What happens to your body during an 18-day fast?A day-by-day look at how your body survives without food.
Day 1-2 The body uses stored sugar.Glucose is used first for energy.Then glycogen stored in the liver and muscles is broken down.Hunger is usually strongest during this phase.
Day 3-7The body switches to fat.Fat becomes the main energy source.The liver produces ketones to fuel the brain.This helps preserve muscle in the early stages.
Why hunger decreases?Hormones like ghrelin and leptin change.Appetite gradually fades.Weakness replaces hungeras the dominant symptom.
Week 2- Energy levels drop.Walking and climbing stairs become difficult.Blood pressure and heart rate slow.Hands and feet may feel cold due to reduced circulation.
Around day 18, the critical phase beginsFat reserves start running low.The body begins breaking down muscle for energy.Even the heart, which is a muscle, can eventually be affected.
Organs under strainHeart function may weaken.Kidneys and liver face increasing stress.Risk of dizziness, fainting and organ dysfunction rises.
Electrolyte deficiencies can cause irregular heartbeat, seizures, or kidney injury.Vitamin deficiencies weaken immunity, muscles and brain function.Water and salt alone cannot provide essential nutrients.
Breaking the fast needs medical care.Eating normally after a long fast can trigger refeeding syndrome.