Intermittent fasting
![Intermittent fasting is alternating between eating and fasting during specific hours of the day. You can drink water while fasting, but you should be under medical supervision if you'd like to fast for more than one to three days.](https://images.medicinenet.com/images/article/main_image/does-drinking-water-increase-fasting-blood-sugar.jpg?output-quality=75)
Recent research has demonstrated the benefits of intermittent fasting. Unfortunately, understanding what you can eat or drink during a fast can get confusing. One of the most common questions is: “Can you drink water while fasting?”
The answer to this isn’t straightforward and depends on factors such as the purpose and the type of your fast. This article will explore whether you can drink water during certain fasts and what other factors you should be aware of.
A widespread weight-loss practice includes intermittent fasting, in which you alternate between eating and fasting during specific hours of the day. While regular diets focus on what you eat, the goal of intermittent fasting is to monitor when you eat. Research has found this an effective method for managing weight.
A 2015 study found that eating frequently is linked to obesity or being overweight. According to the study, people who ate more than four times a day were 50% more likely to be overweight or obese than those who ate a maximum of three times a day. The study involved more than 18,000 American adults over 20.
One of the most common intermittent fasting practices is eating during an eight-hour period of your choice — typically from 10 am to 6 pm — and fasting for the remaining 16 hours. This intermittent fasting leads to a period of zero calorie intake after your body has burned the calories you ate during your last meal, causing your body to break down stored fat — a process called metabolic switching.
Research shows intermittent fasting reduces the risk of several chronic conditions, such as age-related neurodegenerative diseases, inflammatory bowel disease, and cancers. Intermittent fasting also enhances brain functions, especially verbal memory, and burns body fat without sacrificing muscle mass. Since intermittent fasting focuses mainly on limiting your calorie intake, though, there’s no restriction on drinking water.
Water-only fasting
Water fasting involves drinking only water while abstaining from solid food for a period of time generally lasting one to three days (or longer, if you are under direct medical supervision). There are many reasons to go on a water fast. A primary reason to start is to reduce caloric intake to lose weight.
Research suggests there are some benefits of water fasting. A 2021 study involving 45 healthy participants found that water-only fasting reduces the risks of metabolic disorders and inflammation-related conditions. According to the study, fasting slows down your aging process and causes a noticeable reduction in body weight, waist circumference, and body mass index (BMI). Water-only fasting also has other health benefits.
Lowers your blood pressure
A 2014 study involving 174 participants with hypertension found that water fasting helps lower blood pressure. According to the study, medically supervised water-only fasting reduced the participants’ blood pressure considerably. At the end of the study, the participants did not feel the need to take any other medication for their hypertension.
Could improve heart health
According to research, water-only fasting lowers the risk of cardiovascular diseases. One such study involving 30 healthy participants found that water-only fasting increases the red blood cell count, human growth hormone, and hemoglobin. The study also recommends frequent short-term fasting as a method to counter the risks of metabolic diseases. Still, more research is needed to understand the long-term effects of water-only fasting on heart health.
Improves kidney function
A 2018 study found that water-only fasting improves kidney function, reduces oxidative stress, and lowers bad cholesterol (LDL cholesterol) levels. Unchecked oxidative stress causes a spike in the number of reactive molecules in your body that can lead to cell and tissue damage.
![](https://images.medicinenet.com//images/slideshow/foods-that-arent-as-healthy-as-you-think/foods-that-arent-as-healthy-as-you-think-s1-bulletproof-coffee.jpg)
SLIDESHOW
Foods That Aren't as Healthy as You Think See SlideshowFasting for medical procedures
Some medical procedures require you to be on a water-only diet for roughly eight to 12 hours before the procedure. This ensures that you’re on an empty stomach to minimize the risk of any complications during surgery.
You should also fast before some medical procedures to prevent lung damage. Under normal circumstances, your body prevents the contents of your stomach from entering the lungs, but anesthesia limits your body’s ability to do this. When food or stomach acids enter your lungs, that can lead to infections and lung damage.”
Can you drink water while fasting?
While most health experts suggest you can drink water while fasting, that depends on your purpose. Those who fast for religious purposes may forgo water as well, even if that is not the healthiest decision.
Others may fast for their health. Fasting burns calories and helps keep your weight in check. A lot of research indicates fasting is good for health, whether that involves intermittent fasting, water-only fasting, or both. However, the long-term effects of such fasts are still to be understood. Your body does not get enough calories when you fast, and this could cause:
- Dehydration
- Inadequate electrolyte levels in your body
- Heart arrhythmias
- Lower metabolism
- Constipation
- Erratic blood sugar levels
- Lightheadedness
If you think a water-only fast is not for you, there are other options you can explore. In addition to water, you can add other clear liquids to your diet. These include:
- Fruit juices without pulp
- Sports drinks
- Carbonated drinks
- Tea and coffee
- Clear broths
On the other hand, you may wish to avoid items such as milk and orange juice, as they contain more nutrients and may take more work for your metabolic system to break down.
