The length of time a person can survive without eating depends on various factors such as age, body weight, overall health, and access to water. Generally, if a person has access to water, they can survive for about two to three months without food. This is because the body initially uses glucose reserves, then shifts to burning fat and producing ketones for energy, and finally breaks down muscle protein once fat stores are depleted
. Without water, survival time is much shorter-typically only about 3 to 5 days-because dehydration leads to organ failure much faster than starvation alone
. Here is a summary timeline of what happens when you don’t eat but have water:
- Within 24 hours: The body uses up glucose and glycogen stores.
- After 2-3 days: The body begins breaking down fat for energy, producing ketones for the brain.
- After about a week: Muscle protein breakdown increases as fat stores diminish.
- Beyond several weeks: Continued muscle loss can impair vital organs and lead to death
In rare cases, some individuals have survived up to 40 days without food, but this is exceptional and depends heavily on individual conditions
. In summary:
- With water: Survival can be up to 2-3 months without food.
- Without water: Survival is limited to about 3-5 days.
- Starvation leads to progressive use of energy stores-glucose, fat, then muscle-ultimately causing organ failure if prolonged
