Written by Garett Reid | NSCA, CSCS, CISSN, M.S.E.S.S
Fact checked by Andrew Lenau, ISSA CPT & Sports Nutritionist
FACT CHECKED
Those who partake in fasting often swear by its benefits, which range from weight loss to reducing inflammation to building immunity.
And while there is still much left to uncover about fasting, studies have already shown there are some real benefits to it. Now, as we know, as soon as research begins pointing out a practice that yields real health benefits, like fasting, it begins garnering even more interest, particularly in the fitness community.
One such method of fasting that's begun popping up more is dry fasting. But before you jump on the dry fasting bandwagon, it's important to learn exactly what it is and how it compares to other fasting methods.
We're about to get into all of that (and more) in this article, which will cover:
- What is a dry fast?
- Overview of different styles of fasting
- Dry fasting benefits and downsides
- Dry fasting vs. water fasting
- How to follow dry fasting
If you're wondering: "What's a dry fast?", you've come to the right place! You'll know everything you need to by the end of this article.
What Is Dry Fasting?
A dry fast is the absolute fasting of both food and liquids, including water. When talking about the dry fasting meaning, you have no food, water, or any other form of nutritional intake, even including things like gum and mints.
When examining the typical protocol for dry and water fasting, the obvious difference is that with dry fasting, you're fasting without water. This is an important distinction, as not drinking water can increase your risk of dehydration and even heat exhaustion.
What Is Fasting?
As mentioned above, fasting is simply the practice of refraining from eating food. Initially, fasting came from various religious systems, including things such as the practice of Lent in the Christian faith or Ramadan fasting in Islam. Over time, this has evolved into a general health practice.
There are various types of fasting, but the main idea behind them all is no eating, and sometimes, no eating or no drinking. You rarely, if ever, see someone eat but not drink.
The duration of fasting depends on several factors. In reality, every time you stop eating, you're technically fasting until your next meal. If you think about it, everyone fasts from the moment they stop eating at night until they eat breakfast in the morning. That's why breakfast is called "break" "fast."
That said, when someone is purposely fasting, most intermittent fasting schedules usually last at least 16 hours. Some people will go a week for the longest duration, but the "average" prolonged fasting is around 24-36 hours.
This can be done in the form of periodic fasting, which is when someone fasts at various times throughout the year. It may also be performed on a consistent schedule. We'll get into this more below.
Scientific Studies On Fasting
As far as studies on the health benefits of fasting go, most have been done looking at Ramadan fasting. Research has expanded to other sectors, but surprisingly, the total number of studies is still relatively small.
And when you're trying to find research on actual performance benefits, the number is even smaller. Most of the studies look at the effects on mental health benefits, well-being, and various other physiological effects.
Other Fasting Types & Schedules
There are multiple fasting types and schedules, including those you can follow while adhering to dry fasting. There are even recommendations on best intermittent fasting practices for women.
Here's a look at the different fasting types and time frames.
Water Fasting:
Water fasting is the more common form of prolonged fasting in which a person abstains from eating food but still drinks water. To be clear, true water fasting only allows drinking water, requiring you to refrain from all other liquid forms regardless of whether they have calories.
Intermittent Fasting:
Intermittent fasting is the most common type of fasting that an individual follows on a long-term basis. While it's not technically a diet, as you can eat what you want, it has that same level of control over a person's life.
When following intermittent fasting, a person will follow it for a prolonged period of time, generally, at least 3 months, while some always follow the diet apart from special circumstances.
Intermittent fasting involves dividing your day into a shorter feeding window and a longer fasting window. The possible intermittent fasting protocols are:
- 16:8: This is the most common intermittent fasting window used by the fitness community.
- 18:6: This involves 18 hours of fasting and a 6-hour feeding window.
- 20:4: This is a 20-hour fasting window and a 4-hour feeding window.
- 23:1 (One meal a day): A 23:1 protocol, also known as one meal a day (OMAD), is the most extreme form of intermittent fasting practiced daily.
