Excerpt of Mary Roach’s Gulp: How many times should you chew a bite of food?

The Health Fad That Had Henry James, Franz Kafka, and Arthur Conan Doyle Chewing Like Lunatics

The Health Fad That Had Henry James, Franz Kafka, and Arthur Conan Doyle Chewing Like Lunatics

Health and Science has moved! You can find new stories here.
What to eat. What not to eat.
April 10 2013 12:00 AM

How Many Times Should You Chew Your Food?

For maximum efficiency, according to one of the original crackpot health fads, hundreds and hundreds of times.

Horace Fletcher, American health-food faddist, September 1908.
Horace Fletcher, American health-food faddist

Courtesy of Library of Congress/Wikimedia Commons

There is a point at which efficiency crosses over into lunacy, and the savings in money or resources cease to be worthwhile in light of the price paid in other ways. Horace Fletcher, the self-dubbed economic nutritionist, danced around that point his whole career. What amazes me is the degree to which he was taken seriously. Fletcher was the instigator of a fad for extremely thorough chewing. We are not talking about British Prime Minister William Gladstone’s 32 chews per bite. We are talking about this: “One-fifth of an ounce of the midway section of the young garden onion, sometimes called ‘challot,’ has required 722 mastications before disappearing through involuntary swallowing.”

Fletcher in the flesh did not, by most accounts, appear to be the crackpot that that sentence suggests. He is described as cheerful and charming, a bon vivant who liked to dress in cream-colored suits that set off his tan and matched his snowy hair. He believed in physical fitness, clean living, good manners, fine food. Fletcher’s well-lubed charm and connections served him well. Generals and presidents took up “Fletcherizing,” as did Henry James, Franz Kafka, the inevitable Sir Arthur Conan Doyle. In 1912, around the fad’s peak, Oklahoma Sen. Robert L. Owen penned a proclamation—a draft of which resides among the Fletcher papers at Harvard—urging the formation of a National Department of Health based on the principles of the Fletcher system. Sen. Owen declared excessive chewing a “national asset” worthy of compulsory teaching in schools. Not long after, Fletcher snagged a post on Herbert Hoover’s World War I Commission for Relief in Belgium.

Listen to Mary Roach's recent author talk at Politics & Prose bookstore

It was not mere charisma that landed him there. Fletcherism held a good deal of intuitive appeal. Fletcher believed—decided, really—that by chewing each mouthful of food until it liquefies, the eater could absorb more or less double the amount of vitamins and other nutrients. “Half the food commonly consumed is sufficient for man,” he stated in a letter in 1901. Not only was this economical—Fletcher estimated that the United States could save half a million dollars a day by Fletcherizing—it was healthier, or so he maintained. By delivering heaps of poorly chewed food to the intestine, Fletcher wrote, we overtax the gut and pollute the cells with the by-products of “putrid bacterial decomposition.”

Practitioners of Fletcher’s hyperefficient chewing regimen, he wrote, should produce one-tenth the bodily waste considered normal in the health and hygiene texts of his day. And the waste was of a superior quality—as demonstrated by an unnamed “literary test subject” who, in July 1903, while living in a hotel in Washington, D.C., subsisted on a glass of milk and four Fletcherized corn muffins a day. It was a maximally efficient scenario. At the end of eight days, he had produced 64,000 words and just one bowel movement.


“Squatting upon the floor of the room, without any perceptible effort he passed into the hollow of his hand the contents of the rectum,” wrote the anonymous writer’s physician in a letter printed in one of Fletcher’s books. “The excreta were in the form of nearly round balls,” and left no stain on the hand. “There was no more odour to it than there is to a hot biscuit.” So impressive, so clean, was the man’s residue that his physician was inspired to set it aside as a model to aspire to. Fletcher adds in a footnote that “similar [dried] specimens have been kept for five years without change,” hopefully at a safe distance from the biscuits.

