Water fasting has become the best health hack since sliced brown bread, with millions already following intermittent (water) fasting. But there’s an underdog ready to take down water fasting: dry fasting.
What’s the difference between dry fasting and water fasting?
Dry fasting means complete abstinence from any source of sustenance, no food or water. Wet fasting means abstinence from food. However, you can have certain liquids, such as black tea, green tea, coffee, and depending on the purpose of the fast, sometimes even bone broth is allowed.
Dry fasting vs. wet fasting
The biggest distinction between dry fasting and wet fasting is that liquids are not allowed in a dry fast, and liquids are allowed in a wet fast. Although both are beneficial for health, dry fasting, compared to wet fasting, gives you greater benefits; however, wet fasting can be less challenging and easier to practice.
Dry fasting is sometimes referred to as absolute fasting, although the term dry fasting is more widely used. Wet fasting is another name for water fasting, although water fasting is more widely used.
Water fasting has many benefits—it helps with weight loss, extends lifespan, fights cancer, and increases insulin sensitivity which helps with diabetes and a myriad of metabolic diseases. In the long run, regular water fasting keeps your body young and healthy.
However, a dry fast has a longer list of health benefits compared to a water fast. Dry fasting causes dehydration, which is stressful for your body, forcing your system to adapt and change its metabolic pathways to make its own water.
Both water fasting and dry fasting do share many of the same benefits. Dry fasting, however, is more efficient, gaining similar results one-third of the time. The extensive healing processes facilitated by cellular recycling mechanisms that occur within 1 day of dry fasting (quicker if you’re already in ketosis) usually only happen with prolonged water fast of 3–5 days. Dry fasting is water fasting on hyperdrive.
Is dry fasting better than water fasting?
Although dry fasting works faster, it doesn’t necessarily mean it’s better. The difference between dry fasting and water fasting is like taking the shortcut and taking the scenic route. Both get you there, but one takes you longer and is more enjoyable.
That doesn’t mean dry fasting is uncomfortable; in fact, many advanced faster say they prefer dry fasting to water fasting because they won’t feel hungry at all.
Whether dry fasting is better than water fasting depends on your health, aptitude, comfort level, and goal. If you’re advanced in your fasting practice and want quick health results, then dry fasting might be better. If you’re new to fasting, and your goal is to lose weight, then water fasting would be better.
Dry fasting vs. wet fasting – duration of fast
A dry fast can be 12 hours to 11 days, with intermittent dry fasting being most common—since over 1.7 billion Muslims dry fast every year for 11–22 hours during the holy month of Ramadan. There are multiple proven benefits from Ramadan dry fasting.
Dry fasting daily is recommended for most people, with 24 hours being the recommended duration for people. More advanced fasters can fast up to 3–5 days without supervision. Fast over 5 days usually requires some supervision, unless you are seasoned dry faster, and know what you’re doing.
Water fasting is usually 12–20 hours for intermittent fasting and 24–72 hours for prolonged fasting. The recommended duration is 72 hours (or 3 days) for the easiest, safest way to do a water fast to maximize benefits and minimize risks.
However, some people do medical water fast for 7–14 days, sometimes even for 30 days. The longest water fast ever done was for 318 days, under medical supervision. The patient was in excellent health, felt great during the entire duration of the fast, and lost significant weight.
You can practice both dry fasting and water fasting in combination with these fasting patterns.
- Intermittent Fasting (12:12, 14:10, 16:8, 18:6, 20:4, 22:2)
- OMAD (One Meal A Day)
- Once or twice weekly 24 hours fast
- Alternate day fasting (24 or 36 hours)
- A Weekly 24-hour fast
Dry fasting vs. wet fasting – preparation / exit
Water fasting and dry fasting differ a little bit in preparation before the fast and after. Although both do have their own set of dos and don’ts, it depends on the duration of time you’re doing the fast.
An intermittent dry fast of fewer than 20 hours doesn’t require too much thought, but prolonged dry fasting (24 hours and above) could have extensive preparation before a dry fast, something taking up to a month. Breaking the dry fast must also be handled carefully, even if it’s just a 24-36 hour dry fast; otherwise, you could undo a lot of the benefits. Breaking the fast if you’re prone to weight loss also must be handled with even more care.
Water fasting is relatively easier to handle in terms of entry and exit. You can do a 24–36 hour water fast every other day, and although you should follow refeeding protocol, it’s simpler.
Dry fasting vs. wet fasting – who shouldn’t do it?
These are some of the similarities and differences between who shouldn’t attempt dry fasting and water fasting. Pregnant and breastfeeding women should never fast, as they need the nutrition and water for their health and their child’s health. Children also constantly need food for proper growth.
