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Chew on This: More Mastication Cuts Calorie Intake by 12 Percent

The views expressed are those of the author and are not necessarily those of Scientific American.


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chewing on appleAbout a century ago, a new craze gripped the country’s health conscious: mastication. Chewing each bite of food precisely 32 times would help people control how much food they consumed—turning them from gluttons to epicureans—according to the early 20th-century dietician Horace Fletcher.

Among his many ardent adherents the tactic became known as "Fletcherizing." And Fletcher, in turn, has gone down in dietary history as "The Great Masticator," with the purported catch phrase: "nature shall castigate those who don’t masticate."

The theory, almost quaint in its specificity, soon fell out of popularity to be replaced by more familiar mid-20th-century forms of calorie-limiting diets.

But a recent study out of China provides a new look at the role that chewing might have in helping our bodies regulate the amount of food we take in—without having to consult calorie labels.

Jie Li of the School of Public Health at Harbin Medical University and colleagues found that both healthy-weight and obese men consumed fewer calories (about 12 percent less) at an unlimited half-hour meal when they chewed their food more.

Wolfing down a whole meal is often considered poor form, and previous research has linked slower eating habits with a healthier weight. The common wisdom is that eating more slowly gives the body more time to "feel full."

But as logical as it is that slower eating—coupled with or aided by more chewing—might be linked to consuming less, the specifics have yet to be fully worked out. One theory is that breaking food down in the mouth via more chewing allows the body easier access to nutrients, which would allow less consumption for the same nutritional benefit. But how does the body know when it should stop stuffing its face?

"Mastication apparently plays a role in the gut hormone profile, which consequently influences energy intake," the scientists wrote in their paper, published in July in the American Journal of Clinical Nutrition. Hunger is largely controlled by hormonal signals, including that from ghrelin, which spurs the feeling of hunger. The team found that when study participants chewed more, their ghrelin levels were consistently lower post-mealtime. It might be that the longer the body senses food in the mouth, the more ghrelin is released.

The study centered on a series of experimental breakfasts. Young men recruited for the study—16 of whom had body mass indexes (BMIs) of 18.5 to 23, which is considered lean for Asian men, and 14 of whom had BMIs of 27.5 or greater, which qualified them as obese for their demographic, sat down each morning to 300 grams of pork pie (a standard Chinese breakfast dish), with an option for additional servings. Researchers videotaped each subject eating and subsequently counted how many times they chomped down on each bite. The range across subjects was roughly 15 to 40 chews. During subsequent breakfasts, each subject was told to chew their bites either15 or 40 times.

Left to their own devices, all of the men had roughly the same preferred bite size (about 10 grams), but obese men ate each gram of food more quickly and with fewer chews than those who were leaner.

But after breakfasts during which they had to chew each bite 40 times, subjects consumed 11.5 percent fewer calories overall—and had lower concentrations of the hunger-piquing ghrelin hormone in their bloodstream afterward—than after morning meals during which they chewed each bite only 15 times.

So will more mastication help people slim down or keep the pounds from piling on in the first place? The researchers suggest "interventions for improved chewing activity" as a possible means for helping to stem obesity. The new study was too preliminary to tell whether The Great Masticator’s historical message could help rein in expanding waistlines for the long term. But the new findings at least give us something to chew on.

Image courtesy of iStockphoto/Lighthaunter





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  1. 1. scilo 6:04 pm 08/3/2011

    Science is like a small child who ‘discovers’ something.
    Anyone can read a book of yoga and find this ancient knowledge along with much more. It’s not just chewing that affects the body, there is also massaging the colon.
    Chewing many times (until liquid) is best. But don’t try this in a restaurant or at the family dinner table unless you don’t mind mindless criticism.
    Take heart! You need not do this with every bite. One or two good chewings will invigorate the stomach and digestive system by giving it the old saliva lift.
    Chewing a real wheat cracker to liquid while slowly breathing will get you high. Really, you will get the giggles, energy. It doesn’t work with GMO products.

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  2. 2. tharter 12:34 am 08/4/2011

    Yes, but science has also discovered that a lot of what passes for ‘ancient knowledge’ is actually ancient bunkum. For that matter a lot of what passes for CURRENT knowledge is bunkum too.

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  3. 3. jrtyrrell 1:45 pm 08/4/2011

    It’s really a pity that Yoga in it’s complete form only actually dates back to to the early 1960′s

    http://entertainment.timesonline.co.uk/tol/arts_and_entertainment/the_tls/article7172361.ece

    entertainment.timesonline.co.uk/tol/arts_and_entertainment/the_tls/article7172361.ece

    But then again as long as it sounds old people will believe anything ;)

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  4. 4. ravenrose 2:33 pm 08/4/2011

    The body is a marvelously well regulated thing under most circumstances. What the researchers are not taking into account is that people will get more REAL calories from the food they eat when they chew it better. Less well chewed food is not as well digested. I’m quite sure they EAT less “calories” as measured by the researchers because the calories they are actually getting from their food remains the same. They stop eating when they get to the same point. so this would be a way to cut food expenditures by using the food we buy more efficiently, but it won’t cause people to lose weight.

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  5. 5. freebesthealth 10:19 am 08/5/2011

    Though this aspect is newly getting attention, in indian science of ayurveda there is detailed discussion as to how to eat , when to eat, how much to etc. etc. So eating the food by chooing it maximum time definitely is a good habit leading to healthy life. It reduces the intake of food and also helps digestion quite easily.

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  6. 6. freebesthealth 10:55 am 08/5/2011

    chewing the food more number of times has a great bearing on digestion and health related to it. It is therefore highly recommended in ancient indian science of Ayurveda,though this aspect is getting more attention now a days.

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  7. 7. Sean McCann 9:56 am 08/8/2011

    Yeah, ancient ayurvedic practice also discovered the cause of and cure for cholera…Oh wait, it didn’t.

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