At one chew per second, the Fletcherizing of a single bite of shallot would take more than 10 minutes. Supper conversation presented a challenge. “Horace Fletcher came for a quiet dinner, sufficiently chewed,” wrote the financier William Forbes in his journal from 1906. Woe befall the non-Fletcherizer forced to endure what historian Margaret Barnett called “the tense and awful silence which ... accompanies their excruciating tortures of mastication.” Nutrition faddist John Harvey Kellogg, whose sanatorium briefly embraced Fletcherism, tried to re-enliven mealtimes by hiring a quartette to sing “The Chewing Song,” an original Kellogg composition, while diners grimly toiled. (I managed to track down only one stanza. It was enough. “I choose to chew/ because I wish to do/ the sort of thing that Nature had in view/ Before bad cooks invented sav’ry stew/ When the only way to eat was to chew, chew, chew.”)

I searched in vain for film footage, but Barnett was probably correct in assuming that “Fletcherites at table were not an attractive sight.” Franz Kafka’s father, she reports, “hid behind a newspaper at dinnertime to avoid watching the writer Fletcherize.” How did this unsightly and extreme practice come to be taken seriously? Fletcher, an assiduous networker and general gadabout, began by getting the scientists on his side. Though he had no background in medicine or physiology, he collected friends who did. While living in a hotel in Venice in 1900, Fletcher befriended the hotel doctor, Ernest van Someren. Originally more interested in Fletcher’s stepdaughter than in his theories, van Someren was eventually won over (or worn down—Fletcher’s letters, though gaily phrased, amount to lengthy harangues). Van Someren gussied up Fletcher’s theories with invented medical jargon like the “secondary reflex of deglutition.”

As only a hotel doctor has time for, van Someren set to work gathering the data both men knew Fletcher would need to gain approval in scientific circles. Fletcher had experimented on himself, but these efforts were unlikely to convince the research community. He had simply weighed and recorded each day’s bodily input and output for both himself and “my man Carl,” over the course of a bicycle trip through France. As Fletcher described the scenario, in a letter to one of his benefactors in 1900, Carl was “a young Tyrolean ... in national costume” hired to carry the scale and “wheel my bicycle up the grades and be generally useful.”


Van Someren presented a paper at a meeting of the British Medical Association in 1901, and again at the International Congress of Physiology. Skeptical but intrigued, well-placed scientists at London’s Royal Society and at Cambridge University and Yale’s Russell Chittenden undertook follow-up studies, with mixed conclusions. In 1904, 13 lads of the Hospital Corps Detachment of the U.S. Army were taken away from their nursing duties for six months to serve as guinea pigs in a test of Fletcher and Chittenden’s low-calorie, low-protein, super-mastication regimen. Here there was no strapping lad in knickers and feathered felt hat to do the weighing and tidying up. The men’s work began at 6:45 a.m. with an hour and a half of “duties about the quarters, such as ... assisting in measurement of urine and faeces and transportation of the same to the laboratory; cleansing of faeces cans and urine bottles, etc.”

Chittenden claimed to have evidence that the Fletcher system enabled a man to get by on two-thirds the calories and one-half the protein recommended by the current nutrition guidelines. Though the claims were roughly critiqued and largely dismissed by other scientists, they struck a chord with victualers: military officers and others whose jobs entailed feeding hungry hordes on limited budgets. In the United States and Europe, administrators at workhouses, prisons, and schools flirted with Fletcherism. The U.S. Army Medical Department issued formal instructions for a “Method of Attaining Economic Assimilation of Nutriment”—aka the Fletcher system. (“Masticate all solid food until it is completely liquefied,” begins the familiar refrain.) In 1917, Chittenden   became a scientific advisor to Herbert Hoover, then the head of the U.S. Food Administration. Fletcher, living in Belgium during World War I and already chummy with the U.S. ambassador there, parlayed these two connections into his gig as an “honorary alimentary expert” for Hoover’s relief commission. Together, he and Chittenden did their best to convince Hoover to make Fletcherism part of U.S. economic policy, thereby justifying a two-thirds reduction in the amount of civilian rations shipped overseas. Hoover sagely resisted.

