After reading the headline to this article, you’re probably wondering, what is water fasting?
The term “water fasting” is exactly what the name implies: going without food and drinking only water for a certain amount of time.
Usually, people will embark on a water fast from 24 to 72 hours, although longer water fasts may be done in a medical setting and with medical supervision.
This type of fasting is different from intermittent fasting, in which a person follows a shortened number of hours in which they eat each day. For example, in a 24-hour period, a person may fast for 20 hours and consume their foods within the confines of the remaining four-hour window.
When a person practices water fasting, the body quickly uses up stored sugar (glycogen) and starts to use fat stores for energy, producing ketones. This process also results in hormonal and metabolic changes along the way.
Water Fasting Benefits
Here’s a look at some potential water fasting benefits:
Rapid weight loss with improved short-term metabolism
It may come as no surprise that water fasting is associated with reductions in body weight. After all, when all calories are removed from a person’s usual intake, the number on the scale is likely to drop rather quickly. Much of this weight loss comes from water and stored sugar, but some fat loss may happen as well. Additionally, short-term studies do show benefits of fasting protocols on blood lipids, blood sugars, and insulin sensitivity. Of note, these improvements probably disappear once people return to their regular diets, unless they can make some longer-lasting health-promoting changes to their diets.
Reduction in blood pressure (at least in the short-term)
Studies on water fasting in people with elevated or high blood pressure have shown reduction in blood pressure to healthier levels after short periods of time following a water fast. Ongoing studies are needed to understand the effects of reintroducing foods on blood pressure.
Increased cellular cleanup
Your body’s cells have an ongoing “cleaning” or “recycling” process known as autophagy. This process clears away debris and damaged cellular components, thereby improving the body’s efficiency. Studies completed in animals have shown that fasting “turns on” this process, and initial research suggests it may do the same in people. Regardless, we’ve got a long way to go to understand the degree to which fasting to increase autophagy can support overall health and or disease prevention.
Risks of Water Fasting
Fasting and water fasting are often linked with a range of unpleasant side effects, including dizziness, nausea, headaches, sleep disruption, or fatigue. These side effects may improve over time but are often disruptive enough to make people discontinue the fasting process. Some potential side effects of water fasting include:
Increased risk of gout attacks
During periods of fasting, uric acid levels rise in the blood. This increase can trigger painful gout flareups in people who are prone to experiencing them.
Decrease in muscle mass and energy levels
In longer fasting situations, the body burns fat as well as some muscle along with it. During this time, people often report feeling tired and weak; athletic performance may also suffer.
Risk of refeeding syndrome
If a person fasts for more than a few days and then suddenly eats a larger amount of carbohydrates, the body can respond by shifting electrolytes (like potassium, magnesium, and phosphate) so quickly that it leads to swelling, irregular heartbeats, or even heart failure. This phenomenon, known as “refeeding syndrome,” is the primary reason why doctors emphasize the importance of slow and careful refeeding practices after longer periods of fasting.
Water Fasting Isn’t Safe for Everyone
People who take medications for blood pressure, diabetes, or mental health should use extra caution when considering water fasting, as periods of fasting can make these types of drugs too strong. Water fasting is also considered unsafe for kids, teens, women who are pregnant or nursing, people who are underweight, and anyone with an active eating disorder or a history of an eating disorder.
Overall, participating in water fasting alters the way the body works, at least temporarily. Although it may bring short-term benefits like reductions in blood pressure and quick weight loss, there are also very real risks, like dizziness, decreased energy, risk of gout flareups and refeeding syndrome.
Ultimately, the safer call may be to consider options like intermittent fasting or gradual diet modifications to help provide the same benefits without the elevated risks. If you are considering water fasting or any other drastic change to your health regimen, be sure to discuss it with your healthcare professional first.
