Fasting for 36 hours has become a popular trend online, often promoted as a “reset” for the body. The basic idea is that when you stop eating, your body first uses stored sugar (glucose) for energy, then begins tapping into stored glycogen, and eventually shifts toward burning more fat for fuel. Supporters also talk about processes like ketosis and autophagy—natural metabolic and cellular cleanup functions that may increase when the body has fewer incoming nutrients. Some people report feeling clearer or lighter during longer fasts, but experiences vary widely, and the science isn’t as simple as many viral videos make it sound.

At the same time, extended fasting can carry real risks—especially if someone has certain health conditions, a history of disordered eating, low blood pressure, diabetes, or is pregnant, or if they take medications that affect blood sugar, blood pressure, or inflammation. Possible downsides include dizziness, headaches, low energy, irritability, dehydration, electrolyte imbalance, and trouble concentrating, and for some people it can trigger unhealthy cycles with food. If someone wants to try fasting, the safest approach is to start gently, focus on hydration, prioritize sleep, and talk with a qualified healthcare professional—particularly before attempting longer fasts. The most reliable “reset” is still the basics done consistently: balanced meals, enough sleep, regular movement, and sustainable habits that support health long-term.