July 31, 2011
Chew More, Eat Less, Researchers Report
The act of eating may itself be a way to lose weight, according to a new study which claims that spending more time chewing your food more could cause you to eat less.
Writing in the American Journal of Clinical Nutrition, Jie Li and colleagues at the Harbin Medical University in China, discovered that those who chew their food 40 times instead of a typical 15 would consume approximately 12-percent fewer calories, according to a report on the research by Eric Schultz of Reuters Health.
In their research, the scientists recruited 14 obese men and 16 males of normal weight in order to study their chewing techniques. They fed them a pork pie and filmed them to see if there were any differences between the two groups. Next, they repeated the procedure twice, first instructing them to chew 15 times and then asking them to chew 40 times.
"Researchers found that when volunteers chewed for longer they consumed 11.9 percent fewer calories, regardless of whether they were slender or obese," Pat Hagan of the Daily Mail reported on Friday. "Blood tests taken 90 minutes after eating showed volunteers also had much lower levels of ghrelin when they had chewed each portion 40 times rather 15."
Ghrelin is a hormone that stimulates an individual's appetite.
The researchers also discovered higher levels of a second hormone, CCK, which is believed to reduce a person's appetite, Schultz reported. One of the researchers, co-author Shuran Wang, told Reuters in an email that both hormones could "represent useful targets for future obesity therapies."
University of Washington obesity expert Adam Drewnowski, who was not involved with the study, said that cutting calorie intake by 12-percent could theoretically cause an individual to lose 25 pounds per year. However, since the typical diet includes certain foods that are not chewed, and because it may be difficult for people to more than double the amount of times they chew each bite of food, "I am not sure that this is a viable obesity prevention measure."
"When you gulp down your food, you don't realize you're eating so much," Catherine Collins, chief dietician at London's St. George's Hospital--who, like Drewnowski, was not involved in the research, told Hagan. "But chewing for longer makes you more likely to notice the taste, smell and texture, which makes you more aware of what you're eating and how much."
On the Net:
- Harbin Medical University
- American Journal of Clinical Nutrition
- University of Washington
- St. George's Hospital (London)