The body does not run on meals.
It runs on a store, and meals top the store up. Skip enough of them and the store is simply what remains.
Which turns the question from how long a person can go without food into something narrower and much stranger.
How large is the store, what runs out first, and is it the fuel at all.
The answer for most people is that fuel is not the limit and never was.
Something else gives way long before it.
The fuel switch happens in the first week
For the first day or two the body burns the sugar it has on hand and then starts making more from protein, which means taking it out of muscle.
That is the expensive phase, and if it continued at the starting rate a person would lose dangerous amounts of lean tissue inside a month.
It does not continue, because the liver begins converting fat into ketone bodies and the brain adapts to running on them instead.
Once that switch is complete the demand for new sugar collapses, protein breakdown drops to a fraction of its early rate, and fat becomes almost the only fuel in use.
From that point the runway is set purely by how much fat there is, and a very heavy person is carrying an enormous one.
The store lasts far longer than expected.
Tea, coffee and a multivitamin
What the store cannot supply is everything that is not energy.
Fat contains no potassium, no sodium, no vitamins and no trace minerals, so a long fast has to be topped up from outside or the chemistry goes wrong.
The intake in this case was tea, coffee, sparkling water, yeast extract and a multivitamin, with potassium and other electrolytes added when blood tests called for them.
Toward the end he sometimes took milk or sugar in the tea, which is the only calorie intake recorded anywhere in the account.
He was in hospital at the start and living at home for most of it, coming back for blood and urine samples on a schedule.
The supervision was the entire method.
Three hundred and eighty two days on the record
The fast ran from June of 1965 to June of 1966, in the care of a hospital in Dundee, with the patient aged 27 when it began.
He started at 456 pounds and finished at 180, a loss of 276 pounds over 382 days.
That works out at about three quarters of a pound a day, sustained without a break for more than a year.
The case was written up in a medical journal in 1973, and the authors reported that no ill effects had followed from the fast itself.
The same follow up found him at 196 pounds, which is 16 pounds above where he finished and a long way below where he started.
The regain almost never happens. Here it mostly did not.
Why this never became a treatment
A single case is a data point, not a protocol, and the era it belongs to explains why nobody repeated it at scale.
Total fasting was briefly fashionable as an obesity treatment in the 1960s, and it produced deaths. A report published in 1965 described lactic acidosis and a fatal outcome in a patient treated exactly that way.
The failure mode is not running out of fat. It is potassium and magnesium falling far enough to disturb the heart, or the shock of refeeding after a long gap.
Neither of those announces itself. Both are found by blood test, which is why the checks were the part that mattered and the hunger was not.
So the case stayed a case, in the way that a one of a kind machine or a laboratory concrete stays a demonstration.
Records of this type are also no longer recognized, since publishing them encourages people to try without any of the monitoring.
What the case actually proved
Strip away the record and one finding survives, and it is not about willpower.
It is that the human fat store is very large and the body is very good at switching over to it, which is a piece of physiology rather than an achievement.
Modern work on medically supervised fasting reaches the same place from the other direction, reporting mostly mild effects under observation and serious events in a tiny fraction of visits, while being explicit that the long fasts of that earlier era carried real danger.
The variable is not the person. It is whether somebody is reading the blood work.
Anyone considering prolonged fasting should be doing it with a doctor, and the record above is a reason for that rather than against it.
The supervised fast was not a feat of endurance.
It was a year of monitoring.
