Kenneth Glad
A weight-loss attempt in 1960s Scotland turned into one of the most extreme medical cases ever documented. More than fifty years later, the prolonged fast remains unmatched and still raises questions about the limits of the human body.
Angus Barbieri began his fast on 14 June 1965 at Maryfield Hospital in Dundee, weighing roughly 207 kilograms, writes Diabetes.co.uk and the 1971 edition of Guinness World Records.
What was expected to be a short, supervised fast evolved into something far more unusual. Barbieri chose to continue, determined to reach his target weight.
Over the following months, he consumed no solid food. His intake consisted of water, tea, coffee and prescribed supplements, including vitamins and electrolytes.
His case was later recognised by Guinness as the longest recorded fast. The organisation has since distanced itself from promoting such records due to safety concerns.
How his body adapted
What stood out to doctors at the time was how Barbieri’s body adjusted. Instead of immediate collapse, his system entered ketosis, a metabolic state where stored fat becomes the primary energy source.
He did not remain hospitalised throughout. He spent much of the period at home in Tayport, returning frequently for medical monitoring such as blood and urine tests.
Over time, his hunger appeared to fade. His routine became highly controlled, centred on fluids and regular clinical supervision rather than meals.
Clinical findings showed very low blood glucose levels during the later stages. Even so, no immediate serious complications were recorded during the fast itself, according to Diabetes.co.uk.
A cautious return
By late June 1966, after 382 days, Barbieri had reduced his weight to about 82 kilograms. Reintroducing food was handled gradually to avoid shock to his system.
When he finally ate again, the moment drew media attention.
“I have forgotten what food tasted like … It went down OK. I feel a bit full but I thoroughly enjoyed it,” he told reporters at the time, according to an old issue of Chicago Tribune.
Follow-up research cited in medical literature found he maintained a stable weight years later, around 89 kilograms.
The March 1973 issue of Postgraduate Medical Journal concludes: “After 100 days of fasting there was a marked and persistent increase in the excretion of urinary cations and inorganic phosphate, which until then had been minimal. Prolonged fasting in this patient had no ill-effects.”
Today, his case is often discussed alongside modern fasting trends. While intermittent fasting is now studied for potential metabolic benefits, experts caution that extreme, prolonged fasting carries serious risks.
Diabetes.co.uk notes that extended periods without food can lead to heart complications or death, particularly without medical supervision.
Barbieri’s experience remains an outlier, not a template, but it continues to inform how researchers understand starvation, metabolism and the body’s capacity to adapt.
Sources: Diabetes.co.uk, Guinness World Records, Postgraduate Medical Journey
