Predict the exact hours when your body transitions into glycogen depletion, heavy fat-burning ketosis, peak growth hormone (HGH), and deep cellular autophagy renewal.
Get real-time alerts when your cells reach Ketosis, HGH Surge, and Autophagy Peak with our free Fasting Tracker app.
Get Free Fasting Tracker App →Autophagy (from Greek meaning "self-eating") is the natural physiological mechanism where cells disassemble and remove dysfunctional components and damaged organelles. Awarded the 2016 Nobel Prize in Medicine, it is nature's ultimate longevity and anti-aging repair process.
| Hour Range | Biological Phase | Dominant Fuel Source | Key Physiological Shift |
|---|---|---|---|
| 0 – 4h | Anabolic / Digesting | Exogenous Glucose | Insulin rises; glucose is absorbed and stored as glycogen. |
| 4 – 12h | Post-Absorptive | Liver Glycogen | Insulin drops; digestive system rests; glucagon secretes. |
| 12 – 16h | Early Ketosis | Free Fatty Acids | Glycogen depletes; liver converts fatty acids into ketones. |
| 16 – 24h | Autophagy Initiation | Ketones (BHB/AcAc) | HGH surges +300%; cellular lysosomal recycling begins. |
| 24 – 48h | Peak Autophagy | Deep Ketosis | Systemic inflammatory cytokines drop; stem cells refresh. |
No! Plain black coffee and unsweetened green tea contain polyphenols (like EGCG) that actually stimulate AMPK and enhance cellular autophagy.
Direct autophagy requires tissue biopsy, but blood ketone levels (beta-hydroxybutyrate) above 1.0 mmol/L serve as a clinically proven surrogate marker.
Cellular autophagy accelerates after 16 to 18 hours of fasting, reaching peak rates between hours 24 and 48.
