Tag: Overnight fast

While you sleep, your brain’s high glucose demand drains your liver glycogen stores, leading to a 60-80% overnight depletion. This answers the question of how much glycogen do you lose overnight and reveals a critical metabolic process that sustains your body’s most vital organ during your nightly fast.

During a typical overnight fast, the liver's glycogen stores can be depleted by as much as 70-80%, dropping from approximately 90-100g to 20-30g to fuel the brain and other vital organs. This process is the primary way your body maintains stable blood sugar levels during sleep.