Staying hydrated is an important part of overall health, and some people find that drinking more water helps them lose weight. The recommended daily water intake varies between individuals based on factors like age, gender, activity level and climate. Many experts suggest drinking around 64 ounces (8 cups) of water per day as a general guideline for adequate hydration in adults.
How Much Water Should You Drink to Lose Weight?
There is no universal rule for how much water you need to drink to lose weight. Some people may need more or less than 64 oz per day depending on their individual needs. Here are some factors that determine water needs for weight loss:
- Age – Older adults may need less water than younger people due to decreased activity levels and slower metabolism.
- Gender – Men generally have higher water needs than women because they tend to have more muscle mass.
- Activity Level – Active individuals need more hydration to replace fluids lost through sweat.
- Climate – Warmer climates and summer weather causes increased water loss through sweat.
- Body Size – Larger, taller individuals need more water than petite people.
- Diet – Eating a diet higher in salt, caffeine or alcohol causes fluid loss and increases water needs.
- Health Conditions – Some conditions like diabetes or heart disease affect hydration needs.
The easiest way to determine your personal water requirement is to drink when you feel thirsty and observe if your urine color is light yellow to clear. Dark yellow urine usually indicates dehydration. Monitoring your weight on a scale, your energy levels and other signs of dehydration can also help determine if you are drinking enough water.
Does Drinking Water Help You Lose Weight?
Drinking more water by itself does not directly cause weight loss. However, staying well hydrated can support weight loss efforts in several ways:
- Helps Boost Metabolism – Some research found increased water intake can temporarily speed up metabolism by up to 30% for about an hour.
- Suppresses Appetite – Drinking water before meals can help you feel full faster so you eat less calories.
- Flushes Toxins – Staying hydrated helps your kidneys efficiently remove waste and excess fluid.
- Improves Digestion – Adequate water intake keeps things moving smoothly through your digestive tract.
- Increases Fat Burning – Proper hydration is essential for lipolysis, the breakdown of fat for energy.
- Boosts Exercise Performance – Drinking enough water helps your body handle the demands of exercise needed for weight loss.
While simply drinking more water alone won’t make you lose a significant amount of weight, combining increased water intake with a healthy diet, portion control and regular exercise can contribute to overall weight loss success.
What Are the Benefits of Drinking 64 oz of Water Per Day?
Drinking 64 ounces (8 cups) of water daily provides the following key health benefits:
- Maintains Fluid Balance – Adequate hydration keeps fluid levels in balance and prevents dehydration.
- Supports Kidney Health – Water helps flush waste from kidneys and prevents kidney stones.
- Aids Digestion – Water improves digestion and prevents constipation.
- Delivers Nutrients – Water is needed for nutrient absorption and transport.
- Regulates Body Temperature – Staying hydrated helps regulate body temperature.
- Lubricates Joints – Water keeps joints lubricated to prevent stiffness and pain.
- Boosts Cognitive Function – Even mild dehydration can impair focus, memory and mood.
- Boosts Exercise Performance – Water fuels muscles and replaces fluids lost while active.
- Promotes Heart Health – Adequate hydration supports healthy blood pressure and circulation.
- Reduces Risk of Infections – Water helps flush bacteria from the bladder to prevent UTIs.
As long as you don’t have any medical conditions like heart failure or kidney disease causing fluid retention, there are very few risks to drinking 64 oz of water daily. Most healthy adults can safely meet their hydration needs with this amount.
How Much Weight Can You Lose by Drinking 64 oz of Water Daily?
There isn’t a fixed amount of weight that everyone will lose from drinking 64 oz of water daily. The amount of weight loss can vary substantially based on the individual. Here are some factors that influence how much weight could be lost by increasing daily water intake to 64 oz:
- Starting Weight – People who are obese may lose more initial water weight than thinner individuals.
- Diet – People eating a high sodium diet tend to retain more water weight.
- Exercise Routine – Active individuals who sweat a lot stand to lose more water weight.
- Climate – Those in hotter climates will lose more water weight from increased sweating.
- Gender – Men generally carry less subcutaneous fat and lose weight faster than women.
- Genetics – Genetics play a role in how quickly people lose or gain water weight.
- Medications – Some medications like steroids or NSAIDs can cause fluid retention.
On average, drinking an extra 64 oz of water daily typically results in:
- 2 to 3 pounds of initial water weight loss in the first week
- 5+ pounds of water weight loss for obese individuals in the first week
- 1 to 3 pounds of fat loss when combined with diet and exercise
Keep in mind that weight fluctuations from fluid shifts tend to be temporary. Long-term fat loss requires a calorie deficit from diet and exercise. Drinking more water can support fat loss efforts but won’t directly cause substantial fat or weight loss on its own.
Should You Drink 64 oz of Water Fasting?
Some people drink 64 oz of water first thing in the morning on an empty stomach as part of an intermittent fasting regimen. Here are some things to know about drinking water fasting:
- May Temporarily Boost Metabolism – Drinking water upon waking may slightly boost metabolism for about an hour.
- Helps Hydrate After Sleep – Rehydrates your body after water loss through breathing and sweating overnight.
- May Suppress Appetite – Water fills up space in the stomach, which may reduce hunger.
- Improves Alertness – Hydration helps increase blood flow to the brain to improve mental sharpness.
- Contributes to Daily Intake – Gets a head start on meeting daily water needs.
There is limited evidence that drinking water first thing in the morning leads to significant weight loss. It may offer some temporary metabolic benefits, but does not directly burn a substantial amount of calories on its own. However, it can support intermittent fasting efforts by helping control hunger.
