Water Fasting: Understanding the Risks and Benefits

🤝 Our content is written by humans, not AI robots. Learn More

Water fasting along with other forms of fasting have gained popularity in recent years as a method claimed to help individuals with body detoxification, weight loss, and improved well-being.

Even though some results from water fasting have been praised in the past, it is essential to recognize that this extreme form of fasting comes with more significant risk than benefits and should not be underestimated.

In this article, we will discuss water fasting and dive into detail on the risks and potential benefits of this fad diet.

📌 Key Takeaways

  • Water fasting restricts everything including all foods and drinks except for water.
  • Water fasting may result in quick and fast weight loss but it can have serious health consequences
  • Quick and fast results are usually too good to be true and often result in weight re-gain.
  • The best way to lose weight is to choose a sustainable healthy lifestyle with balanced nutrition, activity and sleep.

🤔 What is Water Fasting?

Water fasting is essentially a dietary restriction that restricts everything except for water. It is often times promoted as a fast and easy way to lose weight.

Typically water fasting lasts from 24-72 hours. However, it can vary in length. In general, it is not recommended to do a fast for long periods of time as this can cause adverse events.

While water fasting is more of a fad these days for losing weight, historically, it has been used for spiritual purposes for thousands of years.

Other reasons why people may water fast include “detoxification” or for its other reported health benefits.

Related: Everything to Know About Detox Water

Water fasting concept

🚰 How Do You Water Fast?

In terms of “how you water fast” there is not enough research on the diet to even establish safety recommendations. Generally, it is recommended to discuss any types of fasting with your health care provider beforehand because it can be dangerous for some individuals.

Additionally, because a water fast is so restrictive it is not recommended to do it without medical supervision.

Who Should Avoid Water Fasting?

In general, water fasting for prolonged periods of time is not considered to be safe. However, particularly for those that have diabetes, gout, or an eating disorder should refrain from engaging in water fasts altogether.

Additionally, women who are pregnant, older adults, and children are not recommended to water fast.

⚠️ Potential Health Risks of Water Fasting

Generally if you are doing a short water fast for 24 hours there are little to no harmful effects. However, if you extend your fast beyond 24 hours, there are many health risks.

For example, a recent study published health benefits associated with prolonged water fasting followed by a post phase fast diet.

Even though this study suggested health benefits associated with this diet, it is important to note that 13 out of 46 participants also withdrew due to an adverse event associated with the fasting period.

Some of the adverse events included panic attacks, headaches, fatigue, anxiety, vomiting, cramping and heart palpitations. It is important to recognize that this is a significant amount of individuals that had adverse events when trying to complete a prolonged water fast.

Muscle Loss

Water fasting, or any prolonged period of fasting, can lead to significant muscle mass loss. This is because when the body lacks sufficient energy, it begins to break down muscle mass to meet its energy demands.

This happens particularly when calories are significantly reduced. With all weight loss, some muscle mass loss is bound to occur. But, compared to slow and steady weight loss, prolonged fasting generally results in greater muscle mass loss.

Even though proponents of water fasting may claim that it burns fat effectively, it does come at a cost of muscle wasting which overall impacts your physical strength and metabolic rate in the long run.

Electrolyte Imbalances

Fasting with water alone can disrupt the body’s delicate balance of electrolytes, including sodium, potassium, calcium, and magnesium.

Electrolytes play a crucial role in maintaining proper cellular function, nerve transmission, and muscle contractions.

Severe imbalances can result in heart rhythm abnormalities, dizziness, weakness, and even life-threatening conditions like arrhythmias.

Feeling sick after drinking water

Adverse Effects on Mental Health

Fasting, especially for prolonged periods, can have a profound impact on mental health. Some individuals may experience increased irritability, mood swings, anxiety, and depression during water fasting.

The strict restrictions and mental focus on food can also trigger or exacerbate disordered eating behaviors.

Over restrictive diets like water fasting may also trigger eating disorders. Fasting for prolonged periods of time teaches you that food is a “bad” thing that contributes to weight gain. It may also lead to binge eating when restricting calories so significantly.

However, in reality it is meant to be something that nourishes our body and helps our human bodies do amazing things like climb to the top of Mt. Everest or have a baby.

Impact on Blood Sugar Levels

Water fasting can lead to fluctuations in blood sugar levels, which can be particularly concerning for individuals with diabetes or those prone to hypoglycemia.

Without a steady supply of glucose from food, blood sugar levels may drop dramatically, leading to weakness, confusion, and in severe cases, loss of consciousness.

Increased Risk of Orthostatic Hypotension

Dehydration can occur with water fasting which can lead to orthostatic hypotension. Orthostatic hypotension is a sudden drop in blood pressure that occurs when standing up from a seated or lying position.

Water fasting can increase the risk of orthostatic hypotension, leading to dizziness, fainting, and falls. It may also increase uric acid production which can exacerbate gout.

Water fasting can cause blood pressure drop

🩺 Potential Health Benefits

These days, on social media, you can find many “experts” that promote the health benefits of a water fast. Often times the goal is weight loss or other health benefits such as reducing the risk of chronic diseases like cancer, diabetes and coronary artery disease.

However, the truth is that there is not a ton of human research on water fasting to support these health claims.

Promotes Autophagy

One of the benefits that is water fasting is thought to have is promoting autophagy. Autophagy is a process that gets rid of all the old parts of your cells, breaks them down and recycles them.

There are several animal studies that suggest water fasting promotes autophagy. This is important because there are also studies that suggest autophagy can reduce risk of cancer, alzheimer’s disease, and cardiovascular disease.

