sparrow

Posting this mostly expecting a critique of this diet, apparently there is an ultramarathoner who eats this way - I guess they get protein from seeds in the fruits, and mostly eat fruits and some veggies?
 
Again, personally I endorse this only as a temporary thing, I don't know how long it can be sustained for a lot of people. I think it overlaps with another religious fast that came up in discussion called "xerophagy", which is a raw fruits / veggies / seeds fast that I think it only supposed to be temporary for lent or maybe for committed religious people.
 
I am generally concerned with veganism as it can lead to various deficiencies. I think it can be healthy maybe spiritually, but a physically active lifestyle probably would benefit from meat consumption. I like veganism from a self-sufficienty perspective though, like it can take less resources to grow food than growing meat, but it seems like a trade off of health (which might be ok in certain circumstances if again done for spiritual reasons).
 
https://www.nomeatathlete.com/fruitarian-diet/

https://www.newadvent.org/cathen/09152a.htm
 
> For example, the historian Socrates (Church History V.22) tells of the practice of the fifth century: "Some abstain from every sort of creature that has life, while others of all the living creatures eat of fish only. Others eat birds as well as fish, because, according to the Mosaic account of the Creation, they too sprang from the water; others abstain from fruit covered by a hard shell and from eggs. Some eat dry bread only, others not even that; others again when they have fasted to the ninth hour (three o'clock) partake of various kinds of food". Amid this diversity some inclined to the extreme limits of rigor. Epiphanius, Palladius, and the author of the "Life of St. Melania the Younger" seem to contemplate a state of things in which ordinary Christians were expected to pass twenty-four hours or more without food of any kind, especially during Holy Week, while the more austere actually subsisted during part or the whole of Lent upon one or two meals a week (see Rampolla, "Vita di. S. Melania Giuniore", appendix xxv, p. 478). But the ordinary rule on fasting days was to take but one meal a day and that only in the evening, while meat and, in the early centuries, wine were entirely forbidden. During Holy Week, or at least on Good Friday it was common to enjoin the xerophagiæ, i.e., a diet of dry food, bread, salt, and vegetables.
 
> There does not seem at the beginning to have been any prohibition of lacticinia, as the passage just quoted from Socrates would show. Moreover, at a somewhat later date, Bede tells us of Bishop Cedda, that during Lent he took only one meal a day consisting of "a little bread, a hen's egg, and a little milk mixed with water" (Church History III.23), while Theodulphus of Orleans in the eighth century regarded abstinence from eggs, cheese, and fish as a mark of exceptional virtue. None the less St. Gregory writing to St. Augustine of England laid down the rule, "We abstain from flesh meat, and from all things that come from flesh, as milk, cheese, and eggs." This decision was afterwards enshrined in the "Corpus Juris", and must be regarded as the common law of the Church. Still exceptions were admitted, and dispensations to eat "lacticinia" were often granted upon condition of making a contribution to some pious work. These dispensations were known in Germany as Butterbriefe, and several churches are said to have been partly built by the proceeds of such exceptions. One of the steeples of Rouen cathedral was for this reason formerly known as the Butter Tower. This general prohibition of eggs and milk during Lent is perpetuated in the popular custom of blessing or making gifts of eggs at Easter, and in the English usage of eating pancakes on Shrove Tuesday.

https://www.newadvent.org/cathen/09152a.htm
 
> For example, the historian Socrates (Church History V.22) tells of the practice of the fifth century: "Some abstain from every sort of creature that has life, while others of all the living creatures eat of fish only. Others eat birds as well as fish, because, according to the Mosaic account of the Creation, they too sprang from the water; others abstain from fruit covered by a hard shell and from eggs. Some eat dry bread only, others not even that; others again when they have fasted to the ninth hour (three o'clock) partake of various kinds of food". Amid this diversity some inclined to the extreme limits of rigor. Epiphanius, Palladius, and the author of the "Life of St. Melania the Younger" seem to contemplate a state of things in which ordinary Christians were expected to pass twenty-four hours or more without food of any kind, especially during Holy Week, while the more austere actually subsisted during part or the whole of Lent upon one or two meals a week (see Rampolla, "Vita di. S. Melania Giuniore", appendix xxv, p. 478). But the ordinary rule on fasting days was to take but one meal a day and that only in the evening, while meat and, in the early centuries, wine were entirely forbidden. During Holy Week, or at least on Good Friday it was common to enjoin the xerophagiæ, i.e., a diet of dry food, bread, salt, and vegetables.
 