Alternate Day Fasting Or 5/2:
Alternate-day fasting is exactly what it sounds like. You refrain from eating every other day. This is a less common form of 24+ hour fasting. The more popular form of 24+ hour fasting is a 5/2 protocol, which requires you to fast for 2 days and eat normally for 5 days.
Liquid Fasting:
A liquid fast is a form of fasting in which you refrain from solid food. However, anything liquid is on the table, including water, coffee, smoothies, protein shakes, and fruit juice.
These are actually good introductions into the water fast. While you're still consuming calories, the liquid will not be near as satisfying as food, allowing you to adjust to the initial sensations of persistent hunger.
Health Benefits Of Dry Fasting
Here is a look at some research-backed dry fasting benefits.
1. Lowers Blood Sugar:
Along with increased insulin sensitivity, fasting has long been known to help lower blood sugar levels, which makes sense as you're not eating sugar for a prolonged period of time.
One study looked at practitioners of the Bahá’í faith who did a dry fast during the day for 19 days¹. At the end of their study, they had significantly lower blood sugar.
2. Builds The Body's Immune System:
In 2020, a study examined the various effects of a dry fast on our physiological and metabolic systems². Ten participants followed a dry fast for 5 consecutive days and then 3 days of a diet, which slowly increased in calories each day. They found numerous health improvements, including the fact this regime had an immune-stimulating effect.
In 2021, another review that examined the possible use of a dry fast against Covid noted the positive effects of consistent fasting on the immune system³.
3. Decreases Inflammation Levels:
Chronic inflammation causes a litany of health complications. And, fortunately, research has found that dry fasting decreases inflammation levels.
A 2022 study found that people participating in a 4-week daytime dry fast experienced several beneficial metabolic syndrome changes⁴. After the study, these participants reduced inflammation levels and exhibited anti-atherosclerotic and anti-tumorigenic properties.
Worth noting, similar findings were found with water fasting during Ramadan fasting⁵.
4. Encourages Cell Regeneration:
Prolonged fasting has been found to be effective at encouraging cell regeneration. A study from 2014 examined the effects that a longer fasting window of 48 hours had on lab mice⁶. They discovered that prolonged fasting had numerous positive effects on cell regeneration.
5. Combats Cancer Treatment Side Effects:
Another great dry fasts benefits: It can combat side effects of cancer treatment.
Interestingly, similar findings involving cell regeneration were found in another 2014 study, suggesting that prolonged fasting could be beneficial in fighting against the detrimental effects of chemotherapy⁷. This same sentiment was also echoed in the above study⁶.
Does Dry Fasting Help With Weight Loss?
Assuming you don't overeat on your feeding days, yes, you're going to lose weight when fasting, simply because you're not eating.
However, if you're interested in dry fasting for weight loss, there are much safer and more effective methods. For instance, water fasting is a better option.
While weight loss will occur, it should be looked at as a secondary benefit. There is no reason to not drink water if you're only interested in cutting calories. If you're doing it to shed pounds, consider following a cutting workout and diet plan or counting macros. If you want to try fasting and lose weight, a 16:8 intermittent fasting plan is ideal.
At the end of the day, cutting calories will drive your weight loss, not forgoing water.
And remember, your food choices still matter. Sometimes there is an idea that if you practice fasting, you can eat whatever you want in the feeding window. This is not true.
If you binge eat junk food during your feeding window, you're going to set yourself up for eating disorders as well as possible other health complications.
Cons of Dry Fasting
While there are some health benefits to dry fasting, there is also the risk of health complications, leading to the question: "Is dry fasting safe?" Unfortunately, some of these cons are life-threatening and should be taken very seriously. We may still have a lot to learn about the body, but we do know one thing: You need water to survive.
Here are some of the top concerns you need to watch out for.
1. Dehydration:
The most obvious risk of fasting dry is dehydration. Even if you lay in bed all day, you still expel water through respiration, gas, and urine.
Now imagine if you don't lay in bed all day, but rather go on to fulfill a day's worth of activities, including your workout split. You will become dehydrated.
2. Fainting And Heat Stroke:
We sometimes dismiss the importance of our water intake and act as if its only job is to keep us hydrated. However, being hydrated affects numerous other physiological processes. One of those is the regulation of your internal body temperature.