Potential Drawbacks of Drinking 64 oz Water Fasting
- May Cause Discomfort – Large amounts of water may cause bloating, nausea or headaches in some.
- Interrupt Sleep – Having to wake up to pee at night can disrupt sleep quality.
- Not Suitable for Everyone – Those with kidney disease or heart failure may need to limit fluid intake.
- Doesn’t Burn Many Calories – Drinking plain water doesn’t burn a significant amount of calories.
- Temporary Weight Loss – Water fasting leads to temporary water weight loss that will likely rebound.
As long as you tolerate it well, don’t have any medical conditions causing fluid retention, and allow time for bathroom breaks, drinking 64 oz of water upon waking is generally safe and may provide some temporary weight loss benefits.
Tips for Drinking 64 oz of Water Per Day for Weight Loss
Here are some tips to help you successfully drink 64 oz of water daily to maximize potential weight loss benefits:
- Carry a refillable water bottle to increase intake.
- Set reminders on your phone or smart watch to drink water throughout the day.
- Flavor your water with citrus fruits, cucumbers or herbal teas if you don’t like plain water.
- Drink a full glass of water before meals to help reduce appetite.
- Choose water over sugary drinks like soda, juices and sports drinks.
- Opt for water when eating out instead of high calorie beverages.
- Add extra water after exercise to rehydrate.
- Drink sparkling mineral water if you miss the carbonation of soda.
- Consume water-rich fruits and vegetables like tomatoes, berries and melons.
- Monitor your urine color to assess if you need to drink more water.
Staying well hydrated with 64 oz of water per day can help form healthy habits that support weight loss, especially when combined with a balanced diet and active lifestyle.
Can You Drink Too Much Water?
It’s rare to drink too much water if you have healthy kidneys that can efficiently remove excess fluid. However, drinking an extreme amount can be dangerous. Here are some risks of overhydration:
- Water Intoxication – Excessive water dilutes sodium in the blood leading to swelling, nausea, headaches and fatigue.
- Hyponatremia – Drinking gallons of water without adequate electrolyte intake causes low sodium levels.
- Brain Swelling – Hyperhydration increases fluid around the brain which can be fatal.
- Breathing Difficulty – Fluid accumulation in the lungs makes it hard to breathe.
- Fluid Imbalance – Kidneys can’t excrete large amounts of fluid fast enough.
To avoid overhydration, most healthy adults should not exceed 3-4 liters (100 to 140 oz) of total fluid per day from water, beverages and food. Athletes who sweat heavily may require more. The key is drinking when thirsty and limiting excess intake once your thirst is quenched.
Symptoms of Overhydration
Watch for these signs of potentially consuming too much water:
- Frequent urination
- Excessive thirst
- Dark or no urine
- Bloated or full feeling
- Nausea
- Vomiting
- Headache
- Confusion
- Fatigue
- Irritability
- Muscle cramps or weakness
- Seizures
If you experience these symptoms after drinking large amounts of water, seek medical attention immediately. Treatment may include IV fluids and electrolyte replacement.
Special Considerations for High Water Intake
Some people may need to be cautious about drinking too much water:
- Those with kidney disease or failure may need to limit fluid intake.
- People taking medications that act as diuretics, like hydrochlorothiazide, increase urination.
- Endurance athletes who drink while excessively sweating for prolonged periods.
- Elderly adults with decreased thirst perception may inadvertently over-drink.
- Young children who are offered too much water are at higher risk.
People with heart failure are also at increased risk for overhydration because the heart has a diminished ability to pump excess fluid from the body. Those taking certain psychiatric medications like lithium should be monitored for proper hydration.
Most healthy individuals with normal kidney function do not need to worry about consuming too much water if they drink based on thirst. But some populations may need guidance from a doctor on proper hydration.
Frequently Asked Questions
How can I drink 64 oz of water a day?
Tips to drink 64 oz of water daily include carrying a refillable bottle, setting reminders to drink water, drinking a glass before meals, choosing water instead of other beverages, and drinking water after exercise. Flavoring water and eating water-rich foods can also help increase intake.
When should you drink 64 oz of water?
Aim to drink water consistently throughout the entire day rather than drinking it all at once. Consume about 8 oz every 1-2 hours. Drinking a glass first thing in the morning and before meals can be an effective strategy as well.
Can you drink too much water trying to lose weight?
It’s rare but possible to overhydrate while trying to lose weight. Limit water intake to 100-140 oz daily, drink based on thirst, and avoid excessive intake if you have kidney disease or are taking medications that increase urination.
Does water weight come back after stopping 64 oz daily?
The initial water weight loss from increasing daily water intake to 64 oz may be temporary. Your body will likely adjust and retain fluid again if you stop drinking as much. For sustained weight loss, permanent healthy lifestyle habits are key.
Can you lose belly fat by drinking water?
Drinking more water can help temporarily reduce water retention and bloating to shrink belly size. But substantial fat loss requires a calorie deficit from diet and exercise. Drinking water alone won’t burn significant belly fat.
The Bottom Line
Drinking 64 ounces (8 cups) of water daily is a healthy target for most adults and may temporarily aid weight loss efforts through appetite suppression, metabolism boosting, fluid reduction and supporting exercise. However, increasing plain water intake alone is unlikely to cause significant permanent fat loss. To lose body fat, you need to combine drinking adequate water with reducing calorie intake from your diet and burning calories through exercise.
For lasting weight management, focus on developing overall healthy lifestyle habits with regular physical activity, nutrient-dense whole foods, sufficient sleep and stress relief. Aim to drink enough water to satisfy thirst, support your activities and keep your urine pale yellow. This is typically around 64 oz for most people, but individual needs vary.