Water fasting is the most extreme form of fasting. If you practice it, you should watch how your body reacts and responds to it. Water fasting is an effective way to lose weight quickly, but you should focus on how to do it sustainably.
Different individuals have different metabolisms. If a particular form of fasting suits one person, it does not mean it will work for you. Suppose you are thinking of a water fast to lose weight; several factors will affect your results. Consult a doctor or dietician because there are other sustainable ways of losing weight, like intermittent low-carb fasting.
Different intermittent fasting techniques like the 16/8, 5/2, or OMAD plans are as effective as a water fast to achieve weight loss. You must exercise caution if a water fast appeals to you. There should be a solid plan for what you will eat before commencing the fast and how you will end it.
Check out for negative indicators like fatigue, stomach pain, or overtiredness. These are red flags indicating that you should stop your water fast for the sake of your health. Do not be stubborn and linger on with the water fast, or severe health complications could occur.
- What is Water Fast?
- Tips and Suggestions for a Water Fast
- 10 Signs Indicating that you Should Cease Water Fast
- Frequently Asked Questions
What is Water Fast?
A water fast is a diet regimen usually carried on for three days where you do not consume any food or drink except water. Three-day water fast has a lot of benefits, like autophagy, a reduction in inflammation, an immune system reset, weight loss, improvement in leptin and insulin sensitivity, lowered risk of chronic diseases, an increase in good cholesterol, a decrease in triglyceride levels, lowering of blood pressure, as well as a reduction in the chemotherapy side effects of cancer patients.
Tips and Suggestions for a Water Fast
While intermittent fasting allows you to eat during the eating windows, a water fast is rigid, demanding, and downright brutal if you are new to it. Here are a few tips to make this process easier.
Before embarking on a three-day water fast, try intermittent fasting to see if it suits you. When you are used to going without food for an extended period daily, you could try a 24-hour fast. When you are comfortable with this, try a three-day water fast.
Three-day water fast is highly demanding on your body and will drain your energy. It is advisable not to exercise during the water fast so that your energy reserves last for three days.
Don’t Fast if You Are Unwell
If you suffer from chronic diseases, please do not attempt a three-day water fast. Whatever your weight goals, your health should always be your priority. Do not underestimate water fast; it is never easy, even in the best circumstances. Do not put your health at risk for a water fast. If you insist, get a doctor’s approval before starting the fast.
Consume High Energy Foods Before The Fast
You must prep your body for the challenge of water fast. Ideally, you should not experience hunger pangs on the first day of the fast. To ensure this, consume high-energy foods before the fast. Some examples are brown rice, bananas, fatty fish, quinoa, oatmeal, lentils, and avocado.
Schedule the Water Fast Right
Your water fast should not impede your work. To ensure this, schedule the fast for the last three days of the week so that it does not take a heavy toll on your energy. Instead of the beginning of the work week, your fast will be better off if done from Friday to Sunday.
If You are Unwell, Stop Immediately
Do not jeopardize your health for the sake of water fast. If you feel unwell, stop immediately. There are many ways to lose weight, and you should not sacrifice your health at the altar of weight loss.
10 Signs Indicating that you Should Cease Water Fast
A water fast can be dangerous if not done correctly, and even when all the rules are followed, many issues may arise. Look out for these signs indicating that you should immediately stop your water fast:
Your stomach has many natural acids that sit dormant and idle when fasting. These acids may come from acid reflux or other symptoms like intestinal wall damage, ulcers, stomach pain, burning sensation, or even chest pain when you fast. To relieve the stomach pain, you must consume alkaline substances that will increase your gut pH level.
Try to have warm water or a half spoon of sodium bicarbonate or baking soda, which are alkaline substances best for settling your stomach acids. Stop fasting and consult a doctor if the pain persists.
Water fasting could affect thyroid-stimulating hormones released by the pituitary gland located in the brain, which could affect the T3 (Triiodothyronine) and the T4 (thyroxine) hormones released by the thyroid gland. These hormones significantly affect metabolism as they regulate energy and body temperature. 
If thyroid function is poor, you will feel tired and have difficulty losing weight. The function of the thyroid gets down-regulated because of nutritional deficiency and manifests as throat pain. If you experience throat pain while water fasting, stop.
Loss of Consciousness
Two common symptoms seen during water fasting are loss of consciousness and a feeling of lightheadedness. These could be due to low blood pressure, low insulin levels, high blood sugar, low electrolytes, nausea due to fasting, and dehydration. Loss of consciousness can also be due to mineral and vitamin deficiencies like iron, B12, and magnesium.
Hyperglycemia, or high blood sugar, can be especially dangerous as it can cause DKA (diabetic ketoacidosis), wherein the body, without insulin, produces toxic substances. If you feel lightheaded or have fainted, lie down with your feet at a higher level. Stop water fasting and consult a doctor immediately.
