Blog Diets Fasting Water Fasting Benefits: Sip Your Way to Wellness!

Water Fasting Benefits: Sip Your Way to Wellness!

For many years, fasting has been embraced for its dual benefits. It caters to the physical as well as spiritual, making it an important part of holistic healing. Even though weight loss remains the primary objective of fasting for many, it is widely adopted for its ability to boost self-discipline. Among all forms of fasting, water fasting stands out as a tempting option, especially in modern times.

Water fasting is a pretty straightforward plan. One has to skip all solids while only drinking water. It has become popular because people have witnessed visible positive impacts on their health after implementing it. But what exactly is water fasting?

Read this article to understand the basics of this diet and potential water diet benefits:

What is Water Fasting?

Water fasting is a type of fasting where you only consume water for a set time, without having food and drinks with calories. While water fasts usually last 24-72 hours, some may go far beyond that. Many individuals water fast for health or religious purposes, while some do it to prepare for a medical procedure. According to several studies, water fasting may help prevent heart disease and lower the risk of certain types of cancer (1).

That said, water fasting can also promote autophagy, a process where the old cells in your body are broken and replaced with newer cells (2).

What is The 3-day Water Diet?

The 3-day water diet is where you consume only water for 3 consecutive days without eating food or having other drinks in between. The process is to drink plain water to experience several water diet benefits. Most people drink 2-3 liters of water during a water fast. Although instant weight loss is one of the potential 3-day water fast benefits, such plans are not recommended and must not be done without medical supervision, as some individuals may encounter health risks during their fasts.

There is no hard or fast rule on how to start a water diet for 3 days. After 3 days of constantly having water, you must resist the urge to have a big meal, as this may make you feel uncomfortable. Instead, you should have a smoothie, or light broth, or divide your meal into smaller meals.

In fact, you should prepare for 3 days of water fasting by having nutritious, balanced meals before your fasting begins. This will help your body prepare for fasting and not experience powerful side effects, post-fast. The post-fast phase is an important one, as you must be careful with your diet. You may be at risk of refeeding syndrome, a risky condition in which your body undergoes rapid changes in electrolyte levels (12).

See also
16/8 Intermittent Fasting for Seniors: Benefits, Meal Plans, and Tips

While this post-fasting phase usually lasts a day, this may last longer for individuals who follow a 3-day water fast. With that in mind, it’s important to introduce your body to food slowly to avoid the risk.

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What Are The Benefits of Water Fasting?

Water fasting offers plenty of potential health benefits, making it popular among weight loss enthusiasts. Some of the notable 3-day water fast benefits are:

Lowers Blood Pressure

Water fasting might help lower blood pressure among individuals with hypertension or high blood pressure. According to a study, overweight individuals who fasted for 17 days experienced a significant drop in their systolic blood pressure (14). The study also showed improvement in levels of LDL or bad cholesterol.

Cause Weight Loss

One of the biggest possible benefits of a water diet is weight loss, as it initiates ketosis, in which the body burns fat and utilizes it for fuel. According to a study, individuals who fasted for 8 days lost an average of over 13 pounds (10).

water diet benefits  

Improves Blood Sugar Levels

Water fasting has been linked to improved insulin and leptin sensitivity, both of which are essential for metabolism. Insulin helps the body store nutrients, whereas leptin causes satiety (8). The higher the sensitivity, the better the efficacy of these hormones.

By being more insulin-sensitive, the body efficiently reduces blood sugar levels, and by being leptin-sensitive, the body better processes hunger and, in turn, lowers the risk of obesity.

According to a 2023 study, prolonged fasting i.e., 5-20 days, could significantly reduce blood sugar levels while improving insulin resistance (7).

Improves Heart Health

Among the many benefits of a water diet, one such potential benefit is improved heart health. Water fasting helps protect the heart against heart disease by reducing oxidative stress (9). Also, fasting water after a heart attack reduces the risk of high blood pressure, diabetes, and obesity.

Promotes Autophagy

Autophagy is an important process where the body breaks down old cells and replaces them with newer cells, rejuvenating the body. Autophagy protects against several chronic diseases like cancer, Alzheimer’s, or heart disease. Studies show that water fasting promotes autophagy, ensures longevity, and protects against metabolic diseases (4).

See also
A Beginner Intermittent Fasting Meal Plan to Fit Your IF Journey

Read more: Green Tea Intermittent Fasting: Benefits and Side Effects

What Are the Risks and Side Effects of Water Fasting?

Water fasting might be good for your health, but it also has some dangers. Since you are depriving your body of essential nutrients during a water fast, you may be at risk of malnutrition or worse. You may experience refeeding syndrome due to electrolyte imbalance.

It is, thus, important to consult a doctor or a registered dietitian before beginning water fasting. If you experience the following risks, these are the signs to stop water fasting.

Orthostatic Hypotension

If you are overhydrated due to water fasting, you may be at risk of orthostatic hypotension, a condition in which you experience a sudden drop in blood pressure when you stand up, making you feel dizzy or lightheaded, and at the risk of fainting (11).

