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How long can a human stop eating?

Humans need food to survive. Food provides the body with essential nutrients that are necessary for energy, growth and maintaining health. However, the human body has evolved remarkable mechanisms to keep functioning even during periods of insufficient food intake. So how long can a person actually survive without any food?

Key Factors That Determine Survival Time Without Food

There are several key factors that impact how long someone can survive without eating food:

– Metabolism – The basal metabolic rate (BMR) determines how many calories your body burns at rest to maintain basic physiological functions. A slower metabolism means the body uses less energy and can survive longer without food. Age, gender, genetics, body size and composition affect BMR.

– Fat stores – Body fat provides an internal food reserve. The more body fat a person has, the longer they can survive without eating as the body breaks down fat stores for energy. Men with more muscle mass tend to survive longer than women.

– Hydration – Water is critical for survival. Dehydration will hasten death in the absence of food. Access to water can actually prolong survival more than food reserves alone.

– Activity level – The more active someone is, the more energy their body requires and the faster their reserves will become depleted without food intake. Physical rest and sleep increase survival time.

– Climate conditions – Colder environments lead to faster depletion of energy reserves and shorter survival compared to warmer climates. Exposure and freezing temperatures rapidly consume calories.

– Individual health – Age, underlying health conditions, illness or disease affect the body’s ability to cope without food. Healthy adults can survive longer without eating than children, elderly and sick individuals.

– Mental fortitude – The will to live and mental attitude impacts survival capacity. Giving up and losing the motivation to keep going will shorten survival time.

Metabolic Changes When Fasting

During prolonged periods without food intake, the body goes through a series of metabolic adaptations in an effort to spare protein reserves and prolong survival.

In the first 12-24 hours of fasting, the body relies on immediate blood glucose and stored liver glycogen for energy. Glycogen reserves last for about 24 hours before being depleted.

As fasting continues, the body stimulates gluconeogenesis, which generates glucose from non-carbohydrate sources like amino acids, glycerol and lactate. Endogenous glucose production helps maintain blood sugar levels.

The body increasingly relies on fat metabolism for energy after 1-3 days of fasting. Ketone bodies produced from breaking down fat become the primary fuel source. This protein-sparing metabolic shift prolongs survival time.

Starvation mode is triggered after several days of fasting. The body decreases BMR and suppresses metabolism by up to 50% in an attempt to conserve energy and vital proteins. Physical and mental activity is reduced.

After 3 or more weeks of starvation, critical protein loss and atrophy of organs like the heart and liver eventually lead to death. The specific time to death varies based on the factors discussed earlier.

How Long Can You Survive without Food and Water?

Water is essential for survival and can hasten or prolong the time until death when fasting. Here is how long someone may survive without food and water:

– 3 to 5 days without water – Dehydration rapidly leads to death in as little as 3 days for a healthy person. Drinking water will prolong survival, even without food.

– 7 to 14 days without food – A healthy, well-hydrated adult can typically survive for 2 to 4 weeks without food depending on fat reserves. Water intake is critical.

– Up to 21 days without food – Documented cases of prolonged starvation have found survival for 17 to 21 days or longer is possible for obese individuals who still have access to water.

– 30 to 70 days with limited food and water – With a very small amount of daily food intake such as 200 to 500 calories and limited water, survival may reach 70 days in exceptional cases.

– 6 to 8 weeks for an overweight person with no food but available water – People carrying substantial fat can survive 1 to 2 months without food if they remain adequately hydrated.

Prolonged fasting beyond 3 or 4 weeks without any nutrition leads to muscle wasting, organ failure and eventually death. Access to at least some water can extend survival by several days or weeks depending on the individual.

World Records for Surviving without Food

There are some incredible documented examples of people surviving months without food due to forced hunger strikes, being lost at sea or trapped after disasters. These are the longest recorded survival times without any food intake:

– 74 days – an Indian man survived 74 days of monitored fasting under medical supervision during an experiment in 1963. He was given supplements and remained active.

– 18 months – Angus Barbieri fasted for 382 days straight in Scotland in 1966. He lived on tea, coffee, soda water and vitamins while losing 276 pounds and remained healthy.

– 147 days – In 1973, Dennis Galer Goodwin survived on water alone for 147 days to assert his innocence of a rape conviction. He lost 154 pounds.

– 76 days – In 1981, IRA prisoner Bobby Sands starved for 66 days during his hunger strike and died. Fellow prisoner Francis Hughes survived without food for 76 days before dying.

– 3 months – In 2010, a North Korean seal hunter survived being adrift for over 3 months in freezing temperatures and rough seas by catching fish, birds, and turtles and drinking rainwater.

