My stomach felt like an empty pit. There could not possibly have been anything left in the tank. I had already been on the toilet for 10 minutes, but I had not built up enough confidence to walk away. Diarrhea for reasons beyond our control is bad enough. This time it was, I admit, completely self-inflicted.

A few days earlier, I had started a bread-and-juice fast for the season of Lent. Three times a day, at normal meal times, I had a simple piece of bread (preferably multigrain, as my body begged for nutrients) and a glass of fruit juice. I was also drinking lots of water, and it was going straight through me. Fasting always sounds like a brilliant idea before the consequences hit home. Having lost some control over my bowel movements, I felt vulnerable and fragile. I was afraid. Was it really worth it? Would I make it the full 40 days, as I intended? When would my body finally adjust?

When the fast began, I was a healthy 185 pounds. Halfway through Lent, I finally felt hunger pangs. I lay in bed and cried. I was hungry, and it hurt. I had become used to feeling tired, but now I felt a shooting pain in my gut and wondered whether it would ever go away. I continued to lose a half pound each day. In the final days, I looked silly. The sleeves of my oversized golf shirt sagged below my elbows. My tattered brown belt had been adjusted not once but twice. My body weight dropped to 163 pounds. I did not want my mother to see me like this.

Fasting for a Cause

In the past decade, I have participated in several types of fasts: 40 days of bread and juice; 12 days of only liquids; and 10 days of not eating or drinking from dawn to dusk. Each time, I entered into the fast as a religious person seeking deeper communion with God and others. Each time, I fasted with a community that shared a political and moral purpose: to draw attention to the situation of men imprisoned in Guantánamo Bay, Cuba.

Stripped of most basic rights and kept hidden from public view, many of the nearly 800 people imprisoned in Guantánamo during its 17-year history resorted to hunger strikes to protest conditions of confinement as well as the indefinite nature of their detention. In 2005, a hunger strike included at least 200 of about 500 prisoners. In 2013, more than 100 of 166 prisoners joined a hunger strike. As a consequence, many were kept alive by force-feeding: A tube was shoved up their nose and down their throat, and Ensure was pumped into their stomachs twice each day. The prisoners cried out for people of faith and conscience to see their plight and recognize that they are human beings. (Forty men remain imprisoned there today, but the prison authorities no longer disclose the number of hunger strikers.)

When I experience hunger pangs or feel too exhausted to walk up a flight of stairs, I try to recall what motivated my fast in the first place.

Each of my fasts has taken place within this context. Thus, when I experience hunger pangs or feel too exhausted to walk up a flight of stairs, I try to recall what motivated my fast in the first place. I hope it helps me to share, even in a very small way, in their protest. The author of the Letter to the Hebrews writes, “Be mindful of prisoners as if sharing their imprisonment, and of the ill-treated as of yourselves, for you also are in the body” (13:3).

It is important to note that a hunger strike and a fast are related but distinct. In my view, a hunger strike is an act of protest that typically continues until demands are met or a negotiated resolution takes place. A hunger strike, often used as a last resort in a fight for justice, could result in death. A fast, on the other hand, usually has an end date. It can be motivated by a political cause, but it is often tied to personal or spiritual transformation. Fasting is a traditional discipline of the major world religions. For Christians, it is one of the pillars—along with prayer and almsgiving—of Lent.

A Larger Purpose

Even though I have always fasted for a political cause, I have learned through experience that fasting serves many other purposes, some beautiful and surprising, others more challenging. I hope my fast moves political leaders to action, but it also intimately affects those closest to me—and each person responds in a unique way. Fasting is demanding, physically and psychologically, but the graces far outweigh the challenges. Fasting changes habits, fosters connections with others and helps develop intimacy with God. I never feel closer to God than when I fast.

These are some of the profound effects I have experienced while fasting:

Fasting is a refreshing change of pace, one that helps me to become more prayerful and attentive to God in my life.

Pace of life. Fasting simplifies life and helps break me out of normal and comfortable routines. Time really slows down. Days and weeks seem to last forever. I begin to feel sluggish and exhausted. Low on energy, I act with greater intentionality. I walk at a slower pace. I do not fly up or down stairs like usual. My schedule opens up. I have all the time I want for reading, praying and writing in my journal. At the end of the day, I fall asleep earlier than usual. Fasting can be the perfect antidote for a busy life that moves too quickly. It is a refreshing change of pace, one that helps me to become more prayerful and attentive to God in my life.

