Why slow eaters may burn more calories

People have been advising others to chew their food well for a long, long time. In Ayurveda, a school of medicine founded in India some 7,000 years ago, slow and thorough chewing is considered essential to strong digestive health, helping to separate a food's indigestible components from necessary nutrients.

People also flocked to the notion—some, fanatically—in the U.S.