Some people who can water fast can’t do a dry fast, which makes the decision simple. Similarly, some people who can’t water fast might dry fast—especially for shorter durations of time.
While other people must exercise caution and get medical advice, always speak to a medical professional if you’re on this list and want to attempt fasting.
Dry fasting: Who shouldn’t do it
- Pregnant Women
- Breastfeeding Women
- Children under 18
- People over 80 years old
- Injured, stressed, or weak people
- Taking medication that requires drinking water with pills (chronic conditions liked diabetes which makes you pee often)
- Anyone at the risk of dehydration: vomiting, diarrhea, in the sun often, in high temperatures, alcohol binge drinking, excessive exercising, long haul flights)
Water fasting: Who shouldn’t do it
- Pregnant Women
- Breastfeeding Women
- Children under 18
- People over 80 years old
- People with Medical Conditions—taking medication that can cause stomach issues
- Type 1 or Type 2 diabetes
- GERD (Gastroesophageal Reflux Disease)
- Underweight or Malnourished
Dry fasting vs. wet fasting – safety/ risks
The dangers and risks of dry fasting and water fasting differ in that dry fasting is a form of dehydration for your body, resulting in symptoms and risks of dehydration.
Risks of dry fasting
- Vertigo / Dimmed Vision
- Blackouts/ Fainting
- Nausea, Vomiting, Regurgitation
- Severe Dehydration
- Refeeding Syndrome
- Excess Weight Gain Refeeding
Go here for more on potential dangers, side effects, and symptoms of dry fasting.
Water fasting risks have more to do with nourishment, deficiencies, and medical issues aggravated by not having food.
Risks of water fasting:
- Blood pressure Changes (Vertigo/ Dimmed Vision/ Fainting)
- Worsen gout
- Worsen Diabetes
- Cause Food Disorders
- Refeeding syndrome
- Hyponatremia (excess salt loss)
Dry fasting vs. wet fasting – benefits
Assuming the best practices, both water fasting and dry fasting are incredible for their health benefits. A fast gives your body a break from digestion and forces it to spend all its time healing and repairing. The entire process of eating and assimilating food can take up to 80% of your body’s energy, which doesn’t leave much energy for healing and repair. Whenever you sleep and digestion stops, your body starts the repairing process—which is why you shouldn’t have a big meal before going to sleep!
The benefits of water fasting:
- Mental Clarity & Focus
- Weight/ Fat Loss
- Lowers Blood Sugar
- Treats & Prevents Diabetes
- Improves Blood Cholesterol
- Increases Energy
- Reverses Aging
- Improves Fat-Burning / Ketosis
- Decreases Inflammation
- Reduces Risk of Chronic Diseases
- Prevents Alzheimer’s
While water fasting gives your digestive system a break, the excess water also helps flush out toxins from your system, ridding it of poison and waste, cleansing the system.
Dry fasting enjoys more on the list of benefits because it’s a double whammy. Not only does your body get a break from food and digestion, but lack of water necessitates the creation of endogenous water, your own metabolic pure water.
This lack of water amplifies your body’s need to remove useless resources to get more water—including unhealthy, damaged, sick cells and pathogens. Dehydration during dry fasting also reduces inflammation because inflammation cannot exist without water.
The benefits of dry fasting:
- Promotes Weight Loss
- Increases Metabolism
- Promotes Lean Muscle Growth
- Induces Autophagy
- Promotes Stem Cell Regeneration
- Increases Life Expectancy
- Slows Down Aging
- Improves Skin
- Accelerates Wound Healing
- Lowers Cholesterol & Blood Pressure
- Prevents Coronary Heart Disease
- Prevents & Treats Diabetes
- Improves Liver Health
- Improves Kidney Health
- Enhances Cognitive Function
- Improves Bone Health
- Improves Infertility & Gynaecological Diseases
- Prevents & Fights Cancer
- Supports Chemotherapy Treatment
- Improves Digestive System
- Improves Immune System
- Reduces Stress
- Increases Energy Level
- Induces Healthy Eating Habits
See more on dry fasting benefits.
Dry fasting vs. wet fasting – autophagy
Autophagy is the self-cleaning or ‘self-eating process your body uses to clean up all its garbage. It’s your body’s ancient in-house cleaning system, consuming all dysfunctional, unhealthy, and damaged cells, proteins and organelles, and recycling this material so your body can repair and renew itself.
Autophagy supports stem cells regeneration and proliferation, reduces inflammation, and treats neurodegenerative diseases like Parkinson’s, Alzheimer’s, and cancer—as suggested by this study.
