by Rev. Fr. Dr. Chirathilattu Biji Markose
According to Bar Ebroyo, the fasting may be defined in terms of time, of the kind of food or in terms of both time and food, and they are the three different categories of fasting. He opines that the fasting, which has no regulations concerning time or the kind of food, is non-canonical and that it should be rejected.
The first kind of fasting is that of abstaining from every kind of food during the day and eating any prepared food during the night like the Muslims and the Jews.
The second kind is the fasting of the following Christians: "Greeks, Romans, Armenians, Iberians (Georgians), and Syrians from the West and from the North West."  They abstain only from the unclean food of slaughtered animals and their products such as milk and eggs, but eat simple food of grain and dry and green vegetables during the day; sometimes once at the third hour or the sixth or the ninth, at other times more than once without any regulation.
The third kind is that of the Copts, the East-Syrians and those in the Southeast.  It is the fasting of not eating anything during the whole day, from the morning until the evening, but by the evening eat simple food. Unlike those who fast till the evening and eat grilled and fried dishes, cakes and pastry, those who eat during the day eat simple food only and do not take fat and greasy food. 
Bar Ebroyo explains that the Christians have such difference in their customs of fasting, because the Apostles and the Holy Fathers simply decreed fasting in their canons without description of the manner of fasting. And he is of opinion that the first kind of the above-mentioned fasting is contrary to the meaning of fasting. Fasting aims at the weakening of the powers of the body, suppressing exciting passions, and restraining carnal desires, so that the soul obscured by material darkness may shine and its mirror may be cleansed from the stains soiling it. He who stimulates his stomach from morning until the evening and then gives it all kinds of dainty food and nice dishes, will obtain a great delight from them. This great and manifest delight results in the creeping of passions into his body. And the second kind of fasting has an intermediate position between the first and the third kind, not being as greedy as the first, neither as ascetical as the third. Therefore, Bar Ebroyo evaluates the third kind, which incidentally is the fasting practice of his own Church, as the most valuable way of fasting. 
Bar Ebroyo takes over the division by the renowned teachers on the degrees of fasting and instructs the people on it. The three degrees of fasting are the general, the particular, and the extra particular fasting. The general fast is either complete abstinence from taking food and drink during the day, as being observed by the Easterners or abstaining from eating animals and their products during the day as being done by the Westerners.  The Easterners take vegetables and herbs in the evening, and the Westerners during the day also. The particular one is preserving from the sinful inclinations not only the sense of taste but also the other senses. The extra particular one is keeping the body and its senses, and also the soul away from impure thoughts. 
He relates the four levels in the frequency of eating also.
The level of the very high is that which is not found in all the centuries. It is the level of the Perfect who received food only once in forty days, that their bodies became thin.
The level of the High is the perfection of them, who ate only on Sundays.
The middle level is that of those who eat in the evening and abstain until the next evening.
The level of the Low is the solitary's order. They eat only one time everyday.
Bar Ebroyo narrates that the 1300 Brothers in the Monastery of Pachom used to change their course. Some have eaten by the third hour, some sixth hour, some ninth hour and some others in the evening. And still some others used to eat only one time a day and others once a week. Everyone has done according to his aptitude. 
 Ethicon (ed. TEULE), p. 86. The Christians referred to here are the Eastern Orthodox Church, the Roman Catholic Church, the Armenian Orthodox Church, the Georgian Orthodox Church and the Syrian Orthodox believers under the jurisdiction of the Patriarch in the Western and North Western parts of the Church, which include Antioch, Melitene, Edessa etc.
 The name Copts stands for the Coptic Orthodox Church. Bar Ebroyo's classification, "the East-Syrians and all those in the Southeast" is a little confusing, because in accordance with Bar Ebroyo's nomenclature it can denote both the believers of the East Syrian Church or the Syrian Orthodox believers under the Maphrianate. But taking into account the fact that Bar Ebroyo mostly describes the East Syrian Church as Nestorians, we may rightly assume that here he is referring to the Syrian Orthodox believers under his jurisdiction.
 Ethicon (ed. TEULE), pp. 86-87.
 Ethicon (ed. TEULE), pp. 87-88.
 Ethicon (ed. TEULE), p. 89.
 Bar Ebroyo always describe the people who were under the jurisdiction of the Patriarch as "Westerners" and those under the jurisdiction of the Maphrian (Catholicos) as the "Easterners." Here, the detail that it is the Easterners and the Westerners who do so is not given in Ethicon.
 Liber Columbae, p. 546; Book of the Dove, pp. 27-28.
 Ethicon (ed. BEDJAN), pp. 240-241.
Source: Chirathilattu Biji Markose: "Prayers and Fasts according to Bar Ebroyo, A Study On the Prayers and Fasts of the Oriental Churches", Lit Publischers, Münster, 2004
The Material Benefits of Fasting
In accordance with the fact that Bar Ebroyo himself was a doctor, he underlines through a quotation from the doctors of his time that fasting improves the health of the body.
Fasting Enlightens the Soul
Fasting helps to have serenity of the soul because the one, who hungers in his stomach, enlightens his intellect. Therefore, the hunger is a key, which opens the door of wisdom.