[Altair]

Interesting article:

Clinical, Psychological, and Personality Correlates of Asceticism in Anorexia Nervosa: From Saint Anorexia to Pathologic Perfectionism
https://www.researchgate.net/publica..._Perfectionism


Interesting book that deals with such topics as starvation, sleep deprivation, and self-injurious behaviour: The Mystic Mind
https://www.ipsepa.com/content/uploa...d-ascetics.pdf

While most of the heroic ascetics did not engage in heavy manual labor or child-bearing which would increase their caloric and mineral requirements, their severe dietary restrictions, using the ordinary marginal medieval diet as a taking-off point, were such as to bring them into starvation conditions. For example, Guthlac (674–714), after he became a solitary hermit in the fens of what is now East Anglia, was said to observe the following dietary regimen:

So great indeed was the abstinence of his daily life that from the time when he began to inhabit the desert he ate no food of any kind except that after sunset he took a scrap of barley bread and a small cup of muddy water. For when the sun reached its western limits, then he thankfully tasted some little provision for the needs of this mortal life.

If we calculate Guthlac’s daily diet as one cup of barley bread, this would give him about 700 calories, 19 grams protein, no vitamin A or C, and insufficient B vitamins. It is possible that the cup of muddy water did contain some nutrients and minerals. The effects of such austere diets are additive, even allowing for the possibility of some degree of exaggeration in his asceticism. The text proceeds to describe how Guthlac was able to resist the temptation, hinted at in many saints’ lives, to extend the fast ever more severely. Two devils in human form appear to Guthlac, compliment him on the power of his faith, and offer to instruct him in the lives of the ancient hermits.

For Moses and Elijah and the Savior of the human race Himself first of all scaled the heights of fasting: moreover those famous monks who inhabited Egypt destroyed the vices of human weakness with the sword of abstinence. And therefore if you wish to wash away your sins committed in the past and to destroy those that threaten, afflict your flesh with the whips of abstinence and crush the arrogance of your mind with the rods of fasting. For in so far as you are broken down in this world, you shall be made whole and firm in eternity.