Chew food longer for weight loss

A new study finds that people who chew their food more take in fewer calories, which may help them control their weight.

Chewing food 40 times instead of a typical 15 times caused study participants to eat nearly 12 percent fewer calories, according to results published in the American Journal of Clinical Nutrition.

Li Jie and colleagues from Harbin Medical University in China gave a typical breakfast to 14 obese young men and 16 young men of normal weight to see if there were differences in how they chewed their food. The researchers also looked to see whether chewing more would lead subjects to eat less and would affect levels of blood sugar or certain hormones that regulate appetite.

In the study, the team found a connection between the amount of chewing and levels of several hormones that "tell the brain when to begin to eat and when to stop eating," co-author Wang Shuran says.

More chewing was associated with lower blood levels of ghrelin, a hormone that stimulates appetite, as well as higher levels of CCK, a hormone believed to reduce appetite.

These hormones may "represent useful targets for future obesity therapies ," Wang says, since regulating their levels may help people control their appetite.

The 12 percent reduction in calories eaten by the group who chewed their food 40 times in the study could potentially translate into significant weight loss.

If the average person cut their calorie intake by 12 percent, they would lose nearly 11 kg in one year, says Adam Drewnowski, director of the University of Washington Center for Obesity Research in Seattle, who wasn't involved in the study.