose weight. Everyone’s water needs can vary based on factors like age, activity level, health conditions, and climate.
A good rule of thumb is to drink water when you feel thirsty and also drink an extra 1-2 cups with meals or snacks. You may need more water after strenuous exercise that causes heavy sweating.
If you notice your urine is dark yellow or there seems to be a constant urge to urinate, these are signs you need to drink more. But if your urine is mostly clear and pale yellow, your water intake is likely sufficient.
Tips to Drink 3 Liters of Water Per Day
Drinking 3 liters (12 cups) of water daily may seem like a lot. Here are some tips to help you get into the habit:
Carry a Water Bottle
Having water readily available makes it much easier to sip throughout the day. Carry a reusable water bottle with you at home, at work, and when running errands.
Set Reminders to Drink
Set a reminder on your phone, watch, or other device to prompt you to drink water at regular intervals, such as every 1-2 hours.
Track Your Intake
Use an app or journal to record how many glasses or bottles you drink each day. Tracking can help motivate you to reach your goal.
Choose Water Over Other Beverages
Opt for water whenever you are looking for something to drink. Pass on juices, sodas, coffee drinks, and other high-calorie options.
Add Slices of Fruit
For variety, add slices of citrus fruits, cucumber, berries, or other fruits you enjoy to your water.
Drink a Glass Before Meals
Drinking 1-2 glasses of water 30 minutes before meals can help fill you up so you eat less when you sit down to eat.
Make a Schedule
Schedule specific times you will drink glasses of water, such as 9 am, 11 am, 1 pm, 3 pm, etc. This can help hold you accountable.
Set Consumption Goals
Aim to drink a certain number of ounces or liters per day, week, or month. Slowly increase your goal over time.
Risks of Drinking Too Much Water
Is there any danger associated with drinking 3 liters of water per day? For most healthy people, this amount of water intake is not risky.
However, drinking too much water can cause potentially serious side effects in rare cases. Risks include:
- Hyponatremia – dangerously low sodium levels from too much water diluting the sodium in blood.
- Water poisoning – swelling of the brain from excessive water intake.
- Overhydration – flushing out too much electrolyte minerals from the body.
Those at greatest risk include endurance athletes and people with certain conditions like heart failure or kidney problems. Healthy adults are unlikely to experience water-related side effects at 3 liters per day.
But it’s wise not to go drastically overboard on water intake. Signs you may be drinking dangerous excess amounts include:
- Having to urinate every 15-20 minutes
- Urine that is completely clear and abundant
- Constant headaches
- Trouble concentrating
- Muscle weakness, spasms, or cramps
- Nausea and vomiting
If you experience any of these, cut back on water intake. Unless your doctor has advised otherwise, staying in the range of 2-4 liters per day is generally safe.
The Bottom Line
Here is a summary of the key points on whether drinking 3 liters of water per day will make you lose weight:
- Drinking more water can mildly increase metabolism, curb appetite, and replace high-calorie beverages.
- Drinking water before meals helps create feelings of fullness so you eat less.
- Studies show drinking 500 ml of water before meals can lead to greater weight loss.
- Replacing sugary drinks with water reduces calorie intake.
- General hydration guidelines suggest drinking at least 2 liters (8 cups) of water per day for women and 2.5 liters (10 cups) for men.
- Drinking 3 liters of water daily is safe for most people and may be beneficial for weight loss.
- But water alone won’t make you lose a significant amount of weight unless you also diet and exercise.
In conclusion, drinking more water can absolutely aid your weight loss efforts. But to lose a meaningful amount of weight, you need to combine increasing your water intake with reducing your overall calorie intake and getting regular physical activity.
Drinking 3 liters of water per day can help keep you hydrated, decrease calorie intake, and may encourage you to make healthier overall diet choices. But water consumption alone in the absence of diet and exercise is not a magic solution for weight loss.
