New Delhi, 25 August 2025: In recent years, intermittent fasting has gained popularity as a powerful tool for weight loss, metabolic health, and even mental clarity. Among the more intense forms of fasting is the 36-hour fast, a prolonged routine that involves abstaining from all food for 36 hours straight, followed by a refeeding period. While some individuals report impressive weight loss results from this approach, not all experiences are positive.
This is the story of a 29-year-old woman who lost 5 kilograms in just one month by practicing 36-hour fasting. However, alongside the rapid weight loss came unexpected health issues: bloating, acidity, and insomnia. Her experience sheds light on the less-discussed side effects of extended fasting and offers important lessons for anyone considering extreme dietary changes.
Why 36-Hour Fasting Is So Popular
Intermittent fasting comes in various forms, from the widely practiced 16:8 method (16 hours fasting, 8 hours eating) to alternate-day fasting and prolonged fasts. The 36-hour fast sits on the more extreme end of the spectrum and typically follows this schedule:
- Day 1: Eat dinner by 8 p.m.
- Day 2: No food intake for the entire day.
- Day 3: Break the fast at 8 a.m.
Proponents of this method claim it accelerates fat loss, enhances insulin sensitivity, supports autophagy (a process of cellular repair), and improves discipline. For those who have plateaued with traditional dieting methods, it can seem like a fast track to results.
The Initial Success: Losing 5 Kg in a Month
In this case, the woman had been struggling with stagnant weight and belly fat, despite eating healthfully and working out consistently. After researching online testimonials and fasting protocols, she decided to implement 36-hour fasts twice per week.
Within one month, she lost five kilograms. Her energy levels initially soared, sugar cravings disappeared, and her stomach appeared visibly flatter. She reported clearer skin and improved focus. The progress seemed promising, and the method appeared to be working well—until subtle health issues began to appear.
The Hidden Side Effects of Prolonged Fasting
While her weight dropped, her overall wellbeing started to suffer. By the end of the fourth week, she was grappling with three significant issues that she hadn’t experienced before.
1. Bloating After Meals
Despite eating healthy foods and breaking her fast gently with light meals, she experienced intense bloating and abdominal discomfort.
This is a common side effect of prolonged fasting. Extended periods without food can lead to a decline in digestive enzyme production and changes in gut bacteria. When food is reintroduced, the digestive system may not be ready, leading to gas, bloating, and discomfort even with small or simple meals.
2. Acidity and Heartburn
Another concern that arose was persistent acidity, especially during the nights following fasting days.
Prolonged fasting increases the production of stomach acid. Without food to absorb this acid, it can irritate the stomach lining and esophagus, leading to symptoms of acid reflux or heartburn. Additionally, stimulants like black coffee, often consumed during fasting periods to suppress appetite, can worsen this irritation.
3. Insomnia and Restless Sleep
Perhaps the most surprising side effect was the onset of insomnia. Despite physical tiredness, she found herself struggling to fall asleep and waking up frequently during the night.
Extended fasting can cause fluctuations in blood sugar and an increase in stress hormones like cortisol. When blood sugar drops too low during the night, it can trigger an alert response in the brain, making restful sleep difficult. The disruption in circadian rhythm due to irregular eating patterns can further complicate sleep quality.
What Health Experts Say
Nutritionists and medical professionals generally agree that intermittent fasting, when done correctly, can have numerous health benefits. However, longer fasts like the 36-hour method are not suitable for everyone and carry certain risks if not managed properly.
According to Dr. Neha Sharma, a clinical dietitian and wellness consultant:
“Fasting should support your health, not compromise it. While extended fasting can encourage fat burning and metabolic changes, it also puts the body under stress. For some people, especially women, this can impact hormones, digestion, and sleep. It’s essential to understand your body’s signals and adjust accordingly.”
Many health experts recommend starting with shorter fasting windows, such as 14:10 or 16:8, before attempting longer fasts. Individuals with medical conditions, those who are pregnant or breastfeeding, or those with a history of eating disorders should avoid extreme fasting protocols unless under medical supervision.
How to Minimize Side Effects of Fasting
If you’re considering a 36-hour fast, it’s important to follow some best practices to protect your overall health:
Start Gradually
Begin with shorter fasting windows and observe how your body responds before transitioning to longer fasts.
Hydration is Key
Drink sufficient water throughout your fasting window. Avoid excessive caffeine or acidic beverages like black coffee and tea, especially if you’re prone to acidity.
Break Your Fast Gently
Do not overeat or break your fast with high-fat, high-carb, or spicy foods. Begin with broth, steamed vegetables, or a small portion of protein.
Monitor Your Sleep and Stress Levels
If you notice sleep disruption, mood swings, or fatigue, these are signs your body may be under stress. Consider reducing the frequency or length of your fasts.
Support Your Gut
Incorporate gut-friendly foods like yogurt, fermented vegetables, and fiber on eating days to maintain digestive balance.
What She Learned From the Experience
Though the weight loss was a short-term success, the side effects prompted her to rethink her approach. She has now shifted to a gentler 16:8 intermittent fasting schedule, which allows her to maintain a healthy routine without the digestive and sleep-related issues she experienced earlier.
Her new focus is on sustainable habits, gut health, and consistent sleep patterns rather than chasing rapid results. “Fasting taught me discipline and helped me understand my relationship with food. But I also learned that more extreme doesn’t always mean more effective. Health should feel good—not exhausting.”
The Real Cost of Rapid Weight Loss
The story of losing 5 kg in a month through 36-hour fasting may sound impressive, but the accompanying issues of bloating, acidity, and insomnia are important reminders that weight loss is not just about numbers on a scale. Sustainable health is about balance, nourishment, and listening to the body’s signals.
For those considering prolonged fasting, it is crucial to weigh the pros and cons, start slowly, and consult a healthcare provider if needed. A leaner body should not come at the expense of gut health, sleep, or overall well-being.
