A recent study at a Japanese university found that chewing longer causes the body to use more energy. A Chinese study found that obese subjects chewed less than lean ones. A U.S. study found that intentionally chewing food more reduced the amount of food eaten without making people feel less satisfied.
It’s the latest suggestion for how to lose weight without the effort of eating differently or exercising more. But does it work?
At the turn of the 20th century, a man named Horace Fletcher made his fortune by advocating really thorough chewing. He wrote books, including Fletcherism: What It Is and gave lectures claiming that throughly chewing food made people stronger and thinner. It could also save money, he figured, since chewing each bite up to 100 times would lead to eating less. Fletcher claimed that fletcherizing allowed people to digest their food so much better that a smaller amount of food provided more nutrition.
Fletcherism was a popular fad of the 1890s and the early 20th century, followed by John D. Rockefeller (who explained it as, “Don’t gobble your food”), Mark Twain, and Thomas Edison were among the people who took up fletcherizing.
Fletcher made extreme claims for his method of eating, and it went out of fashion soon after his death.
Modern research results
One factor that gets in the way of a clear conclusion on the connection between increased chewing and weight loss is that chewing food more throughly tends to slow down eating.
People who eat faster tend to weigh more than those who eat more slowly. One reason for this is that it takes a while for the brain to realize that the body has had enough to eat. By eating quickly, people can continue eating after they have actually had a satisfying amount.
Eating highly processed food tends to take less time and less chewing than eating less processed food. How long does it take to down a serving of Chicken McNuggets compared with a broiled chicken breast, a baked potato, and a serving of broccoli? Those two meals contain about the same number of calories.
The studies listed at the top of this post included small numbers of people and small differences observed in their food consumption and diet-induced thermogenesis (the number of calories used to eat food). They don’t add up to magic effects from chewing more.
In addition to eating less processed food, another concept that correlates with slower eating is mindful eating.
Mindful eating is a matter of paying attention to your food, making sure to enjoy it thoroughly rather than rushing through the experience. The Mediterranean diet, widely agreed to be a particularly healthy way to eat, is not only focused on fresh, plant-rich foods, but also includes slower, more social eating. Enjoying a meal with friends and family is a more mindful experience than grabbing a fast food burger in your car.
It may be that this approach to food, rather than the mechanism of chewing more, is what leads to weight loss.