Autophagy always happens in the background, usually when you’re sleeping, because that’s when you’re not eating. When your body doesn’t get carbs or proteins, autophagy levels start to increase.
Is dry fasting or water fasting better for autophagy?
Both dry and water fasting increase autophagy; however, autophagy reaches peak levels within 24 hours of dry fasting, while water fasting takes 72 hours. Dry fasting also induces chaperone-mediated-autophagy (CMA), which destroys sick, unhealthy, or pathogenic cells — reversing aging.
Both water fasting and dry fasting contribute to increased autophagy. However, dry fasting is better for autophagy because 1) it gets you into higher levels of autophagy quicker, and 2) it increases CMA, a specific type of autophagy that helps your body rids itself of more harmful pathogenic cells.
CMA (or chaperone-mediated-autophagy) hunts unhealthy, damaged, sick cells, proteins, and organelles—from skin tags, old, saggy skin, scar tissue, pre-cancer, and cancer cells (cysts, tumors, folded proteins), bacteria, parasites, and viruses. All the toxins and poisons which are making you old! Aging results from unhealthy influences in your body, and CMA removes these influences, which makes CMA a highly prized activity. You want more CMA—and you get more CMA from dry fasting.
The destruction of pathogenic cells through autophagy during dry fasting also makes your blood ten times more toxic, so pathogens can’t survive in your system. In this way, autophagy during dry fasting is far more potent than autophagy during water fasting.
Dry fasting vs. wet fasting – ketosis
Whenever you fast and your body runs out of glucose, you start burning fat and making ketones. Ketosis means your body is purely burning fat for energy.
Your body increases ketone production whenever your brain needs more fuel through the process of ketogenesis, which provides a quicker, steadier stream of energy for the brain and muscles.
Every time you sleep, your body makes some ketones. Ketone levels are usually makeup about 6% of your energy usage during an overnight fast, but after three days of water fasting, ketone production increases to more than 60%.
Ketosis is excellent for your brain and increases growth, performance, clarity, and fitness. Ketosis also induces many of the beneficial processes of full-body healing.
Getting into ketosis can take up to a week if you eat less than 50 carbs a day (or 5–10% of your calorie intake) and don’t fast at all. You’re in ketosis when your ketone levels go above 0.5mM—the threshold for ketosis. Ketosis is where your body uses fat as its primary source of energy, not sugar (glucose). The best range to benefits from ketosis can be anywhere from about 1.5–6mM.
During water fasting, your body needs about 2–3 days to get into ketosis. Dry fasting is generally three times faster than water fasting, which means 1 day of dry fasting equals 3 days of water fasting. You can achieve medium to deep levels of ketosis (3.0 – 8.0 mMol) in 24 hours of dry fasting.
Dry fasting increases autophagy and burns fat cells to make water. Every gram of fat can produce 110 grams of metabolic water, which means more fatty acids are ready to be converted into ketones.
Ketosis protects your brain cells because it increases the levels of BDNF (brain-derived neurotrophic factors) protecting it and helps neutrons grow; ketones also protect the brain by reducing oxidative stress and glutamate, basically keeping neurons alive!
Ketosis aids weight loss, cancer, epilepsy, brain injuries, Alzheimer’s, and Parkinson’s. Ketosis encourages metabolic processes that support full-body healing, such as autophagy, stem cell regeneration, and human growth hormone.
Dry fasting vs. wet fasting – metabolism
Many people think fasting weakens you, when in fact, fasting increases your rate of metabolism. As soon as your body realizes there isn’t enough food, your insulin drops, noradrenaline gets secreted, releasing glycogen stores and triggering fat burn. These processes increase your metabolism.
Water fasting studies show resting energy expenditure goes up by at least 10% after fasting for 4 days. During dry fasting, however, this increase in metabolism happens even within 24 hours.
The harsh environment of dry fasting, where your body needs water from every possible avenue, but can’t release toxins through urine, means every cell must dispose of its waste internally while also getting more resources.
So every cell in your body becomes its own little incinerator, burning useless organelles or pathogens inside it for energy, increasing your body temperature (many dry fasters feel feverish or hot, although this may not show on a thermostat). This increased heat also requires more energy to regulate your body’s temperature, which increases metabolism.
Dry fasting vs. wet fasting – muscle loss
Muscle loss has been an urban myth when it comes to fasting. Most people believe that when you fast, you lose tons of muscle mass. Fortunately, that just isn’t so!
Granted, after sugar runs out at the start of a water fasting, which usually happens between 24–36 hours, there’s some loss of skeletal muscle protein. But this amount is relatively negligible.
