In recent years, the 36-hour fast has gained popularity among fitness enthusiasts eager to enhance their health and metabolic performance. However, neurologist Dr. Sudhir Kumar of Apollo Hospitals in Hyderabad has issued a cautionary note regarding this extended intermittent fasting method, pointing out that it may not be suitable for everyone. While some individuals may experience benefits such as increased insulin sensitivity and improved mental clarity, serious health risks are associated with this practice. During a 36-hour fast, individuals typically consume only water, plain tea, or black coffee without sweeteners. Dr. Kumar views this fasting longer than standard intermittent fasting as a method that can lead to both potential benefits and overlooked dangers.

One of the touted advantages of a 36-hour fast is the possibility of enhanced insulin sensitivity, which may aid in regulating calorie intake. Extended fasting can kickstart autophagy, the process by which the body removes damaged cells, although the evidence for this in humans requires further research. Many individuals report experiencing sharper focus and greater concentration, likely as the body transitions into fat-burning mode and produces ketones for energy. This transition can also help individuals better identify their true hunger signals and reduce mindless snacking, ultimately promoting healthier long-term eating habits.

Despite these potential benefits, Dr. Kumar warns that long fasting periods can lead to hydration issues and electrolyte imbalances since essential minerals like sodium and potassium are not replenished. Low blood sugar is another risk, potentially resulting in dizziness, irritability, and headaches, particularly for those engaging in intense physical activity while fasting. Additionally, elevated cortisol levels could disrupt sleep, causing restlessness. Frequent 36-hour fasts may lead to muscle loss if regular eating days do not provide adequate protein, and there is a risk of exacerbating digestive issues, especially if tea or coffee is consumed on an empty stomach.

Certain groups should avoid attempting a 36-hour fast. Individuals with diabetes risk hypoglycemia, while those with hypertension and on diuretics may face life-threatening fluid and salt imbalances. People with extremely low Body Mass Index (BMI), eating disorders, or food-related anxiety should also stay clear of this fasting technique. Pregnant and breastfeeding women are advised against prolonged fasts due to increased nutritional needs. Dr. Kumar debunks the myth of fasting as a detox method, asserting that the liver and kidneys are responsible for filtering waste and maintaining balance without the need for fasting.

For healthy adults wishing to try a 36-hour fast, several precautions should be taken. Opting for electrolyte-rich water can help maintain mineral levels, while avoiding high-intensity workouts can reduce the risks of fatigue and dehydration. Gradual reintroduction of light, protein-rich foods is essential when breaking the fast to minimize digestive discomfort. Long fasts should not be done frequently, with a general recommendation of once a month as the upper limit for most individuals. Dr. Kumar emphasizes that while an occasional 36-hour liquid fast may be harmless for healthy individuals, it is not essential for fitness or detoxification purposes. Listening to one's body is crucial, and any signs of palpitations or significant fatigue during the fast should prompt immediate discontinuation of the practice. Overall, balance, awareness, and caution are vital when exploring fasting trends.