Water helps the body dissipate heat and transfer energy (heat). Due to this, it plays a pivotal role in keeping our internal temperature at an even 98.6 degrees.
When you don't drink for a prolonged duration, you will become dehydrated, which significantly increases your chance of a heat-related illness, such as heat stroke.
While the main factor in developing heat stroke is a high external temperature, being depleted of water only decreases your body's ability to fight this.
Other possibilities are heat exhaustion and fainting. This is yet another reason we believe only those experienced with fasting should take part in a dry fast. And if you're going to try it, start with shorter time periods and remain in cool places. Make sure you don't participate in heat therapy when dry fasting.
3. Extreme Discomfort:
This may come as a surprise, but fasting is not meant to be an uncomfortable experience. While you may get urges to eat, a long duration of strong, persistent hunger is probably a sign you're starting too extreme.
Perseverance and improving mental toughness are a part of fasting. However, if all you can think about is the discomfort and food, you are either not mentally prepared, or your body isn't ready.
4. May Lead to an Eating Disorder:
Anyone who wants to try a dry fast needs a healthy relationship with food. By this, we mean you don't binge eat and you can fight cravings.
Your food choices should be relatively healthy, and ideally, you should have a decent body mass index. While you don't need to be shredded, a higher body weight can increase your chances of dehydration and heat illness.
If you have a higher body weight, you're much better off first following a strength training plan, adding in some LISS cardio, and making healthy food choices, like these high protein low fat foods. Once you have those things nailed down, you can start to consider dry fasting.
Remember, if you try to use a dry fast to correct your calorie intake or for weight loss, you can end up in a bad spot. When you're done fasting, your bad habits can multiply.
The takeaway here is to not use a dry fast as a treatment for being overweight. Also, make sure you're healthy before dry fasting. If you have any concerns or a history of eating disorders, check with a doctor first.
How To Dry Fast
If you are interested in trying a dry fast, you can ease into it by following these recommendations.
1. Start with a 16:8 Schedule.
Start with some basic intermittent fasting using a 16:8 feeding schedule. During your eating window, drink and eat like you normally do. After a couple of weeks, assess how you feel.
If you feel good, extend your fasting window to 18 or 20 hours. It's also important to note that following a fasting schedule like this one, compared to fasting for days at a time, is much better for preserving and building muscle.
2. Follow a Juice Cleanse.
When you feel ready, follow a juice fast for a week. During this time, you can drink liquids anytime you like. But to be clear, you can only drink liquids. When you feel ready, follow some intermittent fasting protocols, but only drink liquids during your feeding. It can take anywhere from 2-4 weeks to comfortably adjust to this.
3. Try a one-day water fast.
Plan a day to follow your first 24+ hour water fast when ready. Your first one should be from 12pm to 12am or something similar.
4. Don't eat for an entire day.
When ready, go an entire day not eating. This goal here is you wake up and then don't eat until you wake up the next day.
After this becomes relatively easy to do, you can then jump into dry fasting. Again, first use the intermittent dry fasting protocol and assess how you feel. As your body adapts, you can lengthen your fasting window.
Should You Dry Fast?
This is a personal choice. After looking at all of the evidence, we're not convinced that dry fasting provides any benefits that can't be seen with other forms of fasting.
At the same time, there are a lot of anecdotal reports that talk about an improved sense of well-being and spirituality. If that is what you're after and you fall into the healthy adults demographic, it may be for you.
It's also important to consider that many of the health benefits of dry fasting, such as increased insulin sensitivity and decreased cravings, are also seen in those who partake in water fasting and even intermittent fasting.
It's important to understand why are you fasting in the first place. If weight loss or improved sleep is your goal, cut down on the amount of time you eat during the day.
For example, one study found the average adult has a feeding window of 15 hours8. By reducing the window to 10-11 hours, participants improved sleep and body composition.
This leaves the question: Are the increased risks of refraining from water worth any benefits that aren't seen in other forms of fasting?
We don't think so, at least not with the current state of scientific research. But there are enough positive results that we also don't think it's completely useless either.
