Do you think that you are fat? How fat are you? 你认为你胖吗?你有多胖？

　　If you are taller than your friends, you may be heavier than your friends. 如果你比你的朋友高，你可能比你的朋友重些儿。

　　So people divide your weight by your height. 所以人们用体重除以身高。

　　This is called BMI. 这就是所谓的体重指数

　　BMI mean body mass index. 体重指数指身体质量指数。

　　If your BMI is between 25 and 30, you are overweight. 如果你的BMI在25到30之间，你就是超重。

　　If your BMI is over 30, you are obese. 如果你的BMI超过30，你就属于肥胖。

　　How many people in the world are fat? 世界上有多少胖子？

　　At least, 1.6 billion people are overweight and 400 million adults are obese. 至少16亿人超重，4亿成年人过胖。

　　Being overweight or obese can cause serious diseases. 超重或过胖会导致严重的疾病。

　　So you have to eat healthy food and exercise regularly. 所以你必须吃健康的食物和经常锻炼。