Pope Pius XII had initially relaxed some of the regulations concerning fasting in 1956. In 1966, Pope Paul VI in his apostolic constitution Paenitemini, changed the strictly regulated Roman Catholic fasting requirements. He recommended that fasting be appropriate to the local economic situation, and that all Catholics voluntarily fast and abstain. In the United States, there are only two obligatory days of fast – Ash Wednesday and Good Friday. The Fridays of Lent are days of abstinence: eating meat is not allowed. Pastoral teachings since 1966 have urged voluntary fasting during Lent and voluntary abstinence on the other Fridays of the year. The regulations concerning such activities do not apply when the ability to work or the health of a person would be negatively affected.
But here’s something important to note about what we know from science about fasting: Though a lot of the popular interest is in weight loss, many of the key researchers who study fasting aren’t focusing on that at all. In fact, many of the studies on fasting come from institutes of aging, like this one, and the researchers behind the studies actually focus on longevity and disease prevention.

For some, fasting may be easier to maintain if viewed as a semi-regular activity throughout the week. If you don’t think you can cut down on calories every day of the week at first, try a low-calorie fast for only two days a week. However, you have to be careful about this schedule: just because you’re not fasting every day doesn’t mean that your “off days” should be used to binge on high calorie foods. 
The Church of the East strictly observes the Nineveh Fast (Som Baoutha). This annual observance occurs exactly three weeks before the start of Lent. This tradition has been practised by all Christians of Syriac traditions since the 6th century. At that time, a plague afflicted the region of Nineveh, modern-day northern Iraq. The plague devastated the city and the villages surrounding it, and out of desperation the people ran to their bishop to find a solution. The bishop sought help through the Scriptures and came upon the story of Jonah in the Old Testament. Upon reading the story, the bishop ordered a three-day fast to ask God for forgiveness. At the end of the three days, the plague had miraculously stopped, so on the fourth day the people rejoiced.
I have found that the 4:3 style fasts have worked well for my friends and me based on our work/life schedule and our personal health goals. I like that full day fasts feel like an on/off switch — I don’t think about eating on fast days and on eat days if I happen to overeat, I don’t feel guilty about it (since I’m eating at a deficit during the week). I find it more manageable to cut calories over a week (using the 4:3 style of IF) instead of every day (trying to eating less daily).
It requires less time (and potentially less money). Rather than having to prepare or purchase three to six meals a day, you only need to prepare two meals. Instead of stopping what you’re doing six times a day to eat, you simply only have to stop to eat twice. Rather than having to do the dishes six times, you only have to do them twice. Rather than having to purchase six meals a day, you only need to purchase two.
Pros: According to the founders, while everyone is technically fasting every day — during the hours when we’re not eating — most of us do so haphazardly, which makes it harder to reap the rewards. Fat Loss Forever offers a seven-day schedule for fasting so that the body can get used to this structured timetable and reap the most benefit from the fasting periods. (Plus, you get a full cheat day. And who doesn’t love that?)
3) A deeper praise. Because the body does not have to do the work of digestion, it has more energy to focus on other things. In the same vein, since we are not consumed by what we are going to eat next and when, we have more energy to devote to God. While we’re experiencing a new desire for Him through fasting, we should also emit a deeper praise as we think about everything God is to us and all He has done. Once we get caught up in our desire for God and our praise for His mighty acts, we won’t have time to be hungry or count down the hours until our fast is over. We’ll be celebrating the whole time!

On the other five days of the week, there's no calorie cap, and no food is off-limits. This freedom isn't permission to binge and make up for your two fast days, but it does mean you shouldn't feel guilty about eating a slice of cake. U.S. News experts evaluate the Fast Diet poorly in all rankings, mostly due to its tough-to-follow nature and health risks in some populations.

According to Scripture, personal experience and observation, fasting and prayer can also effect change on a much grander scale. I am convinced that when God's people fast with a proper biblical motive – seeking God's face not His hand – with a broken, repentant and contrite spirit, God will hear from heaven. He will heal our lives, our churches, our communities, our nation and world. Fasting and prayer can bring about a change in the direction of our nation, the nations of earth and the fulfillment of the Great Commission - this is powerful motivation in today’s unsettled world..


In the Bahá'í Faith, fasting is observed from sunrise to sunset during the Bahá'í month of 'Ala' ( 1 or 2 March – 19 or 20 March).[22] Bahá'u'lláh established the guidelines in the Kitáb-i-Aqdas. It is the complete abstaining from both food and drink during daylight hours (including abstaining from smoking). Consumption of prescribed medications is not restricted. Observing the fast is an individual obligation and is binding on Bahá'ís between 15 years (considered the age of maturity) and 70 years old.[22] Exceptions to fasting include individuals younger than 15 or older than 70; those suffering illness; women who are pregnant, nursing, or menstruating; travellers who meet specific criteria; individuals whose profession involves heavy labor and those who are very sick, where fasting would be considered dangerous. For those involved in heavy labor, they are advised to eat in private and generally to have simpler or smaller meals than are normal.
×