Our final takeaway: Before we recommend it to our readers, we want more in-depth studies to be done on it.
Dry Fasting FAQs
Left with some lingering dry fasting FAQs? We're about to answer them!
1. How effective is dry fasting?
It's effective to some extent, depending on your goals. Some dry fasting benefits include improved immune function, decreased inflammation levels, and improved blood sugar levels and insulin sensitivity.
2. How long can you do dry fasting?
The longest time advanced fasters should do a dry fast is generally around 3-4 days. It also shouldn't be done often. Beginners and intermediate fasters should stick to 24 hours.
3. Can you shower during a dry fast?
That depends. Do you want to do a hard, dry fast, or a soft dry fast? A hard, dry fast has you refrain from touching the water. This includes brushing your teeth and taking a shower. A soft dry fast simply has you stop your water intake. While you can't drink water, you can still shower, brush your teeth, and wash your face.
Interested in learning more about fasting? Be sure to check out this article offering first-hand perspective on what it's like to follow a 3-day fast, along with information on how to do it, what to expect, benefits, and tips.
Considering working out while fasting? Read our article on fasted cardio first!
References:
- Mähler, A., Jahn, C., Klug, L., Klatte, C., Michalsen, A., Koppold-Liebscher, D., & Boschmann, M. (2021). Metabolic Response to Daytime Dry Fasting in Bahá'í Volunteers-Results of a Preliminary Study. Nutrients, 14(1), 148. https://doi.org/10.3390/nu14010148
- Papagiannopoulos-Vatopaidinos, I. E., Papagiannopoulou, M., & Sideris, V. (2020). Dry Fasting Physiology: Responses to Hypovolemia and Hypertonicity. Physiologie des Trockenfastens: Reaktionen zu Hypovolämie und Hypertonizität. Complementary medicine research, 27(4), 242–251. https://doi.org/10.1159/000505201
- Bhatti, S. I., & Mindikoglu, A. L. (2022). The impact of dawn to sunset fasting on immune system and its clinical significance in COVID-19 pandemic. Metabolism open, 13, 100162. https://doi.org/10.1016/j.metop.2021.100162
- Mindikoglu, A. L., Park, J., Opekun, A. R., Abdulsada, M. M., Wilhelm, Z. R., Jalal, P. K., Devaraj, S., & Jung, S. Y. (2022). Dawn-to-dusk dry fasting induces anti-atherosclerotic, anti-inflammatory, and anti-tumorigenic proteome in peripheral blood mononuclear cells in subjects with metabolic syndrome. Metabolism open, 16, 100214. https://doi.org/10.1016/j.metop.2022.100214
- Cherif, A., Roelands, B., Meeusen, R., & Chamari, K. (2016). Effects of Intermittent Fasting, Caloric Restriction, and Ramadan Intermittent Fasting on Cognitive Performance at Rest and During Exercise in Adults. Sports medicine (Auckland, N.Z.), 46(1), 35–47. https://doi.org/10.1007/s40279-015-0408-6
- Cheng, C. W., Adams, G. B., Perin, L., Wei, M., Zhou, X., Lam, B. S., Da Sacco, S., Mirisola, M., Quinn, D. I., Dorff, T. B., Kopchick, J. J., & Longo, V. D. (2014). Prolonged fasting reduces IGF-1/PKA to promote hematopoietic-stem-cell-based regeneration and reverse immunosuppression. Cell stem cell, 14(6), 810–823. https://doi.org/10.1016/j.stem.2014.04.014
- Hine, C., & Mitchell, J. R. (2014). Saying no to drugs: fasting protects hematopoietic stem cells from chemotherapy and aging. Cell stem cell, 14(6), 704–705. https://doi.org/10.1016/j.stem.2014.05.016
- Gill, S., & Panda, S. (2015). A Smartphone App Reveals Erratic Diurnal Eating Patterns in Humans that Can Be Modulated for Health Benefits. Cell metabolism, 22(5), 789–798. https://doi.org/10.1016/j.cmet.2015.09.005
Garett Reid
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