Building community. I want political leaders to pay attention to my fast, but I am shy about explaining it to those closest to me. I cannot have it both ways. Whether intended or not, fasting is a public act. It radically changes our daily habits. People notice. My convictions become manifested in my body. I not only assent intellectually to certain propositions like human rights, but I embody these convictions.

Sharing food and drink with friends and family is a basic cultural practice that builds community. I cannot simply avoid community meals for 12 or more consecutive evenings. When I sit at the dinner table, however, and eat nothing or only a piece of bread, people inevitably ask why. This question puts me on the spot and makes me uncomfortable, but it also opens up important conversations that might not otherwise take place.

Whether intended or not, fasting is a public act. People notice. My convictions become manifested in my body.

When others learn about the fast, they often want to be supportive in some way. Most promise prayers, even if they disagree with the political cause. They simply admire a willingness to accept a little suffering for what one believes. When I experience a surprising surge of energy, joy and consolation during a fast, even as my body weakens, I like to attribute it to the prayers of others, which help ease the burden.

Some people even offer to join the fast, in whole or in part. They might offer to skip a particular meal or two. During the bread-and-juice fast during Lent, a colleague offered to bake bread for us. On a night she joined our larger community for dinner, she brought four different types of homemade bread with her. It was much better than the plain, store-bought bread I had been eating. The thoughtful gesture lifted our spirits and helped us to persevere in the fast.

Fasting can also create tension in community. One older priest was convinced I was wrong to fast, and he would not let go of it. Many years ago, he witnessed people who were plagued by notions of sin and guilt and who felt the need to do penance by inflicting serious pain on themselves, including by fasting. This priest feared I was doing the same. In time, however, he began to appreciate our unique reasons for fasting, and he even voiced his appreciation for our witness.

It is through the stomach that I rediscover hunger for God and for justice. It is where I get my fill.

Many hungers. Most days I attend Mass. Often it is a simple, consoling experience of prayer. Sometimes after busy workdays, it is hard to pay attention. My mind drifts, and I miss most of what is happening before me. When I fast, however, I surprisingly become more attentive at Mass. It is easier to focus on prayer, and I become more aware of my hunger on many levels. I hunger for food and for God. At Mass the physical sustenance is minimal: a tiny, tasteless wafer, and a small sip of wine. This small meal, however, a partaking in the body and blood of Jesus, always fills me. It satisfies my physical hunger, and it awakens my hunger for a deeper, more authentic spiritual life. The potent taste of the wine brings new life to my body and spirit. I find an oasis in the middle of the desert.

St. Ignatius Loyola often experienced tears as a consolation and a gift from God. Whether the tears resulted from deep joy or sorrow, he experienced it as God drawing nearer to him. I have often shared this experience but especially when fasting. My emotions are heightened during a fast. My physical hunger helps me to connect with the suffering of others, whether through involuntary malnourishment or unjust imprisonment. I cry. When I feel sad or lonely during a fast, I cannot rely on comfort food or an extra drink to numb the pain. I must face the pain and rely on what I have left at my disposal: prayer and tears. Fasting creates an opportunity to practice the heart of faith: In times of need, I am invited to turn to God alone.

•••

On Ash Wednesday in 2014, Pope Francis reflected on what Jesus said in the Sermon on the Mount about prayer, fasting and almsgiving. “Fasting makes sense if it questions our security, and if it also leads to some benefit for others, if it helps us to cultivate the style of the good Samaritan,” Pope Francis explained. “Fasting helps us to attune our hearts to the essential and to sharing. It is a sign of awareness and responsibility in the face of injustice, abuse, especially to the poor and the little ones, and it is a sign of the trust we place in God and in his providence.”

When I fast, I encounter many physical and psychological challenges. It can cause diarrhea. I lose too much weight. I feel sluggish and exhausted, making it difficult to keep pace with a busy life. In the end, though, I have learned that fasting has surprisingly little to do with physical hunger. Yet it is through the stomach that I encounter longing for integrity of body and spirit, for intimacy and connection with others. It is through the stomach that I rediscover hunger for God and for justice. It is where I get my fill.

Luke Hansen, a former associate editor of America, is a Catholic writer and speaker.