If you want to lose weight, check with your doctor whether fasting is safe and what you can eat or drink during such fasts.
In addition to children and teens under 18, the following people should avoid fasting:
- Pregnant women
- Women who are breastfeeding
- Individuals with diabetes
- People with a history of eating disorders
Health News
- One Death, 10 Hospitalizations in Listeria Outbreak Tied to Peaches, Plums
- Charity Scams Get Active Over the Holidays: Expert Tips to Avoid Them
- Too Few Seniors Get Follow-up Care After a Serious Fall
- AI Could Predict a Nonsmoker's Risk for Lung Cancer
- Breast Cancer Rates Higher in Urban vs. Rural Areas
More Health News »
Health Solutions From Our Sponsors
Beaumont Health: "What is fasting?"
Bratislavské Lekárske Listy: "Effects of complete water fasting and regeneration diet on kidney function, oxidative stress and antioxidants."
Clinical and Translational Medicine: "Five-day water-only fasting decreased metabolic-syndrome risk factors and increased anti-aging biomarkers without toxicity in a clinical trial of normal-weight individuals."
Hospital for Special Surgery: "Can You Drink Water While Fasting?"
Integrative Medicine: A Clinician's Journal: "Alan Goldhamer, DC: Water Fasting—The Clinical Effectiveness of Rebooting Your Body."
Johns Hopkins Medicine: "Intermittent Fasting: What is it, and how does it work?"
The Journal of Nutrition: "Eating Frequency Is Positively Associated with Overweight and Central Obesity in US Adults."
Nutrition, Metabolism, and Cardiovascular Diseases: "Randomized cross-over trial of short-term water-only fasting: Metabolic and cardiovascular consequences."
Oates, J. R., Sharma, S. StatPearls, "Clear Liquid Diet," StatPearls Publishing, 2022.
Oxidative Medicine and Cellular Longevity: "Oxidative Stress: Harms and Benefits for Human Health."
Top Can You Drink Water While Fasting Related Articles
Can the Amount of Water You Drink Affect Hair Loss and Growth?
Drinking enough water helps keep your skin soft and supple. Staying hydrated helps fight hair loss and helps your hair grow.Can Drinking Water Lower Your Blood Pressure?
Keeping well hydrated by drinking six to eight glasses of water daily (even more if working in hot and humid conditions) is beneficial for the blood pressure. High blood pressure (BP) or hypertension is a condition caused by the persistent high pressure of blood against the walls of arteries. It is also called systolic pressure (constantly greater than 139 mmHg) or diastolic pressure (constantly more than 89 mmHg).Can Drinking Water Stop Kidney Failure?
While drinking more water can help boost kidney function, there is no evidence that suggests that it can prevent the progress of kidney failure.Can You Get Rid of a UTI By Drinking Water?
UTI stands for urinary tract infection and it describes when your urinary system gets infected. While the effects of drinking water to flush out or get rid of UTIs is not proven, there has been a link between drinking over 2.2 liters of water daily and a decreased risk for UTIs.Is It Better to Drink Cold Water or Room Temperature Water?
The effects of drinking both room temperature and cold water vary by person, specifically by health, age, and the amount being consumed.Fasting
Fasting: It's simple and trending, though it's been around for thousands of years. Find out whether it might be a good option for you, and what the risks and benefits are.How Much Water Should You Drink Based on Your Weight?
Generally, you should aim to drink about 64 ounces of water per day. Check out the center below for more medical references on nutrition, including multimedia (slideshows, images, and quizzes), related disease conditions, treatment and diagnosis, medications, and prevention or wellness.Hydration Quiz
Do you know how much water you should be drinking on a daily basis? It may not be what you think. Take this quiz to learn how to stay hydrated.Is Drinking Distilled Water Good or Bad for You?
Distilled water is considered the purest form of water. There are both potential risks and benefits of drinking distilled water.7 Ways Water Benefits the Body
Drinking water benefits digestion, metabolism, toxin elimination, and other functions. Water promotes weight loss and helps prevent dehydration. Health benefits of hydration include improvements in mood, skin health, and ability to work out.The Best Times to Drink Water
Benefits of drinking water: general hydration, as an aid in brain function, to promote weight loss, to replace sweat loss after exercise, when you’re sick, and more.What Happens to Your Body When You Drink Enough Water?
You might be surprised at how well your body works when you drink enough water. Find out exactly what can go right when you get your H2O.What Is the Healthiest Water to Drink?
Mineral water and alkaline water may be some of the healthiest types of water because they provide your body with essential nutrientsWill Drinking More Water Help With Edema?
Edema is the technical term for swelling, and it happens when fluid collects under the skin. Drinking water may help if you have mild edema.Will Drinking Water Lower Blood Sugar?
Diabetes mellitus is a chronic health condition that affects your body’s ability to break down food into energy. One study suggests that routinely drinking water might prevent the onset of hyperglycemia.