Fasting Before It Was Trending: The Pioneers Who Used It First

Today, intermittent fasting is discussed in medical journals, featured in bestselling books, and practiced by tens of millions of people worldwide. But the idea that voluntarily abstaining from food could improve — and even restore — health is not a modern discovery.

Long before controlled clinical trials, macros, and fasting apps, a small group of unconventional thinkers were documenting the effects of fasting on the human body, arguing passionately for its therapeutic potential, and frequently being ridiculed for it. Their stories are worth knowing.

Historical Context: Fasting in the Victorian and Edwardian Era

By the late 19th century, the dominant medical model centred on pharmaceutical intervention, surgical treatment, and highly specific dietary prescriptions. Fasting — deliberately eating nothing — was considered either a religious practice, a dangerous eccentricity, or both. The idea that a body deprived of food could heal itself struck most mainstream physicians as medically illiterate.

This is the context in which the early fasting pioneers operated. They were working against institutional medicine, against popular opinion, and in the absence of the biochemical language that would later explain why fasting worked. What they had was observation, tenacity, and — in some cases — their own dramatically improved health.

Upton Sinclair: The Journalist Who Fasted His Way Back to Health

The most influential populariser of fasting in the early 20th century was Upton Sinclair, best known for his muckraking novel The Jungle (1906), which exposed conditions in the American meatpacking industry. But Sinclair had another cause that he pursued with equal passion: fasting as medicine.

By his own account in his 1911 book The Fasting Cure, Sinclair had spent approximately $15,000 over six to eight years on physicians, surgeons, sanatoriums, and drug treatments for a collection of persistent complaints — chronic headaches, insomnia, and what he described as persistent nervous exhaustion. Nothing worked permanently.

After reading about fasting, Sinclair attempted his first extended fast: twelve days on water alone, with daily bathing and rest. The results astonished him. The headaches that had defined his existence for years disappeared. His energy and mental clarity reached levels he hadn't experienced in a decade.

He fasted a second time — another twelve days — and this time continued his intellectual work throughout. He walked four miles every morning and described his mind as "so active I read and wrote incessantly."

Sinclair then did what journalists do: he wrote about it. A magazine article in Cosmopolitan generated between 600 and 800 reader letters from people who had tried fasting after reading his account. He compiled their reports — 277 fasting episodes from 109 people — into his book The Fasting Cure, published in 1911 by Mitchell Kennerley.

The medical establishment's response was predictably hostile. Sinclair was described in the New York Times as a "shallow and unscrupulous sensationalist." Of the hundreds of letters he received, only two came from physicians.

This hostility, Sinclair argued, was not entirely coincidental. Fasting was free. Doctors charged money. A therapy that anyone could use at home, at no cost, did not sit comfortably within a medical system built on prescriptions and fees.

Bernarr Macfadden: Physical Culture and the Healing Fast

Before Sinclair, there was Bernarr Macfadden — a figure so flamboyant that he makes Sinclair look reserved.

Macfadden was a physical culture promoter, publisher, and showman who built a media empire in the early 20th century on the principle that most human disease was caused by poor diet, insufficient exercise, and what he called "medinicide" — the overuse of drugs and surgery. He founded Physical Culture magazine in 1899 and ultimately built a publishing business worth millions.

Central to Macfadden's philosophy was the therapeutic fast. He ran institutions — most notably in Chicago — where people paid to fast under supervision, sometimes for extended periods. His 1923 book Fasting for Health documented cases including fasts of 90 days, and he advocated periodic fasting as routine health maintenance for everyone.

Macfadden's methods were eccentric and his claims sometimes extravagant, but his core insight — that the digestive system benefits from periodic rest, that the body has self-healing capacity when properly supported, and that food quality matters as much as quantity — has aged considerably better than many of the pharmaceutical prescriptions of his era.

Sinclair referenced Macfadden's work and cited cases that had occurred at his institutions. The two figures represented the same counter-cultural health movement, though from different starting points: Sinclair the intellectual journalist, Macfadden the physical culture showman.

Dr. Edward Hooker Dewey: The Breakfast-Skipping Physician

Less famous than either Sinclair or Macfadden, but arguably more scientifically careful, was Dr. Edward Hooker Dewey — an American physician who published The No-Breakfast Plan in 1900.

Dewey's proposition was simple: the morning is not the right time to eat. His clinical observation, developed over decades of practice, was that patients who ate a substantial breakfast were often sicker than those who didn't. He began recommending that sick patients skip breakfast entirely and eat only when genuinely hungry, and found consistent improvement across a wide range of conditions.

