A growing (and secular) fasting trend may be inspiring Christians to reclaim an ancient discipline.

By G. Jeffrey MacDonald

Just a few years ago, weight loss gurus touted the grapefruit diet as a fruitful path to slimming down. Later came the low-carbohydrate South Beach Diet, with its mantra of just say no to sugar, including from fruit. Every year or two, it seems, a new trend takes hold among the health conscious who hope it will be their ticket to shedding extra pounds.

The new big thing turns out to be an ancient spiritual practice: fasting. And it is helping fuel recovery of disciplines that have not been emphasized among Western Christians since before the mid-20th century.

Known in health circles as intermittent fasting (IF), the practice involves going without food for a regular, defined period of time. IF can take various forms, such as a daily fast for all but a few set hours each day, or a one-day fast on the same day each week.

“Intermittent fasting — it’s really a craze,” said Caroline Apovian, director of the Nutrition and Weight Management Center at Boston Medical Center.

But it is not always beneficial, Apovian said. When a person skips food for a day solely to lose weight and does so without a larger spiritual purpose, it can sometimes do more harm than good.

“The next day they’re so ravenous, and there’s such a wide variety of unhealthy food available, it could actually be detrimental,” Apovian said. There is no scientific proof that it is better for weight loss than, say, just eating smaller portions at meals, she said.

Yet fasting as part of a larger spiritual mission can have health benefits, she said, because the mission keeps a person on track rather than binging after the fast.

“If you fast one day a week for religious reasons, that may stop you the next day — even though you’re ravenous — from going to McDonald’s,” Apovian said. “Because you did it for a reason, you can use cognitive restraint the next day. … You’re thinking about why are you using restraint to fast and what does that mean for the other good things you’re going to do in your life.”

Fasting, along with prayer and almsgiving, is a hallmark practice of the 40-day Lenten season that begins Ash Wednesday (March 6, this year). The most significant Christian fast days of the year are Ash Wednesday and Good Friday (April 19). Roman Catholics are restricted to one full meal on those days and no meat on Fridays, except during feast days: Christmastide and Eastertide.

For Anglicans, codes for Lenten piety are open to broad interpretation. The Book of Common Prayer calls only for “special acts of discipline and self-denial” on weekdays of Lent, Holy Week, and most Fridays through the year. But in the spirit of voluntary sacrifice, some are embracing a greater challenge in a time when fasting is not quite so countercultural anymore.

At Notre Dame University, theologian Tim O’Malley said he sees growing numbers of his students going beyond the minimal requirement of meatless Fridays. Instead they fast from food entirely for the day, just as Roman Catholics used to do in earlier times.

“We’re trying to reclaim some of these particular traditions,” said O’Malley, academic director at the Notre Dame Center for Liturgy. “What does that mean, that I’m going to do some sort of penitential act on a Friday? The concrete acts of fasting, almsgiving, and prayer give an order or rule to life. They help structure your life.”

Broad interest in IF is fueled partly by science. Research in rodents has found those that fast periodically live longer, healthier lives than those with constant access to food. Fasting once a month among Mormons, who do it as a spiritual practice, might account for low incidence of heart disease in Utah, said epidemiologist Dr. Benjamin Horne, who conducts Intermountain Healthcare’s WONDERFUL trial to test the theory. Fasting for more than one consecutive day, including four times per year during the liturgical calendar’s Ember Days, kickstarts a fat-burning process called ketosis that helps with weight loss.

Whether IF holds more promise than other weight management techniques is yet to be seen. In the meantime, the Church is bringing structure, ritual, and spirituality to the trend simply by dusting off ancient customs that infuse it with direction and meaning.

Consider fasting before the Eucharist. It has long been customary for Christians to deny themselves food — sometimes starting before midnight or sooner — in anticipation of receiving the holy sacrament.

That practice has not always been observed vigilantly, even as the Roman Catholic requirement was lessened to no food for one hour before worship, said Erin Bishop, director of the Center for Christian Spirituality at the University of San Diego. But fasting as part of rituals could be recovered, she said, especially in a time when people are trying to start fasting and could use a framework for reflecting on what they are doing.

“It draws us into solidarity with people who don’t have food readily available,” Bishop said. “It broadens our perspective of what our prayers are and what the purpose of our faith is: to understand ourselves as people of God, united as brothers and sisters.”

Health concerns might start people on the road to fasting, but pastoral leaders hope they will discover more by making it into a spiritual discipline. One might, for instance, begin Fridays by receiving Holy Communion and keep the fast for the rest of the day, suggests the Rev. Matthew Olver, assistant professor of liturgics and pastoral theology at Nashotah House Theological Seminary.

“Simply fasting, without giving any space to pray or listen to God, certainly isn’t allowing fasting as a discipline to do all it can do,” Olver said.