Humans were forced into periods of fasting throughout our evolution due to scarcity of resources, punctuated by brief periods of feasting. Interestingly, since the more recent development of farming and food refrigeration, humans have continued to fast, often for strange, diverse, and powerful reasons.
You’ve no doubt heard of fasting for religious or cultural reasons, and more recently you’ve probably heard about intermittent fasting and time-restricted eating methods as weight loss tools popularized by celebrities and friends alike.
But the practice of fasting has been around for hundreds of thousands of years. Early humans had to hunt or forage for food after waking up with the sun, so they likely would have inadvertently practiced a “circadian fast” during daylight hours, or perhaps a longer time-restricted eating fast depending on how long it took to acquire food. If no food sources were available, they likely practiced more extended periods of involuntary fasting.
Here, learn more about the curious and fascinating history of fasting from centuries ago and why it’s become popular in modern times.
In American culture, food is constantly available for many of us.
“Fasting sits neatly at the intersection of powerful trends in American culture: the longstanding celebration of self-mastery and restraint around food, and a newer impulse to ‘optimize’ every aspect of one’s life,” saysNatalia Mehlman Petrzela, Associate Professor of History at The New School, co-host of the Past Present Podcast. “The religious language—’fasting’—also elevates it to a pursuit that feels more noble than calorie counting.
“Our contemporary diet culture is based on the idea that restraining oneself from partaking in an abundance of available food is a virtuous act,” says Petrzela. “As food became cheaper and more widely available with industrialization, resisting highly-caloric food is a way of showing class and status rather than partaking in something now so widely available.”
“Food insecurity in the U.S. is not only about hunger, but lack of agency over one’s food, whether that’s insufficient resources to buy healthful food, eat regularly, and create wholesome portion-controlled meals,” she says. “Fasting deliberately is less a form of ‘voluntary starvation’ and more a way of demonstrating control over one’s eating and food, which in a food-insecure nation is a privilege, especially when that agency is employed not to eat,” Petrzela says.
It is a privilege to be able to pick and choose when you eat and what you eat when breaking a fast. Amongst the high-status Americans who openly discuss using intermittent fasting to maintain their figures include the following celebrities: Jennifer Aniston (16:8), Kourtney Kardashian (24-hour fast or 16:8), and Jimmy Kimmel (5:2 diet). “I think intermittent fasting has become more popular lately because of attention from celebrities,” says Krista Varady, Ph.D., is a Professor of Nutrition at the University of Illinois, Chicago, author of The Every Other Day Diet, “People are tiring of really complicated, expensive diets. They want something simple.
“Part of the appeal of fasting is also getting to eat without restriction during certain hours, so that notion of control over one’s food applies not only to being able to resist but also to choosing to eat with abandon,” says Petrzela. (Here’s how to fast during the holidays.)
While some people practice fasting to cleanse and achieve a spiritual state and this has been a regular practice for hundreds of years, deliberately using fasting and intermittent fasting in order to lose weight is a modern practice.
“We think interest came out of religious fasting,” says Varady, who studied calorie restriction during her post-doctorate years. “I think, probably the closest thing to time-restricted eating and similar interest in this was Ramadan fasting, where people fast from sunup to sundown. Intermittent fasting is usually the reversal of that practice.
“I noticed that people really struggled when they were trying to reduce energy intake every day, just because they have to be hypervigilant about monitoring calories,” she says. “I thought, well, do people really have to diet every day to lose weight? Or, can you just undergo kind of heavier periods of restriction? Perhaps just a couple of days a week, you’ll fast and then give yourself a couple of days off in between. We were the first lab to look at whether or not people can use intermittent fasting for weight loss.” They also conducted the first study on alternate day fasting.
Intermittent fasting (IF) is the umbrella term for many different methods. There’s alternate day fasting (ADF), where people eat 500 calories or less every other day and have normal food consumption every other day (some people do a water fast instead of 500 calories). Then there’s the 5:2 diet, with two 500-calorie days per week and five days of normal calorie intake. “Also, there’s time-restricted eating, which is definitely the most popular form right now,” says Varady. People usually eat during an 8 or 12-hour window and water-fast for the rest of the day (or more typically overnight).
“The nice thing with restricted eating is that you can follow the diet without needing to change what’s in your pantry,” says Varady. “Time-restricted feeding is probably getting more popular because people find it easier to do. You don’t have to count calories; all you have to do is pick a time window for eight hours if you’re following a 16:8 plant,” says Varady. “Pick the time frame for the day and stick to that. Studies have shown that people naturally eat about 300 to 500 calories less just by watching the clock with this practice.”
Muslims practice fasting during the holy month of Ramadan, from sunup to sundown. Catholics fast during Lent on Ash Wednesday, Good Friday, abstain from eating meat on Fridays, and usually give up something throughout the 40 days. While there are six fasting days in the Jewish calendar, the most popular fast is on their holiest day of the year, Yom Kippur, which involves fasting from sundown to sundown in either September or October to observe the “Day of Atonement.”
Fasting in Hinduism is an optional practice believed to purify the body and mind to achieve “pure grace.” Fasts followed by Hindus range from light fasting—perhaps cutting out meat or eliminating one meal a day—to longer-term fasts, which might involve fasting during the day or one day a week.
Perhaps the most well-known ancient practice of fasting for health was utilized by the ancient Greek physician, Hippocrates. The “father of medicine” lived from 460 B.C. to 375 B.C. and recommended patients abstain from food and drink to cure ailments as it was believed that fasting helped the body recover naturally from illnesses.
Beyond that, better understandings of fasting came about in the 19th century as studies were conducted on animals and humans. American physician Dr. Edward H. Dewey preached the health benefits of fasting and developed a “no breakfast” approach to health and weight loss in the mid-to-late-1800s. Throughout the 20thcentury, various fasting methods were used to treat chronic ailments. Some physicians in the early 1900s used fasting to treat epilepsy, diabetes, and obesity. Early methods practiced by doctors involved modified fasting, which included caloric intake of 200 to 500 calories daily (early 5:2 diet, anyone?), or eating only 800 calories a day to induce weight loss.
Another early adopter of fasting for health reasons was Paul C. Bragg, N.D., Ph.D., Dr. Bragg used water fasts in the early 1900s to purify the body, rest the digestive organs, improve heart health, and live longer. People believed fasting was just “crazy talk,” but Bragg continued to teach about the healing effects of fasting in his lectures.
Bragg and his daughter, Patricia Bragg, N.D., Ph.D. wrote The Miracle of Fasting: Proven Throughout History for Physical, Mental and Spiritual Rejuvenation, published in 1970. (You might recognize Bragg’s name from Bragg Apple Cider Vinegar, founded by Paul Bragg in 1912.) The Braggs Healthy Lifestyle plan recommends 24-to 36-hour distilled water fasts weekly for longevity and health benefits—and 92-year-old Patricia still practices those fasts!
Today, quite a few research facilities are dedicated to studying the health benefits of fasting, like the Salk Institute for Biological Studies, whose research team is led by Satchidananda Panda, Ph.D. The Salk Institute lab studies the effects of the circadian clock on the body’s systems and discovered that confining caloric consumption to an 8- to 12-hour period might stave off high cholesterol, diabetes, and obesity.
Read the full article on Fasting.com.
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