However, these world records represent extremes of prolonged fasting under special circumstances. Most healthy adults would be unable to survive past 4-8 weeks without any nutrition before organ failure and death occurs.

Survival Timeline Without Food

Here is an approximate timeline for how long a healthy, well-hydrated adult may expect to survive without any food based on medical case reports and survival studies:

Time after last meal Effects
12-24 hours Glycogen reserves used up. Mild ketosis begins.
48-72 hours Gluconeogenesis maintains blood glucose. Ketosis increases. Appetite diminishes.
4-7 days Metabolism slows by up to 50%. Ketone bodies replace glucose as primary fuel.
2-4 weeks Prolonged starvation adaptation. Diminished organ function. Muscle wasting begins.
8-12 weeks Increasing weakness and organ failure. Daily activity difficult. Death from heart failure likely.

As you can see, based on metabolism and available energy stores, a healthy adult is estimated to be able to survive without any food intake for approximately:

– 2 to 4 weeks – normal survival time based on body reserves
– 8 to 12 weeks – extreme survival time before organ failure results in death

The maximum duration will vary depending on the individual factors discussed earlier. Access to water can extend this by a few days or weeks. Beyond 2 to 3 months of fasting is life-threatening for even a healthy person.

Can You Go Longer than 3 Months without Food?

Surviving more than 3 months without any nutrition at all is extremely rare. There are a few exceptional recorded cases of prolonged starvation extending this duration:

– Fasting girls – Some young women in the 1800s publicly claimed to survive for 6 to 24 months without eating due to religious fasting or supernatural causes. Most were found to be secretly eating, although two claims were considered credible.

– Prahlad Jani – Claims to have lived 70 years without food, sustaining himself through spiritual practices. Scientific studies found he survived 15 days under observation without eating but likely secretly ate at other times.

– Angus Barbieri – Fastest medically confirmed survival fast, lasting 382 days straight while taking vitamin supplements in Scotland in 1966. He remained healthy after fasting for over a year.

While a handful of extraordinary claims or circumstances exist, most doctors agree survival beyond 2 to 4 months is not possible for a normal healthy adult. Even obese individuals with substantial fat stores tend to succumb after 70 days or less due to protein deficiency and organ failure.

Why Claims of Extreme Fasting are Usually Misleading

There are several reasons why many accounts of individuals surviving 6 months or longer without any food at all are dubious or exaggerated:

– Secrecy – Claims made publicly but details of supervision and documentation are not verified.

– Misrepresentation – Food is secretly eaten at times to prolong survival.

– Supplementation – Use of vitamins, electrolytes, yeast, honey or other forms of nourishment supplement fasting.

– Activity level – Complete physical rest minimizes calorie expenditure versus normal daily activities.

– Individual factors – Youth, female gender, obesity support longer fasting periods in some unique cases.

– Origin of claims – Stories originate long ago or from spiritual contexts without scientific basis.

While exact recorded limits of fasting duration vary, most medical evidence strongly indicates survival beyond around 70 days without any nutrition at all is essentially impossible for a normal healthy adult.

Prolonged Fasting with Limited Food Intake

In documented cases of long-term starvation extending 60 to 80 days, some minimal food intake is almost always present to prolong survival.

Consuming even 100 to 500 calories daily in the form of non-nutritious foods, juices, milk, honey, yeast, vitamins or nutrition supplements can extend survival by weeks compared to a total fast.

For example, Mahatma Gandhi survived 21 days of fasting by taking sips of water, citrus juice, and sodium bicarbonate daily. With traces of daily sustenance, survival can exceed what is possible with no food at all. However, complete fasting leads to death within 8 to 12 weeks typically.

Impact of Limited Food Intake on Prolonged Fasting

During prolonged starvation, even small amounts of certain nutrients and calories can provide advantages:

– Carbohydrates – About 100-200 calories of simple sugars maintains blood glucose levels longer.

– Protein – 10-20 grams of protein may delay muscle wasting and vital protein loss.

– Fats – Small amounts of healthy fats help sustain metabolism and energy levels.

– Vitamins – A basic multivitamin or electrolytes prevent nutritional deficiency.

– Fluids – Water, juice, broth prevent deadly dehydration.

– Fiber – Indigestible fiber provides bowel regularity.

– Calories – 100 to 500 calories a day extends survival by supplying basic fuel for the body.

While not fully nutrition-adequate, traces of nourishment during extended fasting can enable survival beyond the typical limits of complete starvation. However, long-term health consequences may still result.

How Long Can You Survive without Food and Water?

Lacking both food and water leads to death much faster than starvation alone. Here is an overview of survival time without either food or water:

– 3 days max – Most adults will die after 72 hours without fluids due to dehydration.

– 5 to 7 days – With limited physical activity in temperate conditions or some moisture intake like rainwater, survival may reach 5 to 7 days.

