Long before juice cleanses, 5:2 diets and liver detoxes, humans have engaged in ritual deprivation.
Many Buddhist monks and nuns abstain from food from noon to dawn, Muslims observe the month of Ramadan and many Christian traditions observe a month of restraint for Lent, which this year starts today.
Many of the fasts observed by these religions don’t completely withhold any food and drink, but studies have shown observing periods of restraint around food can have health benefits, whether you do it for religious reasons or not.
What happens in your body during a fast
Eating and digesting food takes a toll on the body, and taking the odd break from that can be a good thing, says Professor Amanda Salis, who researches severe energy restriction at the University of Sydney.
“There is some collateral damage from eating, there’s also food that contain free radicals and that causes some damage to your body,” she said.
Research showed taking a break from eating can sometimes reduce risk factors for conditions such as diabetes and heart disease, she said.
“We don’t know yet if this means a reduction in the incidence of those, but certainly the risk factors are reduced.”
But while eating has its downsides, fasting is also a stress on the human body. It causes an increase in the levels of the stress hormone cortisol in your blood and activates the sympathetic nervous system, a process that is sometimes called the fight or flight response.
“These are all processes the body tries to liberate sugar from your body for the brain. These all have collateral damage on the body as well,” Professor Salis said.
The key, as in so many things when it comes to health, is moderation. Professor Salis advises to start by simply waiting until you truly feel hungry before you eat your next meal or snack.
Fasting and mental health
Your physical body isn’t the only thing that benefits from a break from eating. Fasting can also help you reset your relationship with food, according to psychologist Meredith Fuller.
Ms Fuller, who has taken part in fasting for health, not religious reasons, said she sees it as a way of respecting her own health and wellbeing.
To Ms Fuller, the mental health benefits of fasting come after food is reintroduced.
“Some people feel really out of control about food. They feel ‘I can’t say no, I can’t stop’. You learn that’s not the case, I have more choices in life than I think I do. What am I really craving right now?” she said.
“It’s about listening to our bodies, and it’s interesting how much our bodies really want to have healthy food.
“Your body has really got a wisdom of its own.”
For non-religious people, experiencing a fast can also give them more empathy for their friends who do fast for religious reasons, Ms Fuller said.
Planning to fast
But before you plunge headfirst into a fast, make sure that’s the best thing for your body.
Talk to your doctor about whether there are reasons you shouldn’t be doing it. Ms Fuller said you should also examine your motivations and what you’re hoping to get out of the fast. And be willing to call it if the fast doesn’t agree with your body.
“Be mindful of how you’re going,” she said.
“It’s important not to be rigid about any of these things.”
Professor Salis said it could help to try fasting in a community setting, the way people do for a religious fast.
Alongside the physical benefits, you also get the benefits of being part of something that connects you to the people around you.
Professor Salis, who is not religious, took part in Ramadan several years ago in preparation for a research project into the fast.
“As part of my research I vow not to ask anyone to do what I wouldn’t do myself,” she said.
Now she fasts for the holy month every year.
“I loved it. Eating together [after sunset], the challenge, ‘are we going to make it through today without food?'” Professor Salis said.
“If people are [fasting] in a meditation retreat or in Ramadan or Lent, there’s a bigger reason to doing the fast, you get that connectivity and that’s good for you.”