> There does not seem at the beginning to have been any prohibition of lacticinia, as the passage just quoted from Socrates would show. Moreover, at a somewhat later date, Bede tells us of Bishop Cedda, that during Lent he took only one meal a day consisting of "a little bread, a hen's egg, and a little milk mixed with water" (Church History III.23), while Theodulphus of Orleans in the eighth century regarded abstinence from eggs, cheese, and fish as a mark of exceptional virtue. None the less St. Gregory writing to St. Augustine of England laid down the rule, "We abstain from flesh meat, and from all things that come from flesh, as milk, cheese, and eggs." This decision was afterwards enshrined in the "Corpus Juris", and must be regarded as the common law of the Church. Still exceptions were admitted, and dispensations to eat "lacticinia" were often granted upon condition of making a contribution to some pious work. These dispensations were known in Germany as Butterbriefe, and several churches are said to have been partly built by the proceeds of such exceptions. One of the steeples of Rouen cathedral was for this reason formerly known as the Butter Tower. This general prohibition of eggs and milk during Lent is perpetuated in the popular custom of blessing or making gifts of eggs at Easter, and in the English usage of eating pancakes on Shrove Tuesday.

https://www.newadvent.org/cathen/09152a.htm
 
> For example, the historian Socrates (Church History V.22) tells of the practice of the fifth century: "Some abstain from every sort of creature that has life, while others of all the living creatures eat of fish only. Others eat birds as well as fish, because, according to the Mosaic account of the Creation, they too sprang from the water; others abstain from fruit covered by a hard shell and from eggs. Some eat dry bread only, others not even that; others again when they have fasted to the ninth hour (three o'clock) partake of various kinds of food". Amid this diversity some inclined to the extreme limits of rigor. Epiphanius, Palladius, and the author of the "Life of St. Melania the Younger" seem to contemplate a state of things in which ordinary Christians were expected to pass twenty-four hours or more without food of any kind, especially during Holy Week, while the more austere actually subsisted during part or the whole of Lent upon one or two meals a week (see Rampolla, "Vita di. S. Melania Giuniore", appendix xxv, p. 478). But the ordinary rule on fasting days was to take but one meal a day and that only in the evening, while meat and, in the early centuries, wine were entirely forbidden. During Holy Week, or at least on Good Friday it was common to enjoin the xerophagiæ, i.e., a diet of dry food, bread, salt, and vegetables.
 
> There does not seem at the beginning to have been any prohibition of lacticinia, as the passage just quoted from Socrates would show. Moreover, at a somewhat later date, Bede tells us of Bishop Cedda, that during Lent he took only one meal a day consisting of "a little bread, a hen's egg, and a little milk mixed with water" (Church History III.23), while Theodulphus of Orleans in the eighth century regarded abstinence from eggs, cheese, and fish as a mark of exceptional virtue. None the less St. Gregory writing to St. Augustine of England laid down the rule, "We abstain from flesh meat, and from all things that come from flesh, as milk, cheese, and eggs." This decision was afterwards enshrined in the "Corpus Juris", and must be regarded as the common law of the Church. Still exceptions were admitted, and dispensations to eat "lacticinia" were often granted upon condition of making a contribution to some pious work. These dispensations were known in Germany as Butterbriefe, and several churches are said to have been partly built by the proceeds of such exceptions. One of the steeples of Rouen cathedral was for this reason formerly known as the Butter Tower. This general prohibition of eggs and milk during Lent is perpetuated in the popular custom of blessing or making gifts of eggs at Easter, and in the English usage of eating pancakes on Shrove Tuesday.

tl;dr it's uncomfortable clothing or like how it feels after you get a haircut and there's hair on you and it's itchy and scratchy, as a form of discipline and penance
  
via Catholic Encyclopedia:
  
https://www.newadvent.org/cathen/07113b.htm
  
(Latin cilicium; French cilice).
  
> A garment of rough cloth made from goats' hair and worn in the form of a shirt or as a girdle around the loins, by way of mortification and penance. The Latin name is said to be derived from Cilicia, where this cloth was made, but the thing itself was probably known and used long before this name was given to it. The sackcloth, for instance, so often mentioned in Holy Scripture as a symbol of mourning and penance, was probably the same thing; and the garment of camels' hair worn by St. John the Baptist was no doubt somewhat similar. The earliest Scriptural use of the word in its Latin form occurs in the Vulgate version of Psalm 34:13, "Ego autem, cum mihi molesti essent, induebar cilicio." This is translated hair-cloth in the Douay Bible, and sackcloth in the Anglican Authorized Version and the Book of Common Prayer.
  
