Why do we fast? From the spiritual side of not eating to the trendy diet fad

    How do you feel when you’re fasting? Does going without food make you feel more mindful — or is the whole thing just an agonizing slog as you count down the hours until you can eat again? If it’s the former, you might just be onto something. With Tisha B’Av just around the corner (the major fast in the Jewish calendar that isn’t Yom Kippur, it falls on August 10th-11th this year), fasting has become a major trend. But what are the benefits of fasting — and is its sudden surge in popularity really a good thing?

    Fasting is officially a thing, but is it healthy?

    Intermittent fasting — where you restrict eating to specific time windows — is sweeping the health and wellness world right now, and it’s not just yogis and celebrities who are taking it up. Sure, there’s late-night host Jimmy Kimmel, who made the 5:2 diet (restricting yourself to 500-600 calories two days a week) famous; and Hugh Jackman, who prefers the 16:8 (an eating window of just eight hours a day). But intermittent fasting has gone mainstream, penetrating social circles and workplaces all over the country over the past few years. There’s always someone I know doing it, and we’re all careful to avoid certain hangry colleagues twice a week.

    What’s driving it? Well, weight loss — this is about restricting calories, after all. In this respect, it works: a study in the Annual Review of Nutrition 2017 concluded that “almost any intermittent fasting regimen can result in some weight loss”.

    There’s a bunch of other health claims around intermittent fasting, too: Can it really help you live longer, or offer protection against type 2 diabetes? The jury is most definitely still out on this one. Any physical benefits are down to who’s doing the fasting, what kind of regimen they’re following, and if they’re doing it under supervision. And the science is still in its early stages; while there’s a ton of findings on calorie restriction in animals, less research has been done on human beings.

    What are the spiritual benefits of fasting?

    But there’s possibly something deeper going on here. Some of fasting’s most enthusiastic proponents love the practice for reasons that go beyond the physical, reporting that it makes them more productive, and clears out all of the brain fog (it’s all down to the boost in ketone levels, apparently). Perhaps the most famous cheerleader in this regard is Twitter CEO Jack Dorsey, who famously — and controversially — survives on just one meal a day.

    “During the day, I feel so much more focused. … You have this very focused point of mind in terms of this drive,” he told CNBC.

    And while the Dorsey diet is a very extreme example and not recommended, he’s not the only well-known face taking up fasting for reasons of mindfulness. Actor Chris Pratt hit the headlines at the beginning of the year after he adopted the Daniel Fast — a 21-day plan of “prayer and fasting”, inspired by the Book of Daniel in the Old Testament. Could it be that fasting’s new adherents are trying to tap into something that has been a part of religious life across pretty much all faiths since ancient times?

    While Jewish fasting centers around the rather solemn pillars of penitence and mourning (upcoming Tisha B’Av marks the destruction of the First and Second Temples), it’s not necessarily a gloomy practice. A day free from the interruptions of mealtimes serves to concentrate the mind on higher things; the light-headedness brought on by hunger near the end of a fast day can send your thoughts traveling down some pretty interesting avenues. It’s easy to slip into a more meditative state when you’re fasting, and where the Silicon Valley-types like to channel this into boosting productivity, in a Jewish context, it might just provide a link to something more esoteric.

    Of course, a Jewish fast day is not quite the same as your modern-day biohacking. It helps that these fast days are communal affairs, and that, unlike intermittent fasting programs, they’re restricted to certain days of the year, prompting a sense of community and occasion. In Judaism, there’s also a very clear link between body and soul, so it’s not too fanciful to think that the physical deprivation of fasting might invite a spiritual payoff.

    What, then, are the benefits? Oakland’s Rabbi Mark Bloom can list a fair few. “Firstly, [fasting] forces us to think unselfishly, about something bigger than ourselves,” he explains. “Secondly, it connects us to our ancestors. Thirdly, it reminds us that we are human and not 100 percent in charge of everything that happens in the world.

    Susannah Cohen is a fashion journalist, e-commerce editor (specialist subjects: lingerie and diamonds) and Jewish mom. Recently relocated from London to the West Coast, she’s feeling a lot more spiritual these days.