Capt. Robert Falcon Scott's disastrous attempt to be the first to the South Pole resulted in his death and the death of four comrades.
British researchers say the men expended more energy than Olympic athletes as they hauled their supplies across hundreds of miles of ice and snow by hand while eating rations too high in protein and too low in fat.
As a result the five men starved to death, they said.
"There has been much speculation about what Scott died of," lead researcher Lewis Halsey of the University of Roehampton in London told the Irish Independent.
"Almost certainly his death was due to chronic and extreme emaciation."
The researchers examined the expedition's rations in light of today's knowledge of nutrition.
The rations consisted of biscuits, pemmican (a fat and protein mixture), butter, sugar, chocolate, cereals and raisins, with supplements of horse meat, an unbalanced diet inadequate to keep them alive under the extreme conditions they faced, the researchers said.