Researchers at Vanderbilt University found that laughter does burn calories -- but you would have to laugh for about 15 minutes a day, 365 days a year to lose just four pounds.

• 美国范德比尔特大学的研究人员发现：大笑可以消耗热卡，但每天笑15分钟，一年365天都是如此大笑，也仅仅会消耗4磅体内脂肪。