24-Hour Water Fast: Transform Your Health in a Day

Fasting for weight loss and religious purposes has been an age-old practice.

Many diets, such as the keto and Mediterranean, define what you can and cannot eat. However, diets such as intermittent fasting focus on the time of eating and fasting.

Water fast, on the other hand, is a fasting method where you cannot eat food or drink any caloric beverage for 24 hours. As the name suggests, you can only drink water during this fast.

While the availability of many fasting options can be a boon, it can be equally overwhelming, especially for those new to fasting.

As a health enthusiast, I can tell you that my journey of finding peace with a certain fasting method wasn’t easy. Finding the best diet for my body and mind took time, patience, understanding, and dedication.

As a beginner, I started with the 16:8 intermittent fasting. As my body found it slightly difficult to go without food for 16 hours at once, I stepped down to the 12:12 hour IF for a couple of months before progressing to the 14:10 IF pattern and eventually stabilizing at 16:8 IF.

Are you wondering why I am sharing my experience with you?

After successfully practicing 16:8 IF for a few months, I wanted to push myself for a 24-hour water fast. As my body was already used to fasting 16 hours a day, going without food for 24 hours didn’t seem difficult.

But it was only by doing this fast that I realized its benefits, and so I wanted to delve into the nuances of water fasting and share it with you.

The 24-hour water fast is similar to the 24-hour intermittent fasting, as you must forgo food and caloric beverages for a full day.

One word of caution to my readers: if you plan to undertake a water fast for 24 hours, please weigh its pros and cons. Also, such fasts may not be for everyone and should not be practiced frequently or for prolonged periods without the appropriate guidance.

Check out our detailed guide on how often you should fast for an informed approach to your weight loss goals.

This article is aimed at helping you understand what a 24-hour water fast is all about and how it can benefit your fitness goals. We will discuss some key highlights like what a 24-hour water fast is, how to prepare for it, and the advantages of this fast.

What is a 24-Hour Water Fast?

As you can derive from the name, 24-hour water fast is a fasting method that allows you to drink only plain water during the fasting period. This means you will be abstaining from food and all forms of caloric beverages for 24 hours, i.e., one full day.

Water fasting (WF) typically ranges from 24 to 72 hours. It is recommended to do WF in stages. For those attempting a water fast for the first time, it is advisable to start with intermittent fasting. Begin with a shorter fasting window, like 12 hours, before embarking on a 24-hour water fast.

Like intermittent fasting, during a 24-hour water fast, you will restrict calorie intake for the chosen fasting period, which, in this case, is 24 hours. Keeping yourself hydrated through the fasting period is an essential aspect of the 24-hour WF.

Tips to Prepare for a Water Fast

Commencing a fast with adequate preparation enables more informed and effective decision-making than beginning it on an impulse. That’s because gearing up for a fast allows your body the time and space to adjust to a new eating and fasting routine than what you follow on regular non-fasting days.

While a one-day water fast may appear straightforward as you simply have to abstain from any caloric intake for 24 hours. Prepping mentally and physically is essential to maximize the advantages of fasting.

Consider the following factors before and after your 24-hour water fast to enhance the overall effectiveness of the process:

Practice Shorter Fasts

As discussed above, it would be best to consider shorter fasting durations before commencing a full-day water fast. So, you can start with the 12/12 IF or the 16/8 IF and move to the warrior diet (20/4 IF), where you fast for 20 hours.

This will help you rehearse for the 24-hour fast, enabling smoother adjustment of your body and mind to an extended fasting period.

Consult a Health Expert

A water fast may have several benefits, like weight loss and improved metabolic health. (1)

But it may not be necessarily safe for everyone. If you have underlying medical conditions, water fasts for prolonged periods could cause more damage than good to your body.

Speaking to a health professional to discuss any pre-existing medical condition can minimize long-term risks associated with fasting. You can also discuss less extreme alternatives to weight management.

Keep Yourself Hydrated

A 24-water fast involves surviving on water for the duration of the fast. However, you must ensure you are well-hydrated throughout the day. Drinking water at regular intervals is the best way to prevent dehydration.

Although the majority opt for only water during the one-day fast, others may consume unsweetened, calorie-free tea or coffee throughout the fasting period. Although including a non-caloric beverage in your fasting window is up to your discretion, sticking to plain water for 24 hours has its benefits.

You can add non-caloric electrolytes to your fasting period to prevent dehydration. As you water fast, the body can’t source water from food or other fluids consumed during non-fasting periods.

Hence, you can consider replenishing your body with non-caloric electrolyte supplements.

Break Your Fast with Mindful Eating

A 24-hour water fast could induce cravings, with your mind wanting to binge eat upon breaking the fast. Yet, consuming high-carb, junk food or large meals immediately after fasting can be tough on your digestive system and may even counteract the benefits of the fast.

While fasting, your body’s digestive mechanism enters a resting and healing mode. When you eat mindlessly after a fast, the food takes longer to digest. Hence, you must be gentle on your digestive system after a fast, allowing it to gradually return to its regular action.

Processed and refined foods have very low nutritional value, can be difficult to digest, and irritate your gut microbiome. (2)

Instead, you can include fiber-rich foods in your diet. Eating simple and easily digestible food and not doubling down on meals before or after a fast is a better approach to fasting.

Like alcohol, sugar-rich or processed items can be difficult to digest upon breaking a fast, compromising the overall benefits of fasting. Studies reveal that high-protein diets before a 24-hour food and water fast can lead to discomfort and side effects. (3)

Active Lifestyle

Fasting benefits are not restricted to your diet habits alone; your overall lifestyle influences them. Exercise regularly, as it can boost your overall stamina and fitness. On your 24-hour water-only fasting day, you can perform low-intensity exercises such as walking, yoga, or other indoor exercises.

