Chew More, Weigh Less: Slower Mastication Linked To Lower Calorie Intake
Chewing your food more thoroughly could help you lose weight, according to a new study. Researchers at Iowa State University have discovered that increasing the number of times you chew may lower your total caloric intake during a meal. The findings add further support to the theory that slower eaters have healthier weights.
The study, which is published in the Journal of the Academy of Nutrition and Dietetics, sought to quantify the influence of chewing rate on food intake. Specifically, the researchers wanted to find out whether more rigid mastication can help an individual restrict calories and, consequently, shed weight. "The study reinforces the benefits of taking time to chew food well and enjoy the variety of textures and flavors in our meals," Constance Brown-Riggs of the Academy of Nutrition and Dietetics told Reuters.
To find out, the researchers first enrolled normal weight, overweight, and obese people in a preliminary eating experiment. Participants were asked to consume five portions of pizza rolls and asked how many times they chewed each piece. From the results, the researchers recruited a final study group comprised of 16 normal weight, 16 overweight, and 15 obese subjects.
On three separate occasions, these 47 subjects were given 60 pizza rolls and were asked to eat until they were full. During one session, the subjects were asked to chew their food as many times as they did during their first visit –– their “baseline” chewing number. During another, they were asked to increase this number by 50 percent. Finally, they were asked to double their baseline chewing number.
The research team found that increased chewing did indeed correspond to a lowered caloric intake. When they increased their baseline chewing by 50 percent, the subjects ate about 10 percent less food, or 70 fewer calories. When they increased it by 100 percent, they ate 15 percent less food and 112 fewer calories. "Increasing the number of chewing cycles before swallowing can reduce food intake and increase satiety," said co-author James Hollis. “However, it is not clear if this is a practical approach to weight management."
According to some experts, the results may be attributed to the fact that slower eaters give their bodies more time to “realize” that they are full. “It takes about 20 minutes for the brain to signal your stomach that you're full," Brown-Riggs explained. "Fast eaters can consume a large amount of food within that 20-minute period resulting in more calories, which can lead to overweight or obesity. This may be why participants in this study reduced their food intake. Increasing the number of chews increased the meal duration."
Today, an estimated one-third of American adults are obese. The condition is associated with an increased risk of developing heart disease, stroke, type 2 diabetes, and certain cancers. The Centers for Disease Control and Prevention estimates that the annual medical cost of the epidemic is $147 billion.
Source: Yong Zhu, James H. Hollis. Increasing the Number of Chews before Swallowing Reduces Meal Size in Normal-Weight, Overweight, and Obese Adults. Journal of the Academy of Nutrition and Dietetics. 2013.