Nutrition Diet: What's the longest someone has gone without food?

October 31, 2025 •

4 min read

In 1965, a Scottish man named Angus Barbieri set a record for what's the longest someone has gone without food? by completing a medically supervised fast of 382 days. This astonishing feat highlights the body's extreme metabolic adaptations but also serves as a profound cautionary tale about the immense dangers of unsupervised, prolonged starvation.

Quick Summary

This article examines the extraordinary case of Angus Barbieri, who fasted for over a year under strict medical supervision. It details the metabolic processes his body underwent, the significant health risks associated with such extreme dieting, and contrasts his case with modern, safe approaches to nutrition and healthy eating.

Key Points

Longest Fast Record: The longest documented fast without solid food was 382 days, completed by Angus Barbieri in 1966 under strict medical supervision.
The Science of Survival: The human body can survive prolonged fasting by transitioning from burning carbohydrates (glycogen) to utilizing stored fat for energy in a process called ketosis.
Risk of Refeeding Syndrome: A major danger of prolonged fasting is refeeding syndrome, a potentially fatal complication from reintroducing food too quickly.
Importance of Medical Oversight: Barbieri's fast was only possible because of constant medical supervision to manage electrolyte levels and monitor organ function.
Balanced Nutrition is Key: A healthy nutrition diet focused on balanced meals and sustainable habits is the safest and most effective approach for long-term health and weight management, unlike extreme starvation.

The Record-Holding Fast of Angus Barbieri

In 1965, 27-year-old Angus Barbieri, a morbidly obese man from Scotland, decided to address his weight problem by embarking on a fast. Weighing 456 pounds (207 kg), he entered Maryfield Hospital in Dundee for what was initially planned as a short fast. However, as the fast progressed, he reportedly felt so well that he insisted on continuing under the strict supervision of doctors. He lived on a calorie-free regimen of tea, coffee, sparkling water, vitamins, electrolytes, and yeast extract.

For an astonishing 382 days—one year and 17 days—Barbieri consumed no solid food. During this time, his doctors regularly monitored his blood sugar and overall health, noting surprisingly stable levels despite the extreme starvation. By the end of his fast in 1966, he had lost 276 pounds (125 kg), reaching his goal weight of 180 pounds (82 kg). The case, documented in the Postgraduate Medical Journal, concluded that the prolonged fasting had no ill-effects on him. Barbieri maintained a healthy weight for the rest of his life, which lasted until 1990.

The Metabolic Shift During Prolonged Starvation

Barbieri's survival was made possible by his body's ability to undergo significant metabolic changes to adapt to prolonged starvation. This process, which happens to some extent in any fast, was taken to the extreme in his case due to his large fat reserves.

The Body's Survival Fuel:

Initial Phase (Glycogen Depletion): In the first 24 to 48 hours without food, the body uses its stored carbohydrates, or glycogen, primarily from the liver, as its main source of energy.
Mid-Phase (Fat Oxidation): Once glycogen stores are depleted, the body shifts to burning its fat reserves for fuel. This process, called ketosis, produces ketone bodies, which can be used by most tissues, including the brain. Barbieri's massive weight meant he had a vast amount of fat to burn, allowing him to endure the fast for a very long period.
Protein Sparing: During this adaptation, the body prioritizes sparing muscle protein and other vital tissues, using them only when fat reserves are significantly depleted. This mechanism is crucial for survival, as muscle loss is one of the most dangerous consequences of starvation.

The Extreme Risks of Unsupervised Fasting

Despite Angus Barbieri's success, his case is a rare exception under strict medical conditions and is not a blueprint for safe weight loss. Modern health experts strongly warn against prolonged, unsupervised fasting due to a high risk of serious complications.

Potential Dangers:

Refeeding Syndrome: This is a potentially fatal condition that can occur when food is reintroduced too quickly after a long period of starvation. It causes severe shifts in fluid and electrolyte levels, which can lead to heart failure and other complications. Barbieri's refeeding process was carefully managed by his doctors to avoid this.
Electrolyte Imbalances: As seen in Barbieri's case, monitoring electrolytes like potassium and magnesium is critical. Severe imbalances can cause irregular heart rhythms and cardiac arrest.
Nutrient Deficiencies: Prolonged fasting can lead to deficiencies in essential vitamins and minerals, which can harm organ function and weaken the immune system. Barbieri received supplemental vitamins and minerals to mitigate this risk.
Muscle Mass Loss: Although the body tries to spare protein, some muscle loss is inevitable during extended periods without solid food, especially after fat reserves are used up.
Cardiovascular Strain: Extreme dieting and weight loss can place a significant strain on the heart, particularly in individuals with pre-existing conditions.

