What Are the Benefits (and Dangers) of Water Fasting?

Fasting is prevalent since the Middle Ages for religious and health reasons. Water fasting is promoted for its “so-called benefits” that include:

1. Modulation of hormonal balance in the body, particularly reducing levels of insulin and corticosteroids.
2. Recalibrate your brain centers that control hunger and appetite. Thus, it is believed to improve your eating behavior so that you tend to binge less and have better satiety.
3. Reduced inflammatory protein levels in the blood (e.g., C-reactive protein, substance P) may improve cellular functioning and lower the risk of chronic health conditions.
4. Reduced insulin levels and improved insulin sensitivity and fat burning.
5. Claims regarding protection from cancer and other chronic diseases.
6. Ketosis develops in the first three days of fasting as a metabolic consequence of fats being burnt for energy instead of glucose. A mild state of ketosis is believed to have neuroprotective effects by reduced free radical production.
7. Ketosis results in improved fat burning and improved basal metabolic rate, causing rapid weight loss.
8. A reduction in about 10 percent body weight is associated with improved joint and spine function, reduced stress over the heart, improved glucose levels in those with prediabetes, and reduced blood pressure values.
9. Reduced cholesterol and triglyceride values in the blood, reducing the risk of blood vessel diseases and dementia.
10. Studies concur that any type of fasting can improve the gut microbe number and diversity. Fasting causes an increased level of the beneficial short-chain fatty acid formation in the gut, which may help with intestinal immunity and provide relief in certain autoimmune diseases.

You must be aware of the possible adverse effects caused by water fasting. Prolonged fasting is a dangerous practice. You must understand that calorie restriction must be coupled with physical activity and weight training for healthy weight loss.

Water fasting has many side effects, which include:

1. Fatigue, dizziness, and nausea due to low blood sugars.
2. Over the next seven days, you may experience constipation, dehydration, and not being able to tolerate cold temperatures.
3. Increased uric acid and creatinine blood concentrations (probably secondary to muscle breakdown) during fasting, affecting kidneys in long run and causing kidney stones.
4. Constant water fasting (or any fad diet) increases the chances of gall bladder inflammation and gallstones.
5. Decreased kidney function due to possible dehydration if water fasting is done in a hot environment.
6. Long-term ketosis (over weeks) can lead to metabolic acidosis in the body that can negatively affect the body cells in general and heart cells.
7. Chronic water fasting can trigger calcium release from bones, causing bone loss and a tendency to fracture.
8. Electrolyte imbalances due to low water consumption and the absence of nutrients can lead to a significant loss of sodium, magnesium, and potassium from the body and may trigger dangerous arrhythmias in the heart. They may affect brain and liver health.
9. The more you fast, the body starts interpreting it as stress and lowers your metabolism, causing you to gain weight, get migraines, feel sluggish, and get mood swings. 
10. Water fasting may trigger bingeing behavior in those predisposed to eating disorders.

Intermittent fasting for about 16 hours a day is mostly safe and even beneficial for the body if you drink enough water and make sure your electrolytes are in order.

• Fasting triggers the phenomenon of “autophagy” in the body cells.
• Autophagy is simply the process by which the body destroys certain cellular components that are aging or getting damaged over time.
• Such damaged organelles are potential for cell inflammation, aging, or cancer. 

Scientists believe that autophagy is a natural anticancer mechanism that limits necrosis and inflammation and prevents cells with defective components or DNA from replicating.

Depending on your comorbidities, age, and lifestyle, the doctor could suggest a fast that will work for you. Several studies report the promise of intermittent fasting. However, these studies are done only for months. It is unclear if the benefits will remain for years if the diet is continued throughout life.