A fascinating YouTube simulation illustrating the effects of fasting on the body has gone viral—but not all health experts are convinced.
People fast for various reasons, from religious practices to weight loss and even mental clarity. While going without food for extended periods may sound extreme to some, others swear by its benefits and incorporate it into their routines.
According to *Medical News Today*, fasting—when done safely—can help regulate blood sugar and improve insulin sensitivity. However, it’s not suitable for everyone, and consulting a healthcare professional before starting is highly recommended.
For those curious about the process, a popular YouTube video breaks down exactly what happens during a 36-hour fast—and the results are surprising.
### **What Happens to Your Body During a 36-Hour Fast?**
#### **4 Hours In**
After four hours without food, your body stops digesting and enters the *catabolic phase*. According to Dr. Kiltz, this is when stored energy molecules break down to fuel your cells.
#### **8 Hours In**
Blood sugar levels drop, and your body begins burning stored glycogen (energy reserves) instead of relying on incoming food.
#### **12 Hours In**
With glucose depleted, your liver starts converting fat into fatty acids called *ketones*. This process, known as *metabolic switching*, is why fasting can lead to weight loss (*BBC*).
#### **16 Hours In**
A crucial cellular cleanup called *autophagy* begins. Damaged cell parts are recycled into new, functional ones (*Cleveland Clinic*). Dr. Kiltz notes that exercise can enhance this process, while disruptions may lead to abnormal cell growth.
#### **24 Hours In**
At this point, your body is in full fat-burning mode, reducing inflammation and improving insulin sensitivity.
#### **30 Hours In**
Growth hormone levels spike, helping preserve muscle while promoting fat loss. The video also claims this is when *deep healing* begins.
#### **36 Hours In**
Autophagy peaks, accelerating tissue regeneration and metabolism. Some extend this reset for up to 72 hours.
### **What Do Experts Say About Fasting?**
Opinions are mixed. While some praise its benefits, others highlight a lack of long-term human studies.
James Betts, a metabolic physiology professor at the University of Bath, told *The Guardian*:
*"There are a lot of proposed benefits, but much of the research hasn’t been conclusively proven in humans. Dramatic short-term health benefits aren’t always evident."*
Potential risks include gallstones (*News in Health*), intense hunger, digestive issues, and mood swings. However, Johns Hopkins neuroscientist Mark Mattson argues fasting may protect against chronic diseases like diabetes, heart disease, and even cancer.
**Final Note:** Since everyone responds differently, always consult a doctor before trying prolonged fasting.