Nausea and Vomiting
Some people will also experience nausea and vomiting during water fasting. This could be due to acid reflux. An excess of acid in your stomach will make you nauseous and cause stomach pain and vomiting. The vomit could include bile, the liver’s digestive enzyme that lies unused in your stomach.
If you start vomiting, stop fasting immediately and drink water and juice. You can also have ginger, plain or mint tea, or even lemon soda; these drinks help with nausea.
Some people encounter breathing problems while fasting due to the salt shortage. If you drink water without magnesium or sodium, you may experience restricted breathing. Consider having pink salt mixed with water. After 15 minutes, you may feel better, and you should stop fasting.
Your sleep-wake cycle is regulated by the melatonin hormone released by the pineal gland. According to studies, water fasting can affect hormone production as the pineal gland needs a small amount of glucose for optimal functioning . However, some animal studies suggested that obese people may not be more affected by issues related to insomnia than leaner people.
Another reason for chronic insomnia could be the rising cortisol levels due to prolonged fasting. In extreme cases, this may even create mental health problems, so stop water fasting immediately in this case.
Weakness, Headache, And Extreme Fatigue
During water fasting, you may feel severe fatigue because your body is deprived of glucose, the fuel needed for normal functioning. Many people will experience weakness and energy loss as symptoms of fasting while they perform their daily activities.
So, when water fasting, be careful about expending your energy on intensive exercises. Instead, opt for less intensive workouts likely to cause fatigue, like walking and yoga. Also, try napping for an hour during the day to boost your energy levels. Some also have headaches during fasting because of caffeine withdrawal . If you have any of these symptoms and feel they are going out of hand, please stop your water fast.
Lack of Focus
Water fasting causes mood swings and irritability because of constant hunger pangs, making it difficult for you to concentrate. The hormone responsible for hunger is called ghrelin, which also affects memory performance.  
You will find it challenging to tolerate hunger when your body cannot shift into ketosis to use stored fats for energy. In this case, you may have to break the water fast and opt for a fat-only diet without carbs that will keep your body in the ketosis stage. When this happens, your body will continue the process of autophagy without any rise in insulin levels. MCT oils are beneficial to keep your body in ketosis.
Constipation or Diarrhea
Diarrhea can result from excess water and salt in the gastrointestinal tract. The chances of catching diarrhea during water fasting are low. However, there are chances that you may develop diarrhea after you break your fast because the bowel’s optimal functionality reduces when it is not used for an extended period.
Another reason for diarrhea after the water fast could be choosing the wrong diet after breaking the fast. After undergoing extended water fast, you should eat proper foods to avoid IBS (inflammatory bowel disease) or refeeding syndrome, which can sometimes be fatal. 
During the early days of fasting, you may have constipation as your body will lose a lot of fluid or even undergo diuresis in the initial fasting days. Because of a lack of fiber in your diet, constipation could become intolerable, forcing you to break off the fast.
Chills and Hot Flushes
You may experience a drop in your body’s temperature during water fasting as the blood flow increases to use the stored fat for energy. Yet another reason for feeling cold could be because of a fall in blood sugar levels while you water fast. Consider light exercises to warm your body; you could also have green tea. If you are feeling hot, it could indicate pre-menopausal hot flashes for women. Please discuss the issue with your doctor and follow their advice on continuing your water fast.
Frequently Asked Questions
What is water fast?
A water fast is when you do not eat or drink anything but water. There is no set duration for a water fast, but experts recommend that anywhere from 24 hours to 3 days is the maximum time to go without food.
What are the hardest days of water fasting?
Water fasting will be challenging and demanding after day two. No matter how many times you fast, you will find day three to be the most difficult, as that is when ghrelin, the hunger hormone, peaks in your body.
How do you know when to stop water fasting?
If you experience symptoms like nausea, vomiting, dizziness, loss of consciousness, constipation, diarrhea, or abdominal pain, you should immediately stop your water fast.
What happens if you don’t drink enough water during water fasting?
Dehydration is a severe risk when it comes to water fasting. Excessive fatigue, hunger, and irritability are common side effects of water fasting. A lack of water intake during water fasting can lead to increased urinary tract infections and kidney stones.
What should I eat after a water fast?
When you break a water fast, you should be careful not to overload your system. Some gentle foods to break your fast are smoothies, dried fruits, vegetables, soups, healthy fats, and fermented foods.
How much weight do you lose when water fasting?
You can lose weight quickly when you do a water fast. According to studies, you can lose 0.9 kilograms daily while water fasting. However, this body mass loss comes from water loss, carbs, and muscle mass, not fat.
The entire focus of fasting is to improve your health. And if you were wondering if a water fast could make you sick, you know now that it can. If you experience any uncomfortable health issues, take a call and decide if a water fast is really for you or not. There are other, much healthier alternatives out there for losing weight.
If you are undertaking a moderate fast of 16–24 hours, there will be symptoms like irritability and hunger pangs, but that should not make you break your fast.
Severe symptoms should not be ignored and should be reason enough for you to break your water fast. Consider switching to a less restrictive fast that allows you to function normally without breaking a sweat.
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