Dewey's "no-breakfast plan" was the precursor to what we would now call time-restricted eating. He wasn't advocating multi-day fasting — his intervention was simply compressing the eating window by eliminating the first meal of the day. His clinical reasoning anticipated the modern understanding of insulin cycles and circadian eating patterns by more than a century.

Sinclair cited Dewey's work in The Fasting Cure and credited him as one of the early medical voices arguing that less food, more strategically timed, was often better medicine than more food at regular intervals.

Dr. Linda Burfield Hazzard: Controversy at the Extreme

No account of fasting's early champions would be complete without acknowledging its most controversial figure: Dr. Linda Burfield Hazzard of Seattle, Washington.

Hazzard was a practitioner who used fasting — often extended fasting — as her primary therapeutic tool, and who ran a fasting sanitarium on Olalla Island, Washington, called "Wilderness Heights." She published a book, Fasting for the Cure of Disease (1908), and treated many patients over several decades.

The problem was that several of her patients died. Hazzard was convicted of manslaughter in 1912 after a British patient died under her care. She maintained throughout that the patient had arrived with a terminal condition, not that the fasting had caused death.

Sinclair included a letter from Hazzard as an appendix in The Fasting Cure, presenting her as a defender of therapeutic fasting against unfair prosecution. Modern historians have taken a more complicated view. Hazzard's story represents both the potential and the risk of fasting undertaken without proper monitoring — a cautionary chapter in the history of the practice.

What Science Would Later Confirm

When Upton Sinclair described his experience of the "morbid matter" being consumed before healthy tissue during a fast, he was groping toward a concept that wouldn't be properly described for another 75 years: autophagy. The 2016 Nobel Prize in Physiology or Medicine was awarded to Yoshinori Ohsumi for his work characterising the mechanisms by which cells dismantle and recycle their own damaged components — exactly the process Sinclair was observing and poorly explaining in 1911.

When Sinclair described the tongue clearing during a fast as a signal that detoxification was complete, he was observing a real phenomenon — the cessation of metabolic byproduct excretion through mucosal surfaces — without the biochemical language to explain it.

When Macfadden insisted that periodic digestive rest was essential to health, he was anticipating research on gut microbiome regeneration, intestinal permeability repair, and mucosal immune recovery that would emerge a century later.

This doesn't mean everything these pioneers wrote was correct. Sinclair's "fermentation theory" of disease, while capturing something real about the relationship between diet and inflammation, overstated the case. Macfadden's claims were frequently unverifiable and sometimes irresponsible. Hazzard's outcomes speak for themselves.

But as historical documents of human experimentation, observation, and advocacy, these early accounts deserve more attention than they typically receive. The pioneers who championed fasting before the science existed to support them were, in their imperfect way, pointing toward something real.

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Frequently Asked Questions

Q: Who was the first person to promote fasting as medicine? A: Therapeutic fasting has ancient roots — in religious traditions and early Greek medicine — but its modern champions in the late 19th and early 20th centuries include Dr. Edward Hooker Dewey, Bernarr Macfadden, and Upton Sinclair. Each approached it from a different direction: medical practice, physical culture, and personal health journalism respectively.

Q: What did Upton Sinclair's book say about fasting? A: In The Fasting Cure (1911), Sinclair documented his own two twelve-day fasts and the reports of 277 fasting episodes collected from readers. He argued that most chronic disease was caused by toxins from overfeeding, and that fasting allowed the body to cleanse and repair itself. He was largely rejected by the medical establishment of his time.

Q: Were the early fasting pioneers taken seriously? A: Not by mainstream medicine. Upton Sinclair was publicly dismissed as a sensationalist. Macfadden was considered a health eccentric. Dewey's no-breakfast plan was widely ignored. Their vindication has come slowly, through the accumulation of research over the following century.

Q: Is the history of fasting scientifically documented? A: The most rigorous early documentation came from scientists rather than advocates. Francis Gano Benedict's 1915 study at the Carnegie Institution of Washington, A Study of Prolonged Fasting, subjected a 31-day fast to the most rigorous scientific measurement available at the time — a counterpart to the popular accounts that Sinclair and others produced.

Q: What did these early pioneers get right? A: Quite a lot, in broad strokes. The idea that digestive rest has healing properties is now supported by research on gut microbiome repair, intestinal permeability, and inflammatory reduction. The observation that mental clarity improves during fasting maps onto modern BDNF and ketone research. The principle that food quality — not just quantity — drives health outcomes has become a cornerstone of modern nutrition science.

This article draws on historical research from 1911 and is for informational purposes only — not medical advice.

Sinclair, U. (1911). The Fasting Cure. Mitchell Kennerley.

Fasting Before It Was Trending: The Pioneers Who Used It First