On the reference news, I saw a short article published in a Chilean newspaper entitled: Smile to lose weight. American scientists say that smiling every day can burn more than two kilograms of fat every year, because smiling can make the heart beat faster and make the muscles of all parts of the body fully active. Experts believe that laughter can become one of the best ways to deal with obesity. Researchers at Vanderbilt University in Tennessee, USA, found 90 volunteers, put them in two rooms, put comedy clips on video recorders, and observed how many calories they consumed when they laughed. In another room, the researchers asked volunteers not to talk or walk, but to sit on the sofa and stare at the TV screen. After analyzing the beating frequency of volunteers' hearts, the researchers found that participants consumed more energy 10% to 20% when laughing than during daily rest. So it is concluded that laughter can lose weight. I don't agree with this conclusion. Because in daily life, I see many optimists and people who love to laugh. They are not thin, just a little fat. People often say that the heart is broad and the body is fat. And some people who are sentimental and don't like to laugh are as thin as Lin Daiyu. Therefore, I think that a person's obesity is caused by many factors, and you must never choose any method that can consume heat to lose weight. As the saying goes, smile, ten years old, I agree. Smile to lose weight, I disagree. People often laugh every day, which is definitely good for their health. It's really hard to lose weight with a smile. I think doing exercise is more effective if you want to lose weight.