> During the early ages of Christianity the use of hair-cloth, as a means of bodily mortification and as an aid to the wearer in resisting temptations of the flesh, became very common, not only amongst the ascetics and those who aspired to the life of perfection, but even amongst ordinary lay people in the world, who made it serve as an unostentatious antidote for the outward luxury and comfort of their lives. St. Jerome, for instance, mentions the hairshirt as being frequently worn under the rich and splendid robes of men in high worldly positions. St. Athanasius, St. John Damascene, Theodoret, and many others also bear testimony to its use in their times. Cassian, however, disapproved of it being used by monks, as if worn outside it was too conspicuous and savoured of vanity and if underneath it hindered the freedom of the body in performing manual labour. St. Benedict does not mention it specifically in his rule, but van Haeften maintains that it was worn by many of the early Benedictines, though not prescribed universally throughout the order.
  
> Later on, it was adopted by most of the religious orders of the Middle Ages, in imitation of the early ascetics, and in order to increase the discomfort caused by its use it was sometimes even made of fine wire. It was not confined to the monks, but continued to be fairly common amongst lay people also. Charlemagne, for instance, was buried in the hairshirt he had worn during life (Martene, "De Ant. Eccl. Rit."). The same is recorded of St. Thomas of Canterbury. There was also a symbolic use made of hair-cloth. St. Augustine says that in his time candidates for baptism stood with bare feet on hair-cloth during a portion the ceremony (De Symb. ad Catech., ii, 1). Penitents wore it on Ash Wednesday, and in the Sarum Rite a hair-cloth banner was carried in procession at their reconciliation on Maundy Thursday. The altar, too, was sometimes covered with the same material at penitential seasons.
  
> In modern times the use of the hairshirt has been generally confined to the members of certain religious orders. At the present day only the Carthusians and Carmelites wear it by rule; with others it is merely a matter of custom or voluntary mortification. Objections have been raised against its use on sanitary grounds, but it must be remembered that ideas as to personal cleanliness have changed with the advance of civilization, and that what was considered a sign of, or aid to, piety in past ages need not necessarily be regarded in the same light now, and vice versa, but the ideas and practices of the ancients must not for that reason be condemned by us, because we happen to think differently.

tl;dr it's uncomfortable clothing or like how it feels after you get a haircut and there's hair on you and it's itchy and scratchy, as a form of discipline and penance
  
via Catholic Encyclopedia:
  
https://www.newadvent.org/cathen/07113b.htm
  
(Latin cilicium; French cilice).
  
> A garment of rough cloth made from goats' hair and worn in the form of a shirt or as a girdle around the loins, by way of mortification and penance. The Latin name is said to be derived from Cilicia, where this cloth was made, but the thing itself was probably known and used long before this name was given to it. The sackcloth, for instance, so often mentioned in Holy Scripture as a symbol of mourning and penance, was probably the same thing; and the garment of camels' hair worn by St. John the Baptist was no doubt somewhat similar. The earliest Scriptural use of the word in its Latin form occurs in the Vulgate version of Psalm 34:13, "Ego autem, cum mihi molesti essent, induebar cilicio." This is translated hair-cloth in the Douay Bible, and sackcloth in the Anglican Authorized Version and the Book of Common Prayer.
  
> During the early ages of Christianity the use of hair-cloth, as a means of bodily mortification and as an aid to the wearer in resisting temptations of the flesh, became very common, not only amongst the ascetics and those who aspired to the life of perfection, but even amongst ordinary lay people in the world, who made it serve as an unostentatious antidote for the outward luxury and comfort of their lives. St. Jerome, for instance, mentions the hairshirt as being frequently worn under the rich and splendid robes of men in high worldly positions. St. Athanasius, St. John Damascene, Theodoret, and many others also bear testimony to its use in their times. Cassian, however, disapproved of it being used by monks, as if worn outside it was too conspicuous and savoured of vanity and if underneath it hindered the freedom of the body in performing manual labour. St. Benedict does not mention it specifically in his rule, but van Haeften maintains that it was worn by many of the early Benedictines, though not prescribed universally throughout the order.
  
