EXPLAINER

Why fasting can make you feel "high"

There's a well-established link between fasting and religious ecstasy. The reason may be neurochemical

By Mary Elizabeth Williams

Published March 13, 2022 3:30PM (EDT)

Woman's hands holding an empty dish bowl (Getty Images/Marinela Malcheva)
Woman's hands holding an empty dish bowl (Getty Images/Marinela Malcheva)

It's traditional for Catholics to begin the annual Lenten season by fasting on Ash Wednesday. But this year, Pope Francis invited the world to join in participating with them on March 2. Calling for a "Day of Fasting for Peace" in solidarity with Ukraine at a general audience late last month, he announced, "I encourage believers in a special way to dedicate themselves intensely to prayer and fasting on that day. May the Queen of Peace preserve the world from the madness of war." Nine years ago, the pope led a similar call to fasting, that time for Syria.

What is it about depriving the body of sustenance that connects us so deeply with a sense of spiritual humility and enlightenment? Or to put it another way, why do we feel closer to God when we don't eat?


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Fasting has a high place of prominence in numerous major world religions, as well as even more informal practices. Muslims fast during Ramadan; Jews fast during Yom Kippur and Tisha B'Av. Buddhists fast. Hindus fast. Fasting is part of the Vision Quest in several Native American traditions. During Lent, Catholics fast in a less strenuous emulation of the biblical tale of Jesus's 40 days of prayer and fasting in the desert before his passion and death. Jesus, in his turn, was following in the footsteps of predecessors like Moses and Elijah. The primary motivation for Catholics to fast, then, — at least as it was communicated during my own religious upbringing — is to imitate the example of sacrifice. Yet for many of us who've ever attempted it, fasting can also become uniquely pleasurable.

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The ideals of fasting as an act of devotion to God, atonement for sin, and detachment from worldly temptations are recurring themes across several faiths. Whether it's following the Christian edict that "Man does not live by bread alone" or the Buddhist belief that sensual desire is one of the five hindrances to spiritual growth, consciously removing the pleasures of consumption produces, for many of us, a sense of serious, prayerful focus.

Danielle Kelvas, a physician and and contributor for Contacts Compare, says she meditates and fasts regularly — and advises her patients on intermittent fasting in their own lives. "In the Anapanasati Sutta," she says, "the Buddha talks about the five grades of rapture. When the student participates in fasting and meditation, rapture is born from tireless energy, investigation, and inquiry into the nature of hunger states. The student learns to see how hunger arises and passes away in the mind, which leads to wisdom. This mind state comes with intense pleasurable interest and luminosity."

Humans have been fasting for health reasons and a spiritual boost for thousands of years. "Hippocrates recommended fasting for patients prior to surgery and noted that fasting was effective for treating ailments such as indigestion and epilepsy," notes Ronald Smith, a registered dietician and creator of EatDrinkBinge. "It's also been used to treat gout, diabetes and heart disease."

Contemporary research seems to back up that many of the health benefits, as well as those heightened, enlightened emotional sensations fasting can evoke, are real. Thanks to the popularity of certain low-carb diets, the phenomenon known as "keto euphoria" is perhaps the most buzzed about example. Writing in Medical Hypotheses back in 2006, Andrew J. Brown of the University of New South Wales connected "the initial phase of fasting or a low-carbohydrate diet" with the mood elevation often associated with it. "These feelings have often been attributed to ketosis," he wrote, "the production of ketone bodies which can replace glucose as an energy source for the brain." Here's where it gets really intriguing. "One of these ketone bodies, β-hydroxybutyrate (BHB)," he wrote, "is an isomer of the notorious drug of abuse, GHB." A decade later, Brown was still exploring the possibilities here, citing research from the 1950's in which fasting patients described feeling a light buzz "not dissimilar to the effects of ethanol."

Limiting your food and drink intake for a set amount of time is not going to give you the equivalent experience as ingesting a party drug or a few shots of tequila. It's definitely never made me see the face of God, despite the undeniable highs I've experienced from it. But what if religious ecstasy and keto euphoria were part of the same feeling?

Deprivation does appear to have intriguing effects on the brain. A 2021 report by Dutch researchers in the journal "Nutrients" found that "In healthy humans, six months of IF [intermittent fasting] improved mood as measured with the Hospital Anxiety and Depression Scale and World Health Organization Well-being Index," and cited other a 2010 study that reported "Ramadan IF lowered the subjective feelings of depression and mania in 62 patients suffering from bipolar affective disorder." A 2015 study out of China found that "prolonged fasting and calorie restriction markedly relieved negative moods like tension, anger and confusion and enhanced the sense of euphoria among aging men." And some animal studies suggest acute fasting can increase the release of dopamine in the midbrain.

The conversation about the health rewards of fasting has become complicated and often contradictory over the last several years. Not everyone who fasts ever even gets those euphoric sensations at all, and they do not last. You can't starve your way to nirvana. Increasingly, however, research is affirming that thoughtful, regular caloric restriction can stave off some of the effects of aging, and improve cognition. My own doctor talked up intermittent fasting at my last physical, and its promising potential in heading off Alzheimer's. That's different, of course, from the periodic fasting practiced in so many different faiths. But it points to something beneficial humans seem to have instinctively gravitated towards, across multiple cultures and eras.  "It's still not clear if extended fasting has any real benefits for healthy people," says Ronald Smith, "but one thing is certain: There are powerful changes occurring in our brains when we go without food for long periods of time." And, however we choose to define them, in our souls as well.

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Mary Elizabeth Williams

Mary Elizabeth Williams is a senior writer for Salon and author of "A Series of Catastrophes & Miracles."

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