I have personally observed for two or three years men, who were foregoing starches, and in general their bodies were slight and their complexions good. They could withstand wind, cold, heat, or dampness, but there was not a fat one among them. I admit that I have not yet met any who had not eaten starches in several decades, but if some people cut off from starches for only a couple of weeks die while these others look as well as they do after years, why should we doubt that the (deliberate) fasting could be prolonged still further? If those cut off from starches grow progressively weaker to death, one would normally fear that such a diet simply cannot be prolonged, but inquiry of those pursuing this practice reveals that at first all of them notice a lessening of strength, but that later they gradually get stronger month by month and year by year. Thus, there is no impediment to the possibility of prolongation.

Therefore, by giving up starches one can become immune to weapons, exorcize demons, neutralize poisons, and cure illnesses. On entering a mountain, he can render savage beasts harmless. When he crosses streams, no harm will be done to him by dragons. There will be no fear when plague strikes; and when a crisis or difficulty suddenly arises, you will know how to cope with it.

Source: https://www.reddit.com/r/carnivore/comments/v4amne/just_something_interesting_about_historical_diets/ - u/genesisages

“The Daoist Immortals are often described as “abstaining from grain” (bigu) as part of their training and progression in the Dao… Likewise, the “abstention from grain” of Saints must be seen to be a fundamental technique of achieving immortality, perhaps only inferior to a magical plant or elixir that would instantly fulfill the same function as the practice of bigu.” (Dannaway, Frederick R. (2009)Yoked to Earth: A Treatise on Corpse-Demons and Bigu)

The “cutting off” of grains, which were the basic staple food for the peasants, was a rejection of the sedentary life and the peasant condition as such. This refusal should not solely be interpreted in the light of the miseries endured by farmers, but also in a much more fundamental way. Agriculture has occasioned, since Neolithic times, a radical break with the way of life that prevailed for almost the entire prehistory of humankind. Agriculture has also been the main culprit of the imbalances of human civilization over the last ten thousand years or so: the systematic destruction of the natural environment, overpopulation, capitalization, and other evils that result from sedentariness. (Schipper, Kristofer (1993), The Taoist Body, translated by Karen C. Duval, University of California Press. p. 170)

“What becomes evident in the study of the tensions between Confucians and Daoists is a fundamental difference in their assessments of the prehistorical period of China. The Confucian’s viewed primordial times as period of starvation, of violence and wilderness, to loosely paraphrase and translate Levi (1982), contrasted to the Daoist view of a golden-age of uncontrived Eden-like bliss. “Zhuangzi praises that idyllic age with these words: ‘Spirits and gods show their good will and nobody dies before his time’” (Levi 1982). This is anathema to the Confucian view that it took a civilizing divine-potentate to rescue humanity from it’s own ignorance and helplessness in a brutal wilderness. This expresses a fundamental cosmological orientation that is the foundation for much of the social movements in China, perhaps even into modern times.“ Ancient man imbibed dew” and “fed on primordial breath and drink harmony” and ate not the toilsome, vulgar crops of the red dust that are exemplified in the Five Sacred Grains (wuku).”  (Dannaway, Frederick R. (2009)Yoked to Earth: A Treatise on Corpse-Demons and Bigu)