– 10 days – Near the absolute limit for humans without water intake. Certain conditions like shelter and cooler climates may prolong this by 1 to 2 days at most.

– No more than 14 days even under optimal conditions – Claims of surviving weeks without any water at all are considered medically impossible.

Going without either food or water for even a few days has severe health consequences and can quickly become deadly. Seek medical care immediately if you experience prolonged food and water deprivation for over 48 hours.

Physiological Effects of Dehydration

Dehydration progresses rapidly without fluids and leads to potentially fatal outcomes like:

– Thirst and dry mouth – Begins around 1% dehydration

– Dizziness and fainting – Results from low blood volume and pressure

– Reduced urine output – Body tries to conserve water

– Rapid breathing, heartbeat and confusion – As dehydration worsens over 5%

– Swollen tongue and inability to swallow – Around 10% dehydration

– Shriveled skin, seizures and coma – Once dehydration exceeds 15%

– Hypovolemic shock, organ failure and death – Above 20% dehydration

Losing over 10% of the body’s water leads to severe and life-threatening complications. Death occurs when dehydration exceeds 20% fluid loss in most cases.

Survival Timeline Without Food or Water

Here is a typical estimated timeline for how long someone may survive without either food or water before death:

Time Condition and survival outlook
24-48 hours Thirst, headache, fatigue, dizziness. Good chance of survival still.
3 days Weakness, difficulty standing, labored breathing, tingling limbs. Survival still likely if hydration is provided.
4-5 days Impaired organ function, sunken eyes, low blood pressure, heart arrhythmias. At high risk of death without fluids.
6-7 days Hallucinations, vision loss, shriveled skin, seizure, coma, kidney failure. Near certain death soon without hydration.
8+ days Circulatory collapse, convulsions, respiratory arrest, brain death. Survival past this point is essentially impossible.

As dehydration worsens, the risk of death rises rapidly. Most healthy adults cannot survive longer than 7-10 days at most without any fluid intake depending on environmental conditions. Lack of food accelerates the timeline and likelihood of a fatal outcome without water.

Can You Die from Not Eating for 2 Weeks?

Complete starvation for 14 days is unlikely to directly cause death in otherwise healthy adults who are receiving adequate hydration. However, severe health impacts result from fasting for this duration.

Potential dangers and complications arising after 2 weeks without food include:

– Dangerously low nutrient reserves – Depleted electrolytes, vitamins and minerals

– Muscle wasting – Up to 20% loss of lean muscle mass

– Organ stress – Heart and kidney function decline, liver size reduces

– Severe ketosis – Ketone buildup leading to ketoacidosis risk

– Immune suppression – Increased infections and infectious disease risk

– Low blood sugar – Increased risk of hypoglycemia with exertion

– Orthostatic hypotension – Blood pressure drop upon standing

– Impaired concentration and cognition – Confusion, loss of alertness and mental deficits

– Micronutrient deficiencies – Anemia, osteoporosis, scurvy

– Psychological issues – Depression, anxiety, body image disorders

Without nutrition, the body begins breaking down vital proteins and muscle tissue to provide energy by 2 weeks, entering a starvation state. Continuing this extreme fast leads to wasting, organ failure and eventual death, even if hydration is maintained.

Health Risks at 2 Weeks Fasting

While not acutely life-threatening at 2 weeks, concerning health risks appearing at this stage include:

– Infection – Loss of immune function and white blood cell counts

– Refeeding syndrome – Metabolic shifts and heart failure risk with reintroducing food

– Thiamine deficiency – Beriberi disease affecting nerves and heart

– Hypokalemia – Muscle cramps, weakness, ECG changes from potassium loss

– Hypophosphatemia – Bone health, cell function, and respiration impairment

Without prompt nutritional support, these risks can worsen rapidly at 2 weeks, making death likely by 4 weeks even with hydration. However, recovery is still possible at this stage with medical intervention and refeeding.


In summary, a healthy well-hydrated adult can typically only survive without any food intake for:

– 2-4 weeks before organ failure results in death

– In exceptional cases, obese persons have survived up to 70 days fasting

– Survival beyond 3 months without food is extremely rare

– Dehydration becomes deadly after only 3 to 7 days without water

– Traces of nutrition may prolong survival a few extra weeks

– Fasting for just 2 weeks has severe health consequences

While the human body has remarkable abilities to sustain itself through fasting, complete starvation extends the limits to between 8 and 12 weeks at most. Water intake is absolutely vital for survival past several days without food. Claims of living months or years without eating are medically implausible and likely false. Prompt intervention for renutrition and hydration is crucial after more than 2 weeks of starvation to avoid the risk of permanent effects or death.