While it may not feel like a stride for a healthier body when Muslims brave 16-hour days of no food or water in Ramadan, some are emulating the practice outside of religious edicts as a way to jumpstart weight loss, increase lifespans, and stave off diseases.

Intermittent fasting has become an avenue to decrease calories for a specific period of time—perhaps just the morning, up to 24 hours, or several days—to give the body a chance to regroup. “When your body isn’t focused on digesting, it can focus on other things, like muscle repair, detoxification,” explains Alina Islam, a holistic nutritionist based in Toronto. Depriving yourself for extended periods also helps normalize hunger hormones and cortisol and burn fat, since there are no longer glucose stores for your body to dip into.

Valter Longo, professor of gerontology and biological science at the University of Southern California and director of the USC Longevity Institute, has released several studies on the effects of intermittent fasting. “We’ve known for a long time even simple organisms, when they’re starved, they live longer and healthier,” he says.

Longo’s work originally focused on the benefits to patients who had undergone chemotherapy. He found that extended periods of abstaining from eating helped the chemotherapy kill cancerous cells, protected against immune system damage, and activated stem cells.

His studies on mice that were deprived twice a month for four days show they increase their lifespan and have even reduced the symptoms of multiple sclerosis. He explains that when nutritional intake is limited, cells go into “shielded” mode, where they stop growing and invest more into protecting themselves. They are also killed off and regenerated into healthier cells.

Joel Fuhrman, physician, nutritional researcher, and author of several books, believes that humans, in general, have just been ingesting more than is necessary. After all, societies have experienced periods of time where they have run out of sustenance due to long winters or lack of crops because of inclement weather, he elucidates, and have proven that constant consumption isn’t vital. Excessive feasting raises hormones, he continues, and increases the risk of cancer. “It’s not consistent with our genes to eat. People in America, their diets are so low in nutrients and so excessive in calories, they become food addicts,” he expounds. “They start to feel weak if they’re not getting food.”

The symptoms, such as shaking, then start to resemble withdrawal and promote the false idea that weakness is coming from not eating, he says. “If you take really good care of your health, you don’t feel you have to eat all the time.”

Islam agrees. “People have screwed up the way we eat and the mentality around eating,” she expands.

There are several variations of intermittent fasting that have become popular. Longo’s vision is to have everyone do what he and his researchers call a “fast mimicking diet” of 800 to 900 calories once every three months for an average of five days. They developed the mimicking version with specially tailored ingredients because, while total deprivation from all food leads to many benefits, he doesn’t feel it should be taken on by anyone who isn’t being monitored. The mimicking version has similar effects but can be taken on without close supervision. He will do one himself a couple times a year to lose abdominal fat, which is not just a cosmetic concern for him; the fat collecting in the middle of the body can lead to many diseases.

Fuhrman advises at least a 13-hour window of no consumption overnight, which for him consists of an earlier dinner. He will take a few days out of the year to not eat for a longer time period when he feels he needs a tune up. Others will skip breakfast or have meals within a specific window later in the day. One popular version has been the 5:2 diet, which advocates normal dining habits for five days in a week and then cutting calories to one-quarter that amount for two.

Brad Pilon, author of Eat Stop Eat, will not have any meals for 24 hours at a time during the week. He will still drink water and other liquids but limits himself to items that have no calories. “The first time I tried fasting, I was amazed by the fact that it’s much easier than traditional dieting. I went 24 hours without having to go and find, measure, or count food or calories; it was a very liberating experience,” he explains. He also realized that previously he hadn’t been dining out of hunger; rather, he was eating out of habit. When he recognized that, he fixed a schedule. By limiting himself to 24 hours at a time once or twice a week, abstaining wasn’t a burden.

Many have a fear that they may lose muscle or wreck metabolism because they aren’t ingesting nutrients and protein, but Pilon disavows that notion. Longo agrees that muscle loss is not a concern. However, one issue can be that people binge after staying away from meals for so long. “When you finish your fast, you need to pretend that your fast never happened,” Pilon advises. “No compensation, no reward, no special way of eating, no special shakes, drinks, or pills. The minute you decide to stop fasting, you need to wipe the fast from your memory and eat the exact way you would normally eat at that specific time of the day.”

Nutritional content outside the deprivation windows is important, too. “Whatever lifestyle eating approach you take, it should be a whole food approach. You can’t just eat what you want,” Islam counsels. Fuhrman uses the G-BOMBS method: greens, beans, onions, mushrooms, berries, and seeds are items he advocates as anti-cancer agents.

Of course, anyone who takes on fasting should do the research and consult a physician about particular health concerns and the method being considered. Longo wants anyone who is intent on no nutritional intake for extended periods to do so at a clinic and be advised by a specialist. Fuhrman warns against anyone nursing a baby from taking on the endeavor and also cautions those with kidney or liver problems, cardiac arrhythmia, or taking certain medicines. Islam also recommends to her clients with adrenal exhaustion—whose adrenal glands are constantly pumping out hormones due to stress and who constantly feel exhausted—that they should focus on correcting that issue before taking on the practice.

However, those with diabetes or who are pre-diabetic can benefit from a decrease in nutritional intake, as it can stabilize blood sugar levels, as long as they are not dependent on medication. “A lot of people have insulin resistance,” says Islam. “When you stop eating throughout the day, you increase your insulin sensitivity. This is good for anyone who is on the cusp of being diabetic.”

While research has gone into the benefits of intermittent fasting, any fitness plan is not going to be one-size-fits-all. “The best thing to do is listen to your body and do intuitive eating when you’re hungry and stop when you’re full,” Islam advises. Plus, it may not be the best effort for someone who does not exercise regularly and is ingesting a solely processed menu. “Sort out your diet and lifestyle habits first,” she says. “When you’re doing a bit more exercise, that’s when you can start considering intermittent fasting.”

And although she warns against using Ramadan as a weight loss program instead of focusing on increasing faith, the tenets of normal consumption are found in the ways of Prophet Muhammad (Peace Be Upon Him), as he never ate to the point of gluttony. Many also use the month as a jumping off point for increasing spirituality throughout the year, and it can be used similarly for well-being.

“It’s like what people do with New Year’s or a 10-day cleanse,” Islam expands. “It’s all about what you do after those 10 days. Use Ramadan as that nudge.”

She has written a book about how to sustain a healthy diet during Ramadan so that the prospect of the summer fasts is easier to maintain, with advice such as limiting fried and processed products and increasing protein, fiber, and good fats. Not indulging after iftar (fast-breaking meal) and slowing down to a point where your body tells you it’s full is also a good rule to keep the month under control. However, “I think it’s also important to enjoy the treats that come with Ramadan,” she continues. “You don’t want to take the joy out of the month.”

Plus, unlike in Ramadan, where one of the reasons for deprivation is to empathize with the pain of the poor, Islam would recommend not stopping water intake if doing a fast solely for the sake of health.

If someone takes on the practice regularly, Longo adds, then they will recognize the effects it has and may adopt more healthy eating habits throughout the rest of the year. “If in three months, they’ve had 15 days of fasting, they really have an extended opportunity to understand they don’t need to eat bad food all the time,” he says. “They tend to maybe modify slowly their diet. Besides the effects of the fasting, which last for several months, then they have some behavioral changes.”

Nadia Malik holds a degree in journalism and is a former reporter for a Chicago-area newspaper. She has written for websites and publications and has also worked for several non-profit organizations