I’ve long used periodic fasting as a method of cleansing and weight control. Not a fan of green juices or deprivation, my preferred method has been the french-inspired soup cleanse outlined by Mireille Guiliano in her book French Women Don’t Get Fat. It involves eating a soup comprised only of leeks, water, salt and pepper for two days then slowly re-introducing other vegetables and proteins on the third day.

I love this method for two reasons. The first being that I have a thing for brothy soups—they make me feel full with very few calories—and the second being that leeks are actually highly nourishing to the body (a quality uncommon to many more western approaches to the detox). Whenever I complete a soup cleanse, I feel empty, thin, rehydrated and replenished. Which, for the record, is way better than the opposite: feeling full, bloated, and lethargic (and I feel that way more).

I became even more aware of the effects a few months ago when I decided to deepen my fasting practice during the Catholic season of lent. On Ash Wednesday, and again on Good Friday, I abstained from all food from sunrise to sunset, forgoing lunch and eating only small meals for breakfast and dinner. Though I had slight feelings of hunger around mid-day, by the end of the day, I was surprised to discover just how good I felt.

Fasting is all the rage these days

From there I began experimenting in earnest. I wanted to see if by eating less I could actually feel better. Not just during a period of fasting, but in the long term. An article I read in Porter Magazine soon after pushed me farther in that direction. Entitled “Super Power” it featured Russian supermodel and philanthropist Natalia Vodianova who has walked the catwalk for over 15 years and counting. But it wasn’t her career that kept me captivated, it was her (very) minimal eating habits.

During a meeting with the author at the Bulgari hotel in London, Natalia “fazed the waiter by requesting porridge at lunchtime, with no milk.” Later on in the evening, Natalia doled out small dinner rations finally prompting the author to ask if there are ever any lapses in her dietary overachieving. Yes, she said. Every Saturday she shares a pastry with her daughter, eating half a pain au chocolat pastry.

I’m hoping your first thoughts here are the same as mine. H a l f a pain au chocolat? That doesn’t even seem possible (or worth it). Nonetheless, there are some basic principals that can be put into practice here. Apart from a lesson in portion control methods, a bowl of porridge with no milk or toppings weighs in at around 125 calories. And the fact that she is eating that for lunch suggests that she has replaced one of her meals for the day with a 125 calorie snack.

I really liked this idea because it didn’t feel restrictive like intermittent fasting (which involves skipping a meal altogether), and it wouldn’t disrupt my blood sugar balance (because I would still be eating something), but it would still give my body the “break” that all fasting methods feature. My stomach would have time to be hungry and somewhat empty, all so that I could digest my food properly and feel a lot better.

Can fasting help you to live longer?

There is actually a science to this. The famed Lanserhof Lans in Austria treats guests to a one to two week fast in which participants abstain from food as a method of healing their bodies. The fast is dubbed “the cure” and it is based upon F.X. Mayr Medicine, a European method of detoxing which believes “the holy grail is a healthy colon.”

“All of our health problems originate from overworked digestive organs.” an article on the method mentions, “If our intestines are stressed and require more energy and blood flow to do their jobs, it leaves less in the way of resources for other parts of the body, particularly the brain.” Certainly, it feels that way. Whenever I’m fasting I feel thinner, I can think more clearly, I have more energy, and I can even write more creatively. But is there really any proof that fasting provides health benefits? After all, a l o t of the fasting methods currently circulating the fitness circuits have more to do with hype and marketing than actual tangible facts.

Here’s what we do know: Caloric restriction has been proven to promote weight loss (in fact it’s the only thing that does), but there has been no noticeable difference between one method of reducing calories vs. another. In other words, whether you fast for 24 hours once or twice a week (like Dr. John Berardi or Brad Pilon) or you fast for 12-16 hours every single day (like Dave Asprey) the weight loss benefits are the same.

That being said, caloric restriction has been known to have many health benefits beyond weight control. Reducing caloric intake by 30% per day has been shown to extend the lifespan of yeast, worms, flies, and some mice leading many media outlets to report that caloric restriction could extend the lifespan of humans. Since then, two studies on rhesus monkeys have come close to proving that fact. “One monkey started on a 30 percent calorie restriction diet when he was 16 years old… He is now 43, a longevity record for the species… and the equivalent of a human living to 130.”

And then there’s the one and only study ever to be performed on humans: Biosphere 2 in which eight willing participants sealed themselves into the famed ecosystem and subsisted on low-calorie plant-based diets for two years. The results of the experiment had lasting effects on the “eat less to live longer” community. “Tests proved them healthier in nearly every nutritionally relevant respect than when they’d gone in, and the case for Calorie Restriction in humans was no longer purely circumstantial.”

But couldn’t fasting be dangerous to your health?

