At present, the internationally used indicator to measure the degree of fatness and thinness of the human body is body mass index, also known as body mass index, its abbreviation is BMI. it is calculated by dividing the weight by the square of the height, where the unit of weight is kilogram (kg) and the unit of height is meter (m), for example, an adult, his weight is 70kg, his height is 1.75m, then his BMI is 70 divided by 1.75, then divided by 1.75 equals 22.86. For example, if an adult weighs 70kg and is 1.75m tall, his BMI is 70 divided by 1.75, and then divided by 1.75 equals 22.86. When measuring weight indicators, if BMI is higher than 28, he is obese. Below 18, is underweight; between 18.5-23.9, belongs to the normal weight; and reached 24.0-27.9 belongs to overweight; then the body mass index in 18.5-23.9, is considered normal weight. If the usual life can be maintained to such a weight, is a relatively healthy body mass index, do not pursue too thin, but also can not be too fat, it is recommended that the usual aerobic exercise, such as running or yoga, in order to keep the weight within a standard range, which can ensure the health of the person, but also to achieve the beauty of the body type.