Observations recorded throughout modern history reflect the benefit of low-carbohydrate nutrition. Herodotus tells of the meeting between a Persian delegation and the king of Ethiopia in the fifth century B.C., and of the curiosity of the Ethiopian king concerning Cambyses, the Persian king:
Finally (the Ethiopian king) came to the wine and, having learnt the process of its manufacture, drank some and found it delicious; then, for a last question, he asked what the Persian king ate and what was the greatest age that Persians could attain. Getting in reply an account of the nature and cultivation of wheat, and hearing that the Persian king ate bread, and that people in Persia did not commonly live beyond eighty, he said he was not surprised that anyone who ate dung should die so soon, adding that the Persians would doubtlessly die younger still, if they did not keep themselves going with that drink - and here he pointed to the wine - the only thing in which he admitted the superiority of the Persians.
The Persians, in their turn, asked the Ethiopian king how long the Ethiopians lived and what they ate, and were told that most of them lived to be 120, and some even more, and that they ate boiled meat and drank milk.