Benefits of a 24-Hour Water-Only Fast

As a periodic fast, a water fast akin to IF can benefit your health in various ways. However, longer water fasts may have different health impacts than shorter ones. For instance, maintaining long-term caloric restrictions may not be feasible as it may lead to nutritional deficiency.

Hence, 16:8 intermittent fasting or similar shorter fasts can be better alternatives. A study indicates the benefits of intermittent fasting are similar to those of caloric restriction. (4)

Here are some ways a 24-hour water fast can benefit your fitness goals:

1. Supports Your Weight Loss Goals

Fasting for 24 hours can help deplete your body’s glycogen stores. Glycogen is a form of glucose primarily stored in your liver and muscles. It is the primary energy source for the day-to-day functioning.

Only after your body uses up the stored glycogen levels will it begin burning fat to fuel itself. Although longer fasting periods can be relatively more effective in kickstarting ketosis, studies show that engaging in 24-hour fasts can be beneficial in managing body weight. It allows your body to switch to a fat-burning mode. (5)

2. Improve Metabolic Health and Lipid Levels

Studies reveal that fasting can improve insulin sensitivity and metabolic health. (6)

The same study also indicated that fasting can significantly lower blood lipid levels due to an improvement in the breakdown of triglycerides and oxidation of fat. This occurs after fasting for a duration of 18 to 24 hours.

3. Enhances Autophagy and Cellular Health

Autophagy is a process where your body discards damaged cells and replaces the dead cells with new cells. Studies indicate that a water fast or a calorie restriction diet can promote the natural process of autophagy. (7, 8)

Enhanced autophagy may aid in lowering risks associated with several chronic diseases, slow down aging, and support longevity. (9)

Frequently Asked Questions

Is a 24-hour water fast safe and effective for weight loss?

Yes, 24-hour water fast where you don’t consume any food or caloric beverages can be effective for weight loss, provided you ensure a healthy pre and post-fast diet, exercise regularly, and manage your stress levels.

However, you must evaluate the health risks, especially if you are new to fasting or have any pre-existing health condition. A 24-hour fast, like alternate-day fasting, may not be detrimental to a healthy human being. However,  prolonged water fasts can cause significant loss of sodium or potassium. Hence, as a safe and effective weight loss plan, you can also try intermittent fasting. (10)

Can I drink beverages other than water during a 24-hour water fast?

It is recommended to drink only water during a water fast. Drinking plenty of water at regular intervals through the fasting period will keep you hydrated. You can include non-caloric electrolytes in the fasting period to prevent dehydration. However, caloric beverages are a no-no as they can break your fast.

How should I break my 24-hour water fast?

Although there is no hard and fast rule to follow when breaking your 24-hour water fast, eating light and easily digestible food is the best way to break your fast.

Begin with fruits or boiled vegetables to provide your body with healthy sources of fiber. Spicy, refined, and processed foods and large meals are not advised as they can hinder the digestive process, which has been in a state of rest during the fasting period.

Summing Up

Fasting for a day with only water is generally safe and can be effective in several ways. Done the right way, it can be a favorable method for achieving weight loss goals.

I would suggest you begin with short intermittent fasting methods. To begin with, practice 12 or 16 hours of fasting, as it will help your body prepare and adjust for longer fasting durations.

Moreover, ensure you are in good medical condition and mentally ready to undergo a 24-hour water fast.

If you are unsure, consider consulting a doctor for guidance. Ensure that you consume essential nutrients in appropriate proportions before and after the fasting periods. Engage in light exercises and consider supplementing with non-caloric electrolyte supplements if necessary. Also, don’t forget to get adequate rest; it is equally important for healing and optimal body functioning.

References

1. Ezpeleta, M., Cienfuegos, S., Lin, S., Pavlou, V., Gabel, K., & Varady, K. A. (2023, June 27). Efficacy and safety of prolonged water fasting: a narrative review of human trials. Nutrition Reviews.
2. Zhang, P. (2022) ‘Influence of Foods and Nutrition on the Gut Microbiome and Implications for Intestinal Health’, International Journal of Molecular Sciences, 23(17), p. 9588. ‌
3.   The dietary composition of pre-fast meals and its effect on 24-hour food and water fasting. (2001, September 1). PubMed. https://pubmed.ncbi.nlm.nih.gov/11574981/
4. Song, D. K., & Kim, Y. W. (2023, January 31). Beneficial effects of intermittent fasting: a narrative review. Journal of Yeungnam Medical Science.
5. Sanvictores, T. (2023, July 24). Physiology, Fasting. StatPearls – NCBI Bookshelf.
6. Wang, Y., & Wu, R. (2022, January 5). The Effect of Fasting on Human Metabolism and Psychological Health. Disease Markers.
7.   Alirezaei, M. et al. (2010) Short-term fasting induces profound neuronal autophagy,   Autophagy. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3106288/ (Accessed: 05 January 2024).
8. Shabkhizan, R., Haiaty, S., Moslehian, M. S., Bazmani, A., Sadeghsoltani, F., Bagheri, H. S., Rahbarghazi, R., & Sakhinia, E. (2023, September 1). The Beneficial and Adverse Effects of Autophagic Response to Caloric Restriction and Fasting. Advances in Nutrition.
9. Bagherniya, M., Butler, A. E., Barreto, G. E., & Sahebkar, A. (2018, November 1). The effect of fasting or calorie restriction on autophagy induction: A review of the literature. Ageing Research Reviews.
10. Ogłodek, E., & Pilis, W. (2021, January 1). Is Water-Only Fasting Safe? Global Advances in Health and Medicine.

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