How Long Can You Survive Without Eating? The Surprising Truth Revealed

Eating is not just something we do to satisfy our hunger. Instead, it is a necessary activity that the body requires to keep functioning properly. However, in certain circumstances, starvation becomes inevitable, and one might wonder how long they can survive without eating. This article looks at various aspects related to this question, including the science behind the body’s ability to withstand starvation, the impact of dehydration on survival, and tips for surviving without food.

The Human Body and Starvation

The human body is a remarkable organism with the ability to adapt to various conditions, including food scarcity. When the body extensively burns glycogen and glucose stored in the liver and muscles, it begins to break down fats, which the liver converts into ketone bodies to provide energy for the brain and other body functions. This mechanism enables the body to survive for an extended period without food, but the timing varies and depends on numerous factors.

The Factors that Influence Survival

  • Age: Infants and elderly persons are particularly sensitive to starvation and may not survive as long as young adults.
  • Gender: Women tend to have more body fat than men, an important energy reserve when food is scarce.
  • Health Status: Individuals with pre-existing medical conditions may not survive as long as healthy persons.
  • Body Weight: A person’s mass largely determines the length of time they can survive without food. A higher weight means an individual has more reserves to depend on.
  • Level of Hydration: Dehydration is a significant risk when calories are not available, and moderate to severe dehydration can cause organ failure or even death.

It is critical to note that the rate at which an individual loses weight significantly affects their survival. Studies show that an average person requires approximately 1200 to 1500 calories per day to maintain body weight. When an individual in a resting state (no physical activity) does not eat, their body starts burning up to 100 calories a day, and the rate increases the longer they continue with the fast.

How Long can you Survive Without Food?

Survival Period without Food

The duration that the body can survive without food varies and depends on the medical history, gender, and the presence of any underlying health conditions.

Type of Fasting Duration
Water Fasting 7-14 Days
Juice Fasting 30-40 Days
Complete Fast (water only) 35-40 Days
Partial Fast (liquids, fruits, and vegetables) 21-30 Days

These are general guidelines, and individuals may have different experiences depending on their body composition and medical history. Those who are obese may survive in a fasting state for longer periods because of the energy reserves in their bodies. On the other hand, individuals with fewer reserves may struggle from early signs of starvation as early as day 3 without food.

Early signs of Starvation

When the body is deprived of food for an extended time, it may show various signs of starvation, including:

  • Muscle weakness, dizziness and fatigue
  • Headache
  • Loss of body weight
  • Irritability and mood swings
  • Low blood pressure and body temperature
  • Decreased immune function
  • Poor concentration and cognitive function.

Dehydration and its impact on Survival

Effects of dehydration on the body

Dehydration occurs when the body is losing water at a faster rate than it is replenished through fluids. Water plays a crucial role in almost all body processes and is vital in maintaining optimal health. Loss of fluids through sweating, diarrhea, vomiting, or increased urine output can lead to dehydration, which can have severe consequences in a starvation state.

Early signs of dehydration include thirst, dark colored urine, dryness of skin, and a dry mouth. Severe dehydration can lead to symptoms such as irritability, sunken eyes, increased heart rate, and even seizures.

Dehydration and Its impact on survival time

The presence of water in the body plays a crucial role in survival during a period of food scarcity. The body can survive for several weeks without food, but the duration reduces significantly in the presence of dehydration. Mild-to-moderate dehydration can cause organ failure, and severe dehydration can result in death. Typically, it takes three to four days without water to cause death, but factors such as age, weight, and environmental conditions can accelerate this timeline.

Tips for surviving without food


Ensuring adequate and consistent hydration during a period of food scarcity is critical. Drinking water or fluids helps maintain the fluid balance in the body and prevent dehydration, which can accelerate the onset of starvation.

Slow and Steady

While it is possible to live for weeks without food, it is always advisable to take the process slow and steady. For example, Intermittent fasting, such as skipping meals, is a healthier approach compared to prolonged fasting.

Seek Medical Attention

Medical supervision is critical during a period of food scarcity. A physician can help monitor an individual’s body composition, assess vital signs, and provide appropriate interventions to prevent complications or adverse effects.

Seek Support

Support from family and friends is critical during difficult situations such as starvation. Friends can help provide moral support, reduce stress levels and prevent boredom, which can be a significant challenge during prolonged fasting.

Common Questions and Answers

How long can you survive without food as an obese person?

Obese individuals have more body fat reserves, which they can rely on during a period of food scarcity. Depending on preexisting medical conditions, they can go without food for around 50 to 70 days.

Can you prolong starvation by sleeping?

Sleeping cannot prolong starvation since the energy required to maintain body functions is still necessary during sleep. However, sleeping may prevent an individual from feeling hungry, but it does not reduce the body’s energy needs.

Can you live without food and water?

No, an individual cannot live without water. Severe dehydration leads to complications such as organ failure, and death may occur after only three to four days without water.


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  • Berglund, E. D. (2019). The role of ketone bodies in the physiology and pathology of the nervous system. Basic & clinical pharmacology & toxicology, 125(4), 352-359.
  • Hattad, T. A., & Ali, N. A. (2020). Dehydration. StatPearls. Treasure Island, Florida: StatPearls Publishing.
  • Johnstone, A. (2015). Fasting for weight loss: an effective strategy or latest dieting trend? International journal of obesity (2005), 39(5), 727-733.
  • Kleinman, R. E., & Sandman, C. A. (1981). Starvation, stress, and neuroscience: the role of glucocorticoids. Physiology & behavior, 26(2), 215-221.

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