While this is promising, there is not enough studies on the effects of water fasting in humans so more research is necessary to know if there are the same effects in humans.

Reduce Blood Pressure

There are are some studies that prolonged water fasts that are medically supervised result in lowering blood pressure.

In the study mentioned earlier in this article, aside from some adverse events, the study also demonstrated that the water fast followed by post phase diet reduced both systolic and diastolic blood pressure, body weight, BMI, abdominal circumference, LDL cholesterol and inflammation.

A separate review also demonstrated that water fasting may help reduce blood pressure in those with cardiovascular disease. This is particularly clinically relevant since high blood pressure puts individuals at higher risk for a cardiac event.

Improve Insulin Sensitivity

There are also studies that suggest water fasting can improve leptin and insulin sensitivity. Why is this important?

Well, insulin and leptin are both hormones in the body that can impact your metabolism.

Insulin is a hormone that is released from your pancreas in response to a meal. From there, it helps bring the sugar in your bloodstream into your cells to be used for energy.

If the body doesn’t recognize this signal, this is called “insulin resistance” and can lead to elevated blood sugars and diabetes mellitus.

Leptin is a hormone that is released to let you know you are full after a meal. Some research has shown that water fasting improves both insulin and leptin sensitivity.

Checking insulin level

Lower Risk of Chronic Disease

As mentioned earlier, because water fasting has shown to induce autophagy in animal studies, there is some evidence to suggest that it may help reduce risk for chronic diseases that autophagy helps combat like alzheimer’s disease, cancers, and heart disease.

There are some studies that have demonstrated that fasting in general may help reduce the growth of cancer cells.

To further emphasize, there is not enough human research to adequately substantiate some of the reported health benefits of water fasting.

🔎 Sustainability

As a dietitian, one of the many problems with fad diets is that they promise fast weight loss but are not sustainable. If you have any health conditions or are overweight, you should talk to your health care provider or a Registered Dietitian Nutritionist (RDN) for their expertise.

Particularly, if you are looking for nutrition expertise an RDN is the person to consult with. News flash – they aren’t going to recommend a water fast for weight loss.

Why Isn’t it Sustainable?

Water fasting may help you lose a few fast pounds, however you are likely to regain the weight lost if you do not change your daily habits and create a better lifestyle.

This means, following a general healthy diet (eating less sugar and high fat foods, eating more veggies, fruits and whole gains!), increasing activity, and getting better sleep.

All of these things can help you to achieve your weight loss goals in a more sustainable fashion, if you make small and realistic changes.

Water fasting might show fast results but will not give you that long term result you’re looking for.

Water and eating healthy

👩‍⚕️ Is There a Healthier Way to Fast?

One of the more popular diets that is a less restrictive method of fasting includes intermittent fasting. While it still may not be sustainable for long periods of time, there is a lot of research to support its benefits.

Intermittent fasting is essentially fasting for varying windows of time(usually between 8-16 hours per day) and eating your meals during your non-fasting window.

For example, you could “water fast” for 8 hours of the day and the other hours you could eat your meals. Similar to all diets, it is important to consult with an RDN to see if intermittent fasting is right for you.

Related: Can you drink water during intermittent fasting?

📑 Conclusion

While water fasting may seem appealing as a quick fix for weight loss and detoxification, it is crucial to acknowledge the inherent dangers and risks associated with this extreme dietary practice.

Water fasting can put immense stress on the body and should not be taken lightly. Individuals with certain medical conditions, such as diabetes, heart problems, or eating disorders, should avoid water fasting altogether, as it can exacerbate their conditions.

Instead of resorting to extreme fasting methods, focusing on balanced and sustainable dietary habits, regular exercise, and seeking guidance from qualified healthcare professionals is a more realistic approach to achieving overall health and well-being.

Remember, everyone’s body is unique, and what works for one person may not work for another. Prioritizing safety and long-term health should always be the top priority when considering any dietary or lifestyle change.

It is also important to recognize that more research is needed in this area.

❔ Frequently Asked Questions

Can You Lose Weight By Water Fasting?

In general, you can lose weight from water fasting. However, when calories are restricted significantly in a short period of time, people are more likely to lose a larger portion of muscle mass than if they were to lose weight slow and progressively.

It is also important to consider that your results may not be long terms results and may just be quick fix rather than aiming to look at the your overall lifestyle and ways to lose the weight and keep it off.

How Long Do You Water Fast?

Water fasts typically last from 24-72 hours. However there are some who may do water fasts for prolonged periods of time. It is important to note that with a prolonged water fast, medical supervision is necessary due to the various risk factors of a prolonged fast.

How Much Weight Can You Lose With Water Fasting?

You can lose varying amounts of weight depending on how long a period you water fast for. However, as mentioned in the article above, since it is not sustainable and most people turn back to their normal eating habits, the weight is less likely to stay off.

Not only that, but it can also result in more muscle mass loss than traditional weight loss methods.

For a more long lasting approach to weight loss, try small sustainable changes to your routine like reducing sugar and increasing activity.

Is Water Fasting For 7 Days Good?

In general, fasting for long periods of time without medical supervision is not recommended. This is because it can result in adverse events as documented in some research studies such as anxiety, panic attacks, fatigue, vomiting and heart palpitations.

  • Roxanne Trotter
    MS, RDN

    Registered Dietitian Roxy, fueled by her love for food and wellness, tackles misinformation head-on. Her Master's in Human Nutrition and diverse experience (weight management, hospitals) equip her to translate complex health topics, especially those related to water quality. Through her own practice (Nutremedies LLC) and writing for Water Filter Guru, Roxy empowers readers with accurate, evidence-based information, helping them make informed choices for a healthier life, one sip at a time.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top