Fasting, a method of restricting food intake, has been practiced for thousands of years. Water fasting is a type of fast that restricts everything except water. It has become more popular in recent years as a quick way to lose weight.
Studies have shown that water fasting could have health benefits. For example, it may lower the risk of some chronic diseases and stimulate autophagy, a process that helps your body break down and recycle old parts of your cells.
That said, human studies on water fasting are very limited. Moreover, it comes with many health risks and is not suitable for everyone. Water fasting is a type of fast during which you cannot consume anything besides water.
Most water fasts last 24–72 hours. You should not follow a water fast for longer than this without medical supervision.
Reasons for why people try water fasting
- Religious or spiritual reasons
- To lose weight
- For “detoxing”
- For its health benefits
- Preparing for a medical procedure
The main reason why people try water fasting is to improve their health.
In fact, several studies have linked water fasting with some impressive health benefits, including a lower risk of certain cancers, heart disease, and diabetes.
Water fasting may also promote autophagy, a process in which your body breaks down and recycles old, potentially dangerous parts of your cells. Popular diets like the lemon detox cleanse are modeled after the water fast. The lemon detox cleanse only lets you drink a mixture of lemon juice, water, maple syrup, and cayenne pepper several times per day for up to 7 days.
However, water fasting has many risks and can be very dangerous if followed for too long.
How to Follow Water Fasting
There are no scientific guidelines on how to start water fasting. However, several groups of people should not water fast without medical supervision. This includes people with gout, diabetes (both types 1 and 2), eating disorders, older adults, pregnant women, and children.
If you have never water fasted before, it’s a good idea to spend 3–4 days preparing your body for being without food. You can do this by eating smaller portions at each meal or by fasting for part of the day.
Water fast (24–72 hours)
During a water fast, you are not allowed to eat or drink anything besides water. Most people drink two to three liters of water per day during a water fast.
The water fast lasts for 24–72 hours. You should not water fast for longer than this without medical supervision because of health risks. Some people may feel weak or dizzy during a water fast and may want to avoid operating heavy machinery and driving to avoid causing an accident.
Post-fast (1–3 days)
After the water fast, you should resist the urge to eat a big meal. This is because eating a large meal after a fast may cause uncomfortable symptoms.
Instead, break your fast with a smoothie or smaller meals. You can start introducing larger meals throughout the day as you feel more comfortable.
The post-fast phase is especially important after longer fasts. This is because you may be at risk of refeeding syndrome, a potentially fatal condition in which the body undergoes rapid changes in fluid and electrolyte levels.