Comparison: Extreme Fasting vs. Healthy Nutrition

While Barbieri's fast is a historical footnote, modern nutrition science focuses on sustainable, balanced, and safe practices. The table below highlights the critical differences.


Feature	Angus Barbieri's Fast	Modern, Healthy Nutrition Diet
Goal	Extreme weight loss under emergency conditions	Sustainable weight management, overall health, and wellness
Duration	382 days (extremely prolonged)	Intermittent periods (e.g., 16:8) or daily energy balance
Consumption	Water, coffee, tea, vitamins, electrolytes	Balanced meals with all macronutrients and micronutrients
Medical Supervision	Required and strictly enforced by doctors	Self-directed but often aided by dietitians or doctors
Risks	High risk of refeeding syndrome, electrolyte imbalances, heart issues	Minimal risks when done correctly; potential for deficiencies if poorly managed
Sustained Results	Achieved; maintained a healthy weight post-fast	Focuses on lifestyle changes for long-term health and weight maintenance

The Role of a Balanced Nutrition Diet Today

Instead of extreme starvation, modern nutrition diet plans emphasize consuming a balanced and nutrient-dense diet. A healthy diet supports all bodily functions, prevents deficiencies, and promotes overall well-being in a safe, controlled manner.

Key components of a healthy nutrition diet include:

Complex Carbohydrates: Provides a steady source of energy, prevents crashes, and supports brain function.
Lean Proteins: Essential for building and repairing tissues, including muscle mass.
Healthy Fats: Supports cellular function and hormone production.
Vitamins and Minerals: Sourced from a wide variety of fruits and vegetables, crucial for immune function and overall health.
Adequate Hydration: Ensures proper bodily function and prevents dehydration, a major risk in any form of fasting.

For those interested in forms of fasting for health benefits, such as intermittent fasting, consultation with a healthcare professional is crucial. Intermittent fasting, which involves cycling between periods of eating and fasting, is far less extreme and has shown some potential health benefits under proper guidance.

Conclusion

Angus Barbieri's 382-day fast is a legendary story of human endurance and metabolic adaptation, but it is not a recommended or safe approach to a nutrition diet. His survival was entirely dependent on strict, constant medical supervision, and his large pre-existing fat reserves. For anyone seeking to improve their health or lose weight, focusing on a balanced, nutrient-rich diet and sustainable lifestyle changes is the safest and most effective strategy. Unsupervised, prolonged fasting is a dangerous gamble with potentially life-threatening consequences.

For further reading on the science of fasting and its effects, the article "Features of a successful therapeutic fast of 382 days' duration" published in the Postgraduate Medical Journal offers a detailed medical account of the Barbieri case.

Frequently Asked Questions

During his medically supervised fast, Angus Barbieri consumed only water, tea, black coffee, sparkling water, vitamins, electrolytes, and a small amount of yeast extract, which provided some essential amino acids.

No, it was not. While he consumed water and other zero-calorie liquids, it was distinct from a water-only fast because he was given essential vitamins, electrolytes, and amino acids under constant medical care. A simple water fast for that duration would likely be fatal.

Prolonged fasting is dangerous due to severe risks like electrolyte imbalances, cardiac stress leading to heart failure, malnutrition, and the potentially fatal refeeding syndrome when eating resumes. Without medical supervision, the risk is extremely high.

According to a 1973 study published in the Postgraduate Medical Journal, a follow-up assessment found that Barbieri suffered no ill-effects from his prolonged fast. However, this positive outcome is largely attributed to the strict medical supervision and his pre-existing condition.

As his body transitioned into ketosis, burning its vast stores of fat for fuel, his appetite was reportedly suppressed. This is a known metabolic effect, and in his case, the intense hunger faded as the fast progressed.

Angus Barbieri's fast was an extreme, prolonged, medically supervised fast lasting over a year. Intermittent fasting involves cycling between eating and fasting periods, is far shorter, and focuses on timing meals rather than eliminating them entirely, making it much safer.

Absolutely not. Attempting such an extreme fast without intensive, constant medical supervision is highly dangerous and can be life-threatening. A safe and effective approach to weight loss involves a balanced diet and sustainable lifestyle changes, guided by a healthcare professional.