Fasting Tracker
Input your last meal time to start the metabolic clock.
How your body switches fuel sources
This loop represents the metabolic switch. When you stop eating, your body eventually exhausts glycogen stores. Without dietary glucose, insulin stays low, signaling the liver to break down fat into ketones—the brain's preferred, high-efficiency fuel.
Visceral fat (the "hidden" fat around your organs) is highly metabolically active and inflammatory. Research suggests that intermittent and prolonged fasting are particularly effective at targeting this specific fat type. By maintaining low insulin levels, you force the body to mobilize these deep energy stores, reducing the risk of fatty liver and metabolic diseases.
Dr. Jason Fung highlights that fasting's magic lies in the hormonal shift. As insulin drops below a critical threshold, the body accesses deep fat stores and reverses the pathology of Type 2 Diabetes.
Dr. Eric Berg notes that by the 72-96 hour mark, the body breaks down old white blood cells, triggering stem cells to regenerate a new immune system upon refeeding.
Prolonged fasting improves memory and cognitive function by increasing BDNF, protecting neurons from age-related degradation and providing significant mental clarity.