Nutritional Deficiencies

If you fast for a long time with only water, your body might miss out on the important nutrients it needs to work properly. This could slow down your metabolism and mess with how your body usually functions.

Muscle Loss

If you are fasting for a long time you may risk muscle loss, as weight loss involves not only fat but also a little bit of muscle mass. Also, when you don’t get proper nutrition, your muscles may get weak and break down.

Weakened Immune System

Prolonged fasting may weaken the immune system, making the body more susceptible to infections. Moreover, individuals with eating disorders may avoid water fasting as it can trigger disordered eating. With these risks in mind, individuals with the following conditions must abstain from water fasting (16).

Pregnancy or Breastfeeding

Water fasting isn’t safe for pregnant or breastfeeding women because they need extra nutrients to support their babies. During a water fast, they might not get all the nutrients they need, which could be harmful to the baby’s health.

Eating Disorders

People who struggle with eating disorders should avoid water fasting because it could worsen their condition. Extreme diets like water fasting can trigger unhealthy eating patterns and behaviors in individuals with eating disorders.

Certain Ages

If you’re younger than 18 or over 75, it’s best to steer clear of water fasting. Your body needs all kinds of important nutrients every day to grow and develop properly. Skipping meals, especially without getting those essential nutrients, could interfere with your growth and overall health. You should stick to a balanced diet that provides you with everything you need to thrive.

See also
Intermittent Fasting Meals That Will Fit Your 16/8 Schedule


Water fasting isn’t recommended for individuals with type 1 diabetes. That is because fasting can lead to dangerously low blood sugar levels, known as hypoglycemia, especially when medications are typically taken with food. Without proper management, this could pose serious health risks for those with diabetes.

Can You Lose Weight from a Water Diet?

If you are wondering, “How to Lose Water Weight?”, check out water fasting and how to practice it. A well-planned water fast may cause weight loss, most of which is water weight. According to a study, individuals who followed the 8-day water fast lost around 13 pounds (10).

However, there are risks to extreme water fasting, such as malnutrition, so it is advised to follow a moderate water diet, such as intermittent fasting or alternate-day fasting as these methods allow you to consume meals, preventing you from malnutrition and helping you lose weight.

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Can You Go 40 Days With Only Water?

It might be possibleto 40 days following a water diet, but it is highly risky and not recommended. Fasting for 40 days straight can cause extreme changes in your body and may put you at risk of malnutrition or dehydration. As your body needs nutrients daily, restricting it to plain water only is not a good idea.

Worse, 40-day water fasting may be fatal, and some reports have noted that death can occur between 43-70 days of water fasting (6).

The only 30 day water fasting benefit is potential  weight loss. And this is what pulls more people. But, rapid weight loss is not a good idea, and you must consult a medical expert before starting extreme diets. On the contrary, you may do intermittent fasting for 40 days, coupled with solid meal plans. Also, individuals with certain conditions like pregnancy, diabetes, chronic disease, or children must refrain from 40-day water fasting.

water diet benefits  

What is The 7 Day Water Diet?

A 7 day water diet is an extended water fast where you only consume water and refrain from foods for a whole week. This type of fast is extreme and must not be done without medical guidance. Some of the 7 day water fast benefits include weight loss and detoxification.

See also
Fasting Detox: Foods And Drinks To Detoxify Your Body Safely

Preparing for a 7-day water fast is important to avoid any risks. The 36 hours before the 7-day water fast are critical.  So, you must prepare wisely by doing a 16-hour overnight fast for two days to get your body prepped for the 7-day fast. Consume light meals like fruits or vegetables and avoid processed foods to prepare your body.

Here’s what happens during the 7-day water fast (13):

Ketosis can start to take place after 12 hours, where the body breaks down fat and converts it into energy. At around 24 hours, autophagy takes place when old cells are broken and replaced with new cells. By 48 hours or the second day, the growth hormone levels can increase by up to five times. By 60 hours, insulin has the potential to drop to its lowest level, and by 72 hours, the body breaks down and generates new immune cells.

Once the 7-day water fast passes, it is important to replenish your body with essential nutrients. Try consuming balanced meals with proteins, high fiber carbs, and produce.

The primary potential 7 day water fast benefit is weight loss. Studies show that 7-day water fasting can help you to lose up to 1 pound per day (5). It also initiates autophagy, which helps prevent cancer and replaces old cells. Plus, water fasting regulates blood sugar levels and helps stabilize insulin levels.

Is It Safe to Fast for 30 Days?

Fasting for 30 days is a long time and requires medical supervision. Individuals with certain medical conditions, including diabetes, heart disease, or eating disorders, must refrain from fasting for 30 days. If you don’t have any health conditions, you might able to fast for up to 30 days, but it’s important to prepare your body for fasting by fasting for short periods before beginning the month-long fast.

Also, you should slowly refuel your body after completing the 30-day fast to avoid refeeding syndrome or potential side effects.

