Data usually come from observational studies on hunger strikes and periods of famine. In this article, learn more about the factors that affect how long a person can survive without food and water. A typical, well-nourished male weighing 70 kilograms pounds technically has enough calories stored to survive for between 1 and 3 months. However, people who have voluntarily stopped eating to participate in hunger strikes have died after 45—61 days , which suggests that a person would be unlikely to survive for 3 months.
The body needs the nutrients in food to survive. It uses protein, carbohydrates , and fats, as well as vitamins and minerals, to renew cells and fuel vital bodily processes.
Without food, the body starts to use its own tissue as fuel, but it can only do this for so long. Scientists are not sure exactly how long the average person can go without food. They have not studied starvation in traditional experiments because it would be unethical to ask a person not to eat for a prolonged period in order to examine the outcome.
The best indication that researchers have of how long people can survive comes from those who have been on hunger strike. Many factors can affect how long a person can go without food. The amount of liquid that the person drinks will also be significant. Experts believe that sipping water from early on in the period without food may prolong survival. To compensate for the lack of food, the body breaks down its own tissue to use as fuel. This process may involve muscle tissue, including that of the heart.
The pulse and blood pressure drop because the heart does not have the fuel that it needs to pump blood around the body as effectively as normal. This inefficient pumping can lead to heart failure. Food restriction interferes with how the stomach digests food and empties itself.
It can lead to:. After a few days, your energy levels will decrease, and you will become less mentally alert and sleepier. Most people begin to go in and out of consciousness by the third day and later become unarousable. Since dehydration will most likely be the cause of death, it is important not to drink anything once you start. Even sips of water may prolong the dying process. We recommend that all medications be stopped except for those for pain or other discomfort.
Stopping medications for heart problems or diabetes, for example, may speed up the process. Note: With the exception of quotes, information in the following sections has been adopted from End of Life Washington. For some people with terminal illness, aggressive medical treatment may not be helpful and may prolong the dying process without improving quality of life.
Under certain circumstances, treatments can increase suffering, ruin the remaining quality of life, or even shorten life. Stopping treatment can result in a peaceful death, but it may also result in increased discomfort. Consult with your physician and arrange for optimal palliative comfort care before stopping treatment.
Stopping treatment can be combined with hospice and palliative care or voluntarily stopping eating and drinking to shorten the dying process and reduce suffering.
Palliative sedation provides enough medication to keep patients with terminal illness in excruciating pain continuously unconscious and thereby free of pain and symptoms. All nutrition and hydration is stopped, and they usually die within a few days. People using palliative sedation should be monitored around the clock to be sure the sedation is adequate. Clin Med Insights Case Rep. Arch Kriminol. Women live longer than men even during severe famines and epidemics. Patterns of frailty in non-adults from medieval London.
Int J Paleopathol. Mehler P. Updated February Anorexia nervosa in adults and adolescents: Medical complications and their management. The effect of prolonged fasting on levels of growth hormone-binding protein and free growth hormone. Michigan Health. Published July 29, Quill, T. Your Privacy Rights. To change or withdraw your consent choices for VerywellHealth. At any time, you can update your settings through the "EU Privacy" link at the bottom of any page. These choices will be signaled globally to our partners and will not affect browsing data.
We and our partners process data to: Actively scan device characteristics for identification. I Accept Show Purposes. Can an obese person go without food longer than a normal-weight person? When will I start burning fat if I stop eating? The body's ability to alter its metabolism is poorly understood, but it occurs at least in part through changes in thyroid function. This may help explain the evolutionary persistence of genes causing diabetes, which in the past could have allowed individuals to survive periods of starvation by enabling more economical use of energy.
Medical practitioners encounter cases of near-total starvation in patients suffering from, among other conditions, anorexia nervosa and end-stage malignancies, as well as in those following so-called starvation diets. In anorexia, death from organ failure or myocardial infarction is fairly common up to 20 percent of cases end this way and tends to happen when body weight has fallen to between 60 and 80 pounds although it can occur at any time. This weight typically corresponds to a body mass index BMI approximately half of normal, or about 12 to Normal BMI is Unless other causes intervene, a patient with end-stage cancer often dies after losing 35 to 45 percent of his body weight.
Markedly obese patients on near-starvation diets, such as those employing nutritional supplements and consuming less than calories a day, may lose much more weight than that--but they start with great excesses of body fat, which can sustain metabolism.
The medical community has generally rejected these diets, which were popular in the s and s, because participants were reportedly prone to acute myocardial infarctions. I recall one particularly relevant experience that illustrates the inherent variability in people's ability to survive on very little food.
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