From wellness circles to religious celebrations, fasting is practiced by people from all walks of life and for a variety of reasons.
In fact, a recent US survey showed that 10% of Americans say they engage in some type of fasting regimen. That’s more than other popular eating habits like vegetarian (3%), Mediterranean-style (5%) and Keto (7%).
But are there actual health benefits to controlled calorie restriction? And how do people know if they should try fasting?
“There doesn’t seem to be any downside to intermittent fasting or … restricting any food you do to a certain number of hours each day,” National Geographic writer Fran Smith told ABC OTV.
Smith researched the science behind fasting for the publication’s new “Mind, Body, Wonder” series.
“You don’t have to eat three times a day. Or every three hours. No. We’re not babies. We don’t have to grow up,” Tzipi Strauss, a physician who founded a clinical center for healthy longevity in Israel’s Sheba Medical Center, Smith was told.
Decades of research show the upsides of fasting, Smith found. It is good for controlling blood sugar, promoting heart health, reducing excess weight, protecting against chronic disease and possibly delaying cognitive decline.
It may even help reverse the effects of aging.
“[Intermittent fasting] promotes this cellular process called autophagy, which is a fancy way of saying self-eating. Your cells are ingesting their own debris, and this allows the cells to replace themselves with really functional parts and work better,” Smith said.
Smith clarified that this research does not extend to fasting days, which can cause muscle loss and other problems.
But short-term intervals without food can work for almost everyone, even those with physically demanding lifestyles. One study showed that San Diego firefighters working during the grueling California fire season responded well when a fasting regimen was introduced.
“There were no performance issues, and, in fact, the food regimen showed all kinds of benefits … They really showed improvements in their heart function and in their sugar levels,” said Smith.
From skipping breakfast every day to changing eating patterns weekly, researchers have experimented with different types of fasting protocols — even on their own. The ideal ratio of how much to eat and when may exist, but science doesn’t yet know what it is.
“One of the really interesting things to me in this report is how many scientists in the aging and longevity space are actually fasting … They’re encouraged by the evidence,” Smith said. .
The bottom line: find out what’s right for you.
“Any fasting protocol is better than no fasting protocol,” says Smith.
In his reporting, Smith found that one researcher even designed a diet that tricks your body into thinking it’s fasting. Read more on NatGeo.com.
ABC OTV and National Geographic will explore health and wellness through four lenses: longevity, women’s health, brain health, and diet and nutrition. Using the latest in scientific research and information from experts in the medical field, we’ll answer questions about what’s important in the future of your health.
The Walt Disney Co. is the parent company of National Geographic Partners and the ABC station.