It’s important to note that water fasting may alter the water-mineral balance, which can cause issues like hyponatremia or low sodium levels, which may be fatal. Also, fasting water may increase uric acid levels in the body, which may be risky for individuals with kidney disease (17).

Prolonged water fasting may cause your body to store extra fat and slow down metabolism due to starvation. You must keep these risks in mind and only do prolonged fasting if your body allows it.

See also
Rules of Intermittent Fasting: How to Get it Right?

To reap the benefits of the 30-day fast, it is important to follow certain safety tips.

Have short fasting periods or do intermittent fasting before you begin prolonged fasting. Starting 30-day fasts right away will make you feel uncomfortable, nauseous, and hungry. Therefore, keep short fasts and break your fast with healthy meals.

Try to stay hydrated by consuming plenty of water before, during, and after your fasts. Try to get adequate rest and avoid strenuous activities while fast. You may indulge in light exercises like yoga or walking. Once you break your fast, avoid devouring food, as this may cause bloating. Instead, stick to light meals and consume slowly.

Eat nutrient-packed foods and avoid processed foods after your fasting period. Try to consume foods rich in fiber, proteins, vitamins, or minerals. Before you begin fasting, try to reduce your portion size and lessen meals throughout the day.

Lastly, if you have diabetes or any medical condition, talk to your doctor and only begin water fasting if your doctor approves.

How Much Water Should I Drink a Day to Lose Weight?

Consuming water daily may help with your weight loss goals. It is recommended to consume at least 1-2 liters of water daily to lose weight. The Academy of Nutrition and Dietetics recommends 9 cups of water for females and 13 cups of water for males daily (3).

When you have a hefty meal, your brain sends a signal of fullness, and you stop eating. When you drink more water, your stomach fills with water, which reduces space and makes you feel full quickly. When you drink more water, you replace it with sodas or beverages packed with calories. By eliminating these drinks, your caloric intake decreases, and you lose weight.

Read more: Intermittent Fasting and Running: A Winning Combination or a Terrible Mistake?

water diet benefits  


  • What happens if you only drink water for 30 days?

If you only drink water for 30 days, you have the potential to see rapid weight loss. However, this can be unsafe for many individuals and should be done with medical supervision. 

  • How many days can you go with water?

This capacity depends on your health and individual preferences. The recommended water fasting time is 24-72 hours, as this is considered generally safe.

Without water and food, an individual cannot live longer than 4-10 days. In the absence of food, the body utilizes stored fat and sugar as sources of energy. However, in the absence of water, the body may go into dehydration, and the kidneys may fail, which may be fatal.

  • Can you go 21 days with only water?

You may be able to  go for 21 days with only water as long as you don’t have any medical condition, like diabetes, or don’t take any supplements or medication. It all depends on your health status.

  • Are 40 day fasts possible?

40-day fasts might be possible but very extreme, with only a few people able to reach this time. This is because the body is at risk of malnutritionand kidney failure. It is generally not recommended to do prolonged fasts. Preparing for 40-day fasts requires time and must be done only under medical supervision.

The Bottom Line

While water fasting can lead to rapid weight loss, you should be aware of the potential risks. Consult your doctor before attempting a water fast, especially if you have any underlying health conditions. Medications taken with food may also be impacted by fasting, so discuss any concerns with your doctor to avoid side effects like nausea or electrolyte imbalance. If done under proper guidance, water fasting may offer benefits like weight management, improved immune function, and better blood sugar control.


This article is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional advice or help and should not be relied on to make decisions of any kind. Any action you take upon the information presented in this article is strictly at your own risk and responsibility!


  1. A periodic diet that mimics fasting promotes multi-system regeneration, enhanced cognitive performance and healthspan  (2015,
  2. An overview of autophagy: Mechanism, regulation and research progress (2021,
  3. Academy of Nutrition and Dietetics (n.d.,
  4. Autophagy, Aging, and Longevity (2019,
  5. Calorie restriction and fasting diets: What do we know? (2018,
  6. Complete and Voluntary Starvation of 50 days (2016,
  7. Efficacy and safety of prolonged water fasting: a narrative review of human trials (2023,
  8. Impact of prolonged fasting on insulin secretion, insulin action, and hepatic versus whole body insulin secretion disposition indices in healthy young males (2021,
  9. Intermittent Fasting: A Heart Healthy Dietary Pattern? (2020,
  10. Is Water-Only Fasting Safe? (2021,
  11. Orthostatic Hypotension (2023,
  12. Refeeding Syndrome (2022,
  13. The 7-Day Water Fast Guide: Benefits, Dangers, And Everything Else You Should Know (2024,
  14. The Effects of Prolonged Water-Only Fasting and Refeeding on Markers of Cardiometabolic Risk (2022,
  15. Water Fasting: Benefits and Dangers (2022,
  16. What Is Water Fasting And Should You Try It? (2023,
  17. What Is Water Fasting? Benefits, Risks And More (2024,
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