That being said, there is a dark side to overdoing it. First, there’s the fact that the most influential man in the “lower calories for longer life” community, Roy Walford, died at age 79 from ALS. As one of the eight original participants in Biosphere 2 and the author of the book The 120 Year Diet: How To Double Your Vital Years, his death prompted all kinds of commentary on the legitimacy (or lack thereof) of caloric restriction as a viable method of increasing longevity.

Here’s the fine print: It’s not all about food. Dan Buettner, a Natural Geographic explorer and researcher (and the author of several of my favorite books on the subject of diet and longevity) set out to study the world’s Blue Zones,—”five regions in Europe, Latin America, Asia and the U.S. researchers have identified as having the highest concentrations of centenarians in the world.” Among other things, he found that eating less was equated to living longer.

But he also found that there is far more to it than that. The centenarians that Dan Buettner studied did not eat less food in order to live a longer life. In other words, not a single one of them counted calories or somehow tried to live longer by altering their eating habits. Rather, they lived longer because they had a community. Because they shared every meal with good friends and drank wine together late into the evening. And yes, ate less as a result of that fact.

As Dan Buettner writes in my favorite article ever written about the eating habits of centenarians, “The Island Where People Forget To Die” (please read that article from start to finish—it’s just wonderful): “Your community makes sure you’ll always have something to eat, but peer pressure will get you to contribute something too. You’re going to grow a garden, because that’s what your parents did, and that’s what your neighbors are doing… At day’s end, you’ll share a cup of the seasonal herbal tea with your neighbor because that’s what he’s serving. Several glasses of wine may follow the tea, but you’ll drink them in the company of good friends. On Sunday, you’ll attend church, and you’ll fast before Orthodox feast days. Even if you’re antisocial, you’ll never be entirely alone. Your neighbors will cajole you out of your house for the village festival to eat your portion of goat meat.”

In other words: today’s fasting methods leave out the two reasons fasting has been a successful staple of health and longevity since the advent of civilization: community and religion. Which is why I don’t believe fasting has any real claim on health benefits without those two tenants. Fasting doesn’t exist in a vacuum. In fact, we’ve proved that fasting alone doesn’t lead to a longer lifespan. But when shared with a community and rooted in a belief system, I believe fasting can be part of a long, healthy, and well-lived life.

Why religion should still be part of fasting

Until the 20th century separated the physical act from the spiritual one, fasting was always done in conjunction with a religious ritual and in the company of community. No one abstained from eating food just for the fun of it, or in the privacy of their own homes, and they certainly didn’t do so to try to live longer. When Judeo-Christian communities fasted they did so with a specific purpose in mind: to renew their souls.

Food is sustenance. It’s nourishment. It’s what keeps us alive. To the people for whom the Old Testament was written, fasting was a way of removing physical nourishment so they would have to rely on spiritual nourishment instead. They didn’t just “stop eating” and then continue about their day. They stopped eating and started praying instead. Three times a day, at breakfast, lunch, and dinner, they devoted themselves to spiritual nourishment. They prayed, they read scripture, and they went to temple. They may not have fed their bodies, but they fed their souls instead.

Before the modern era, most communities shared a common religion. Because of this, seasons of fasting were always done in the company of good friends. When Catholic communities abstained from meat during Lent, for example, they didn’t do so in the privacy of their own homes. Instead, they got together with their friends every Friday night to share a big fish dinner. In this way, religious fasting didn’t malnourish the bodies of those participating, but rather enriched the lives of those participating. It helped them to grow closer to God and to their communities—all while eating less food.

In this way, it is reasonable to assume that religious fasting methods provide more health benefits than secular ones—if for no other reason than that they do more to enrich our overall lives. By comparison, today’s chronic methods of caloric restriction involve eating less food, but do nothing to add or enrich our lives. The net effect is a form of self-deprivation that leaves us feeling malnourished, not just in body, but also in mind and in spirit. It’s no wonder that diet alone does nothing to help with weight loss, and yet when combined with community (such as with Weight Watchers) can produce drastic results.

What is the best kind of fasting?

Before I wrote this article, I thought I would discover fasting to be the fountain of youth. Instead it led me to discover how to live more fully—without always feeling so full.

On a day to day basis, I continue to eat a smaller lunch. As it is the only meal of the day that I eat alone, I have no problem reducing it and it feels so much better on my stomach to do so. Every once in awhile when I have eaten too much, I choose a weekend to take part in Mireille Guiliano’s leek soup cleanse. Drinking only nourishing broths for two days I replace those missing calories with inspirational reading so that even when my belly is empty, my body still feels full and happy.

In the end, my fasting process has remained unchanged. It is what feels good on my body, rather than what studies have proven or disproven various calorie restriction methods. Because if all of the oldest people in the world don’t care about calories or fasting, why should I? Afterall, I don’t want to spend my life trying to be healthy. I want to be healthy because I’m living my life.