> Later on, it was adopted by most of the religious orders of the Middle Ages, in imitation of the early ascetics, and in order to increase the discomfort caused by its use it was sometimes even made of fine wire. It was not confined to the monks, but continued to be fairly common amongst lay people also. Charlemagne, for instance, was buried in the hairshirt he had worn during life (Martene, "De Ant. Eccl. Rit."). The same is recorded of St. Thomas of Canterbury. There was also a symbolic use made of hair-cloth. St. Augustine says that in his time candidates for baptism stood with bare feet on hair-cloth during a portion the ceremony (De Symb. ad Catech., ii, 1). Penitents wore it on Ash Wednesday, and in the Sarum Rite a hair-cloth banner was carried in procession at their reconciliation on Maundy Thursday. The altar, too, was sometimes covered with the same material at penitential seasons.
  
> In modern times the use of the hairshirt has been generally confined to the members of certain religious orders. At the present day only the Carthusians and Carmelites wear it by rule; with others it is merely a matter of custom or voluntary mortification. Objections have been raised against its use on sanitary grounds, but it must be remembered that ideas as to personal cleanliness have changed with the advance of civilization, and that what was considered a sign of, or aid to, piety in past ages need not necessarily be regarded in the same light now, and vice versa, but the ideas and practices of the ancients must not for that reason be condemned by us, because we happen to think differently.

tl;dr it's uncomfortable clothing or like how it feels after you get a haircut and there's hair on you and it's itchy and scratchy, as a form of discipline and penance
  
via Catholic Encyclopedia:
  
https://www.newadvent.org/cathen/07113b.htm
  
(Latin cilicium; French cilice).
  
> A garment of rough cloth made from goats' hair and worn in the form of a shirt or as a girdle around the loins, by way of mortification and penance. The Latin name is said to be derived from Cilicia, where this cloth was made, but the thing itself was probably known and used long before this name was given to it. The sackcloth, for instance, so often mentioned in Holy Scripture as a symbol of mourning and penance, was probably the same thing; and the garment of camels' hair worn by St. John the Baptist was no doubt somewhat similar. The earliest Scriptural use of the word in its Latin form occurs in the Vulgate version of Psalm 34:13, "Ego autem, cum mihi molesti essent, induebar cilicio." This is translated hair-cloth in the Douay Bible, and sackcloth in the Anglican Authorized Version and the Book of Common Prayer.
  
> During the early ages of Christianity the use of hair-cloth, as a means of bodily mortification and as an aid to the wearer in resisting temptations of the flesh, became very common, not only amongst the ascetics and those who aspired to the life of perfection, but even amongst ordinary lay people in the world, who made it serve as an unostentatious antidote for the outward luxury and comfort of their lives. St. Jerome, for instance, mentions the hairshirt as being frequently worn under the rich and splendid robes of men in high worldly positions. St. Athanasius, St. John Damascene, Theodoret, and many others also bear testimony to its use in their times. Cassian, however, disapproved of it being used by monks, as if worn outside it was too conspicuous and savoured of vanity and if underneath it hindered the freedom of the body in performing manual labour. St. Benedict does not mention it specifically in his rule, but van Haeften maintains that it was worn by many of the early Benedictines, though not prescribed universally throughout the order.
  
> Later on, it was adopted by most of the religious orders of the Middle Ages, in imitation of the early ascetics, and in order to increase the discomfort caused by its use it was sometimes even made of fine wire. It was not confined to the monks, but continued to be fairly common amongst lay people also. Charlemagne, for instance, was buried in the hairshirt he had worn during life (Martene, "De Ant. Eccl. Rit."). The same is recorded of St. Thomas of Canterbury. There was also a symbolic use made of hair-cloth. St. Augustine says that in his time candidates for baptism stood with bare feet on hair-cloth during a portion the ceremony (De Symb. ad Catech., ii, 1). Penitents wore it on Ash Wednesday, and in the Sarum Rite a hair-cloth banner was carried in procession at their reconciliation on Maundy Thursday. The altar, too, was sometimes covered with the same material at penitential seasons.
  
> In modern times the use of the hairshirt has been generally confined to the members of certain religious orders. At the present day only the Carthusians and Carmelites wear it by rule; with others it is merely a matter of custom or voluntary mortification. Objections have been raised against its use on sanitary grounds, but it must be remembered that ideas as to personal cleanliness have changed with the advance of civilization, and that what was considered a sign of, or aid to, piety in past ages need not necessarily be regarded in the same light now, and vice versa, but the ideas and practices of the ancients must not for that reason be condemned by us, because we happen to think differently.