Muscle protein is made into glucose in your liver through gluconeogenesis ‘making new sugar.’ This process happens just after the glycogen runs out and before fat burn starts, but this doesn’t go on for long, as once insulin levels drop, ketosis kicks in, and fat burn starts. Low insulin levels increase human growth hormone (HGH)—your muscles savior!
Whenever glucose levels in your body go down, HGH levels go up. HGH is a counter-regulatory hormone (like adrenaline and cortisol) that activates fat-burning, which increases the availability of glucose in the body.
Lucky for you, HGH also increases muscle growth and preserves muscle mass. The longer you’re water fasting, the more HGH there is, and the more your muscles are protected.
Multiple studies back this up. According to this article, in one study of water fasting for 40 days, HGH went up as much as 1250%. In another, HGH levels went up as much as 300% during a 5 day fast, and this study of a-day fast shows HGH going up 5 times more than usual.
Dry fasting differs from water fasting because it doesn’t use amino acids from muscles to make glucose—it skips this step completely. The dehydration during dry fasting causes the body to secrete the anti-diuretic hormone ADH, which triggers lipase, breaking down fat cells quickly, which your body uses as energy. During dry fasting, you enter ketosis within 24 hours, so you’re already in fat-burn mode as soon as glucose runs out.
HGH levels are also similar to that 3-4 day fast, so muscles are well protected. Dry fasting can produce more than 5 times the HGH levels of intermittent fasting or three times water fasting.
This study on dry fasting shows how subjects from Ramadan retained muscle mass yet lost significant body fat after the fast. So your muscle mass is well protected during dry fasting.
Dry fasting vs. wet fasting – weight loss
Weight loss has long been the pinnacle of fasting. It’s simple maths, and it works. Fewer carbs (glucose) go into your body, which means more energy is needed to run your body, which means you burn more fat.
However, the immediate weight loss during dry fasting and water fasting can be misleading.
When you fast, glucose (sugar) runs out, insulin drops, and your body taps into its glycogen stores in the liver and muscles. Glycogen binds to water, and the process of metabolizing glycogen leads to water secretion (pee!), so you’ll lose water weight, and actual weight loss only shows several days later, not immediately.
But this doesn’t mean you’re not losing weight; it just means what you see isn’t what you get. Not immediately. To make things more interesting, the appearance of weight loss of dry fasting and water fasting also differ significantly.
In general, research shows you can see a weight loss of about 2 pounds (0.9kgs) per day during water fasting.
In dry fasting, the appearance of weight loss after a fast is even more significant, and according to Dr. Sergey Filonov, you can lose up to 4 to 5 pounds (1–2kgs) in a day!
Does dry fasting burn more fat than water fasting?
Both dry fasting and water fasting burns fat. During water fasting, you burn fat to create fuel for your body. Dry fasting, however, forces the body to metabolize fat for both energy and water, which doubly speeds up the fat-burning rate.
Although the weight loss of water fasting over time drops, the weight loss of dry fasting stays the same, even after day 5–7 of dry fasting. However, because at least half of your body weight is water weight, some of the weight is regained when you break a dry fast and drink water.
Both water fasting and dry fasting suffer from ‘visible’ weight loss numbers at the start, but dry fasting keeps it up because your fat also gets metabolized to create water. Fat is a superior form to create water because 100 grams of fat creates 110 grams of water.
Water fasting can also slow fat burn because your adipose tissues become saturated with water. When your body is fully hydrated, it slows down lipolysis (fat burning).
The key to actual weight loss is ketosis, and both dry fasting and water fasting will get you there. However, dry fasting speeds up ketosis quickly—in less than 24 hours of dry fasting, you’ll be in nutritional ketosis. As opposed to water fasting, which takes up to 48–72 hours to enter nutritional ketosis. Ketosis helps to sustain weight loss, and you want to be in ketosis as often as possible.
Dry fasting can be more efficient than water fasting for weight loss. However, it requires discipline and can be used for weight loss if you prepare correctly for the dry fast and break the dry fast carefully, refeeding over several days – drawing out your high ketosis levels.
Refeeding is twice the length of your fast. So if you dry fast for 24 hours, you should refeed for 48 hours—no salt or carbs. This way, your weight loss is sustained.
Water fasting may be better for weight loss, in some ways, as you can do over time and with less precautionary measures. You should still be careful when breaking the fast. Still, since you don’t need to worry about the remineralization as much as water fasting—your body is susceptible to salt and water after a dry fast—you can be less cautious exiting the fast without worrying about weight regain.
Intermittent water fasting or alternate day water fasting is the easiest, fuss-free way to lose weight. You don’t have to be too concerned about exiting and preparation before the fast with short, cyclical fasting—because the more often you stay in ketosis, the more your body gets used to fat burning, and the more likely you are to lose weight.
