What is the longest anybody has gone without food?

November 28, 2025 •

4 min read

In 1965, a Scottish man named Angus Barbieri, weighing 456 pounds, began a medically supervised fast that would ultimately set the world record for what is the longest anybody has gone without food, lasting an astonishing 382 days. This remarkable case offers a rare glimpse into the human body's physiological adaptations to prolonged nutrient deprivation, though it was an extreme and dangerous undertaking.

Quick Summary

The world record for the longest supervised fast was set in 1965 by Angus Barbieri, who went 382 days without solid food to lose a dramatic amount of weight. His incredible feat, managed under strict medical observation, demonstrated the body's metabolic adaptations to extreme conditions, primarily using fat reserves for energy.

Key Points

Longest Documented Fast: Angus Barbieri, a Scottish man, survived a medically supervised fast of 382 days without solid food in 1965–1966.
Survival Factors: Barbieri's ability to fast for so long was heavily dependent on his starting weight of 456 pounds and constant medical oversight, including vitamin and electrolyte supplements.
Metabolic Shift: During prolonged fasting, the body first burns glucose, then switches to burning its fat reserves for energy through a process called ketosis to conserve muscle tissue.
Dangerous Undertaking: Despite Barbieri's success, extreme prolonged fasting is exceptionally dangerous and can lead to severe health complications, including heart failure and death, especially without medical supervision.
Ethical Concerns: Guinness World Records no longer sanctions or encourages fasting records due to the significant health risks involved.
Long-Term Health: Five years after his fast, a study showed that Barbieri had maintained his weight loss with no ill-effects, though this outcome is not guaranteed for others.
Refeeding Risks: Reintroducing food after prolonged starvation is extremely delicate due to the potentially fatal refeeding syndrome, which requires careful medical management.

In 1965, the world watched as a 27-year-old man from Scotland undertook one of the most extreme medical experiments ever recorded. Angus Barbieri, weighing 456 pounds (207 kg), began a supervised fast at Maryfield Hospital in Dundee. What was initially intended to be a short fast stretched into a monumental 382-day period with no solid food intake. His survival on a regimen of only water, tea, coffee, vitamins, and electrolytes stands as the documented record for the longest anyone has gone without food. While his story is a testament to human endurance, it is also a cautionary tale of the dangers involved in such extreme dietary measures.

The Angus Barbieri Case: A Medical Marvel

Barbieri's motivation was his extreme obesity, which had begun to seriously impact his daily life. He entered the hospital hoping for a short fast but felt so well that he insisted on continuing. Doctors at the University of Dundee monitored him closely, collecting blood and urine samples to track his health. The results consistently showed his body adapting, primarily by shifting its metabolism to burn his immense fat stores for energy through a process called ketosis.

The Fasting Regimen

During his 382-day fast, Barbieri consumed the following daily:

Water and calorie-free beverages like tea and black coffee.
Essential vitamin supplements.
Electrolytes to maintain balance within the body.
Some sources also mention small amounts of yeast extract, which could provide additional nutrients.

Remarkably, his blood glucose levels remained very low but stable for the last eight months of the fast, and he did not suffer any adverse effects. His infrequent bowel movements—as seldom as every 48 days—were also a notable part of his journey.

The Outcome and Aftermath

After a year and 17 days, Barbieri ended his fast, having lost 276 pounds (125 kg) and reaching his target weight of 180 pounds (82 kg). His first meal was a boiled egg with bread and butter, which he reported enjoying immensely. Five years later, a follow-up study found he had maintained a healthy weight with no apparent long-term health issues from the fast. He later married and had two sons, passing away in 1990 at the age of 51.

The Body's Response to Prolonged Fasting

When the body is deprived of food, it enters a multi-stage metabolic process to conserve energy and fuel vital functions.

Metabolic Stages Without Food

Glucose Burning (0–24 hours): In the initial phase, the body uses its readily available glucose from food and converts liver and muscle glycogen stores into glucose for energy.
Gluconeogenesis (18–48 hours): Once glycogen is depleted, the body begins creating glucose from other sources, primarily from the breakdown of protein in muscle tissue. This is a temporary measure to supply the brain with energy.
Ketosis (48–72+ hours): For prolonged fasting, the body dramatically increases its fat breakdown, converting fatty acids into ketone bodies in the liver. Ketones become the primary fuel for the brain and other organs, a key adaptation to spare muscle tissue.

Ethical and Medical Considerations

It is crucial to understand that Angus Barbieri's case was an anomaly conducted under strict, continuous medical supervision, and similar prolonged fasts are extremely dangerous.

Comparison of Normal Fasting vs. Extreme Fasting


Aspect	Medically Supervised Extreme Fast (Barbieri)	Unsupervised Extreme Fasting or Starvation
Duration	Record-setting 382 days (over a year).	Unpredictable, often leads to death within 1-2 months.
Liquid Intake	Regular intake of water, tea, coffee, and mineral water.	Often severely restricted, leading to rapid dehydration.
Nutritional Support	Received vitamin and electrolyte supplements.	No supplements, leading to severe deficiencies.
Medical Oversight	Continuous monitoring by doctors and university researchers.	None, leading to missed life-threatening complications.
Energy Source	Sustained by large fat reserves, adapted to ketosis.	Eventually depletes fat, breaking down critical muscle tissue and organs.
Outcome	Successful weight loss, maintained for years.	Often fatal, with heart failure being a significant risk.

Conclusion

Angus Barbieri's extraordinary 382-day fast serves as a unique data point in medical history, showcasing the human body's remarkable capacity for adaptation under extreme duress. However, his case is a profound exception, possible only due to his initial state of morbid obesity and the constant, vigilant oversight of a medical team. For the average individual, the safe duration without food is far shorter, and attempting such a feat without expert care is extremely hazardous. The metabolic shift to using stored fat is a protective mechanism, but it has limits, and unsupervised prolonged fasting is a life-threatening pursuit.

The Broader Context of Starvation

While Barbieri’s experience was medically monitored, other historical and research contexts, such as hunger strikes, provide further insight into human survival limits. These records show that for individuals with less body fat, the risks escalate much faster, with deaths often occurring after a month or two. The long-term consequences of starvation, even if survived, can include permanent organ damage. This is why medical authorities and organizations like Guinness World Records strongly caution against similar attempts. The body is resilient, but not invincible. When faced with starvation, it enters a state of crisis management, prioritizing essential organ function at the expense of other tissues, which is a state to be avoided at all costs.

Frequently Asked Questions

The official record holder is Angus Barbieri, a Scottish man who completed a medically supervised fast of 382 days from June 1965 to July 1966. He lost 276 pounds during this period.

Barbieri was morbidly obese, and his body was able to use his substantial fat reserves as its primary fuel source after depleting his glucose stores. He also received vitamin and electrolyte supplements and was under continuous medical observation.

Initially, the body uses glucose and glycogen stores. When these are depleted, it shifts to burning fat for energy through ketosis. In the absence of fat stores, it would begin breaking down vital muscle tissue and organs for energy.

No. Medically supervised cases like Barbieri’s are the exception, not the rule. Attempting an extended fast is extremely dangerous and can cause severe health complications, including heart failure and death.

No. Guinness World Records removed fasting records from its categories to discourage people from undertaking such dangerous and health-hazardous feats.

Risks include severe nutrient deficiencies, muscle loss, hormonal imbalances, impaired cognitive function, electrolyte disturbances, heart failure, and refeeding syndrome, a potentially life-threatening condition when resuming eating.

A medical study conducted years after his fast found that Barbieri had maintained a healthy weight and suffered no apparent long-term ill-effects from the extreme diet, a remarkably positive outcome.