Fletcher’s true colors could occasionally be seen through the seams of his cream-colored suits. After bragging, in a 1910 letter, that a family of five could save enough money to furnish a five-room flat in 15 months by Fletcherizing, he adds, “Of course, the furnishings must be of the simplest sort.” This from a man who lived for years in a suite at the Waldorf Astoria. He summed up his policies at the end of the letter: “Expert economics coming to the assistance of ambitious unintelligence.” Let them chew cake.

In 1979, a pair of Minneapolis researchers put Fletcherism to the test. They brought 10 subjects to the local Veterans Administration hospital and purchased some peanuts and jars of peanut butter. The subjects first ate a diet in which almost all the fat came from peanuts. The peanuts were then swapped out for the peanut butter—an aesthetically acceptable stand-in for excessively chewed peanuts. The subjects’ “digestion ash,” as Fletcher liked to call excrement, was then analyzed to see how much of the peanut fat was leaving the body unabsorbed.


“ ‘Nature will castigate those who don’t masticate’ may hold some truth,” concluded the paper, which appeared in the October 1980 issue of the New England Journal of Medicine. On the whole peanut diet, the subjects excreted 18 percent of the fat they’d consumed. When they switched to peanut butter, only 7 percent escaped in their stool.

But peanuts are hardly representative of the average food. Everyone knows—via “visual observation of stool samples,” to use the New England Journal of Medicine’s way of saying “a glance before flushing”—that chunks of peanuts make their way through the alimentary canal undigested. Nuts are known for this. Peanuts (and corn kernels) are so uniquely and reliably hard to break down that they are used as “marker foods” in do-it-yourself tests of bowel transit time—the time elapsed between consumption and dismissal. (The human digestive tract is like the Amtrak line from Seattle to Los Angeles: Transit time is about 30 hours, and the scenery on the last leg is pretty monotonous.) 

Peanuts are the food singled out for this trait by Martin Stocks, business development manager for the Model Gut, a computerized tabletop digestive tract that can be hired out for absorption studies. I had contacted Stocks to see if it might be possible to engage the Model Gut for a test of Fletcherism. It was, but would “likely run into the $10,000 to $20,000 range.” Stocks’s opinion was that with a few recalcitrant foods—here he singled out nuts and rare or raw meat—extensive mastication (chewing) might make a small difference in how much energy and nutrients are absorbed, but that it was “unlikely to have a dramatic effect on one’s overall nutritional intake.”

Stocks passed my email along to Model Gut senior scientist Richard Faulks. Faulks was dismissive not only of extreme chewing, but also of the related fad for blenderizing to increase the accessibility of nutrients. Its true saliva carries an enzyme that breaks down starch, but the pancreas makes this enzyme too. So any digestive slack caused by hasty chewing would be taken up in the small intestine. The human digestive tract has evolved to extract the maximum it can from the food ingested, Faulks said, and that is probably all it needs. “Nutritional science is dogged by the idea that if some is good, more is better,” he said, “and this has led to the belief that we should endeavor to extract as much as possible of whichever fashionable component is in vogue. This is to ignore evolutionary biology and the imperative of survival.” He pretty much ran Horace Fletcher through the Model Gut.

One thing to be said in favor of thorough chewing is that it slows an eater down. This is helpful if that particular eater is trying to shed some weight. By the time his brain registers that his stomach is full, the plodding 32-chews-per-bite eater will have packed in far less food than the five-chews-per-bite wolfer. But there’s thorough and there’s Fletcher. Chewing each bite, say, 100 times, Faulks said, could have the opposite effect. It would lengthen the meal so radically that the stomach could have time to empty the earliest mouthfuls into the small intestine, while the last mouthfuls are still on the table. Thereby making room for more. Fletcherizers’ meals could conceivably be so interminable that by the time they finally cleared their plate and set down their napkin, they’d already be feeling peckish again.

Not to mention, the morning’s half gone. “Who has time for this?” was the reaction of Jaime Aranda-Michel, a gastroenterologist with the Mayo Foundation, when I called to ask him about Fletcherizing. “You’re going to spend all day just having breakfast. You will lose your job!”

Adapted from Gulp: Adventures on the Alimentary Canal by Mary Roach. Copyright © 2013 by Mary Roach. With permission of the publisher, W.W. Norton & Company, Inc.