Water fasting can also be better suited to those who have diabetes, as they often need to take medication that makes them pee a lot—which could dehydrate them in a dry fast. Insulin levels drop in both dry and water fasting, so it might be easier to water fast to regulate insulin levels simply.
Dry fasting vs. wet fasting – summary
Both dry fasting and water fasting are inexpensive, effective ways to boost your health. You can do both at home, on your own time, and with no medical supervision. Dry fasting can more beneficial and efficient for your rejuvenation but may be more challenging and require more preparation and exit measures. Water fasting can be a more straightforward method to boost your health in smaller, cyclical doses (intermittent water fasting or alternate-day fasting). Longer medical water fasts can be an effective way to improve insulin-related problems such as diabetes.
For more on water fasting and dry fasting for weight loss and age reversal, check out my video course, 25 Again! The Dry Fasting Lifestyle For A Younger, Slimmer You.
***Disclaimer: I am not a doctor/ physician, and although I have a bachelor’s degree in Biomedical Science, I cannot and do not hold myself to be a medical professional (“Medical Provider”). This article does not contain medical /health advice. The medical/ health information here is for general and educational purposes only. It is my opinion, based on my research and personal experience, and not a substitute for professional advice by your health care provider. Please consult with a professional before acting on the information here, and do not disregard medical advice or delay seeking medical attention because of anything you read in this article. THE USE OR RELIANCE OF ANY OF THE INFORMATION ON THIS WEBSITE IS SOLELY AT YOUR OWN RISK.***
- Galluzzi L, Pietrocola F, Bravo-San Pedro JM, et al. Autophagy in malignant transformation and cancer progression. EMBO J. 2015;34(7):856-880. doi:10.15252/embj.201490784
- Laffel, L. (1999), Ketone bodies: a review of physiology, pathophysiology and application of monitoring to diabetes. Diabetes Metab. Res. Rev., 15: 412-426. https://doi.org/10.1002/(SICI)1520-7560(199911/12)15:6<412::AID-DMRR72>3.0.CO;2-8
- Masood W, Annamaraju P, Uppaluri KR. Ketogenic Diet. [Updated 2021 Jun 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK499830/
- MELLANBY, K. Metabolic Water and Desiccation. Nature 150, 21 (1942). https://doi.org/10.1038/150021a0
- Maalouf M, Rho JM, Mattson MP. The neuroprotective properties of calorie restriction, the ketogenic diet, and ketone bodies. Brain Res Rev. 2009;59(2):293-315. doi:10.1016/j.brainresrev.2008.09.002
- Zauner C, Schneeweiss B, Kranz A, et al. Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine. Am J Clin Nutr. 2000;71(6):1511-1515. doi:10.1093/ajcn/71.6.1511
- Owen OE, Smalley KJ, D’Alessio DA, Mozzoli MA, Dawson EK. Protein, fat, and carbohydrate requirements during starvation: anaplerosis and cataplerosis. Am J Clin Nutr. 1998;68(1):12-34. doi:10.1093/ajcn/68.1.12
- Hartman ML, Veldhuis JD, Johnson ML, et al. Augmented growth hormone (GH) secretory burst frequency and amplitude mediate enhanced GH secretion during a two-day fast in normal men. J Clin Endocrinol Metab. 1992;74(4):757-765. doi:10.1210/jcem.74.4.1548337
- M L Hartman, J D Veldhuis, M L Johnson, M M Lee, K G Alberti, E Samojlik, M O Thorner, Augmented growth hormone (GH) secretory burst frequency and amplitude mediate enhanced GH secretion during a two-day fast in normal men, The Journal of Clinical Endocrinology & Metabolism, Volume 74, Issue 4, 1 April 1992, Pages 757–765, https://doi.org/10.1210/jcem.74.4.1548337
- Fahrial Syam A, Suryani Sobur C, Abdullah M, Makmun D. Ramadan Fasting Decreases Body Fat but Not Protein Mass. Int J Endocrinol Metab. 2016;14(1):e29687. Published 2016 Jan 2. doi:10.5812/ijem.29687
- Kerndt PR, Naughton JL, Driscoll CE, Loxterkamp DA. Fasting: the history, pathophysiology and complications. West J Med. 1982;137(5):379-399
- 20 Questions and Answers about Dry Fasting’, Dr. Sergey Filonov, Moscow, 2019, Siberika Publishing.
- MELLANBY, K. Metabolic Water and Desiccation. Nature 150, 21 (1942). https://doi.org/10.1038/150021a0