Twice a year, usually at the start of spring and fall, I drive out to Atotonilco, an ancient village about five miles from where I live, in the countryside near San Miguel de Allende in central Mexico. Outside the village, another mile or so down a winding washboard of a dirt road, hidden by dusty mesquite trees and clumps of thornbushes, I arrive in the late afternoon at a Benedictine monastery named, appropriately, La Soledad—the Solitude.

A brother in a dark-blue robe greets me at the monastery gate, and I begin a weeklong retreat of silence and fasting. I follow the nine or 10 other monks to the refectory, where we eat the evening collation: a slice of bread spread with black bean paste and a cup of hibiscus tea. I know that by the end of the week, in spite of eating only enough to stave off a grinding hunger, I will feel stronger and more energetic. I will think more clearly and have a better idea of who I am and where I want to take my life.

I am no stranger to monasteries. For eight years, right out of high school, I lived behind walls as a Catholic monk, according to the 1,500-year-old Rule of St. Benedict. It was during that time that I first learned the sacred practice of fasting. Now, almost half a century after my monastic experience, I still follow this age-old path to self-knowledge and personal spirituality.

Nourishing the Soul

Fasting means abstaining from eating certain foods—or any food—for a period of time. But it is so much more than that. “Fasting possesses great power,” writes the second-century theologian Tertullian. “If practiced with the right intention, it makes one a friend of God.”

At the heart of denying food to the body is the idea that we are instead nourishing our soul. By controlling ourselves and gaining mastery over our bodies, we open up a space within to ponder the eternal questions: who am I, where did I come from, why am I here, where am I going? We walk with God in the garden “in the cool of the day,” as Adam did.

In fact, the spiritual character of fasting has been with us since the beginning: in the book of Genesis, the Lord tells Adam and Eve, “You may eat of every tree of the garden, but of the tree of the knowledge of good and evil you shall not eat, for on that day you will surely die.” It was a great test to see whether a newly awakened humanity could live without judgment and duality, in the innocence of all-is-one.

Fasting has been a conventional discipline in religious history. Elijah fasted in the wilderness for 40 days; Moses fasted twice for 40-day periods; Jesus fasted 40 days before beginning his public life; Mohammed prayed and fasted in a cave for 40 days—later, fasting became one of the Five Pillars of Islam. Prince Siddhartha Gautama sat under the Bodhi tree and fasted for more than 40 days, during which time he “awakened” and became the Buddha. In secular history, the Greek philosopher and mathematician Pythagoras also fasted for 40 days.

Fasting for political or philosophical causes has a long tradition. Mahatma Gandhi fasted many times during his career as a proponent of nonviolent social change. His 21-day fast on behalf of India’s “untouchable” caste resulted in a historic resolution making the practice of discrimination against untouchables illegal. Countless activists over the years have gone on hunger strikes to further their aims.

Self-control and self-discipline have been the aims of fasting, whether in the context of spirituality, strength training, or character building. In epic literature, warriors like Achilles used fasting as a means of developing personal power. For medieval knights like Sir Percival, who went on a quest to find the Holy Grail, fasting was an essential part of a life of holiness and dedication.

“The philosophy of fasting calls upon us to know ourselves, to master ourselves, and to discipline ourselves—the better to free ourselves,” writes the contemporary Swiss teacher Tariq Ramadan. “To fast is to identify our dependencies and free ourselves from them.”

Fasting for the Body

For a long time, we have known that fasting is good not only for the soul but for the body too. Plato and Socrates recommended fasting for increasing mental and physical effectiveness. “Fasting is the greatest remedy—the physician within,” says Paracelsus, one of the fathers of Western medicine. Benjamin Franklin tells us, “The best of all medicines is resting and fasting.”

Recent medical studies are bearing out the wisdom of the ages. Dr. Mark Mattson, at the U.S. National Institute on Aging, has found that intermittent fasting is hugely beneficial for mind and body. “We know from animal models … we can delay the onset of Alzheimer’s and Parkinson’s,” Mattson says. It can reduce the risk of many chronic conditions such as obesity, diabetes, and cardiovascular disease.

Naturopathic doctor Mike Herbert, author of The Chemotherapy Diet, says therapeutic fasting can boost immunity by eliminating toxins stored in body fat and can reduce the craving for sugar, which feeds cancer and other degenerative diseases. “Fasting from time to time also helps us make better choices about what to eat when we are not fasting.”

In addition to the physical advantages of fasting, add the latest research indicating that it can lift depression, soothe anxiety, mitigate panic attacks, and create a state of emotional stability. University of Illinois at Chicago teams, according to the U.S. National Academy of Sciences, report that fasting decreases stress and contributes to longevity.

Heart of Monastic Tradition

The monks of old knew the secrets of living highly tuned spiritual lives aligned with age-old principles for staying healthy and well-balanced. In the monastery, I was taught the value of abstaining from or lessening my intake of food at certain times in order to bring my full attention to being nourished by the Divine Source. Today, when I take up this inspiring practice, I feel connected to the heart of monastic tradition—embracing spirit by surrendering all that I thought was essential.

Fasting 101

First time fasting? Try these tips to get started.

• Plan Ahead. Decide what you will eat and drink, and how long your fast will continue. One day without food may be just the thing for you—or a juice fast for a day or two, or a three-day abstinence from sugar. Whatever you chose, make it doable and put a sensible time limit on it. Schedule your fast for your personal downtime—not during holidays or around big social events, for instance.
• Ease Into and Out of Your Fast. The day before you begin, eat lightly—clear soups, juices, or some fruit. Break your fast with similar foods and liquids. These transitions can be counted as fast days, since you are bracketing the experience with your resolve to withdraw from food.
• Tell Only Selected People. Your family or a friend should know you are fasting, but avoid telling “the world” you are doing it, to keep it personal and private. Advertising that you are going on a fast also could set you up for failure or tempt you to outdo yourself with an endurance contest.
• Fast from the World, Spend Time Alone. News headlines can be disturbing and invasive as you go into yourself for a fast. Commercials about food can weaken your resolve. Try extending your fast from food to a withdrawal from the world’s busyness: the fewer distractions, the better.
• Rest. Fasting naturally slows us down. Take the opportunity to relax. Tell yourself there is nothing you really need to do today except to ease up and care for yourself. Take naps.
• See What Comes Up. Take time to journal about what bubbles to the surface emotionally while fasting. You are giving yourself the gift of a personal pause—use it to reflect on where you are in life, how far you have come, and what, if anything, you would like to do differently.
• Take Walks in Nature. With awareness, breathe deeply and be nourished by fresh air, the scents of water, grass, trees, and flowers. Walk barefoot. Feel yourself in nature and as a part of it.
• Know When to Fast. Pregnant women, nursing mothers, and individuals with cardiac arrhythmias or kidney or liver problems are advised not to fast.