While it’s true that without food we would run out of energy, how long you can go without food varies. You need look no further than a hibernating bear to see evidence.
A bear is not a human, though. Can humans last for months without food?
This question was answered in 1965 when a man went over a year without eating! 382 days to be exact. This is the longest recorded fast to date.
The patient remains unnamed, but there are a few things known about him. He was 27 years old and weighed 456 pounds at the start of his fast. Fasting was an acceptable therapy for the obese, but doing so for longer than 40 days was considered dangerous.
The patient presented himself for normal treatment, but since he adapted so well to the fasting, he decided to try and keep it up for as long as he could or until he reached his ideal weight. During this time he only had to poop every 40-50 days.
Unlike a bear in hibernation, however, the man was given vitamin supplements daily. The fast was mostly uneventful, but some adjustments had to be made to keep him healthy.
