A person can survive without food for about 3 weeks to 2 months, depending heavily on individual factors such as body fat reserves, overall health, hydration, and environment. However, survival without water is much shorter, usually only 3 to 5 days. The body adjusts by using stored energy reserves, first burning glycogen, then fat, and finally muscle tissue if starvation continues. Severe complications and death usually occur once muscle mass and organ functions degrade significantly due to prolonged starvation.

Survival Time Without Food

• Typical survival without food but with water is up to 3 weeks.
• Some rare cases show survival up to 2 months or even more under medical supervision or special conditions.
• The availability of water greatly extends the survival time compared to total starvation (no food and no water).

Body's Response to Starvation

• Initially uses glucose stored as glycogen.
• Shifts to fat metabolism producing ketones for energy.
• Breaks down muscle tissue as a last energy source, which leads to organ failure and death if starvation persists.

Influencing Factors

• Body weight and fat stores: More fat can prolong survival.
• Hydration: Drinking water increases survival time significantly.
• Health conditions, age, and activity level: Affect how quickly the body uses energy reserves.
• Environmental conditions such as temperature also play a role in survival duration.

These survival times are based on observational studies such as hunger strikes and famine cases, as deliberate starvation studies are unethical.