Weight is an important indicator. There are a variety of standards to determine weight health, such as the height and weight of the site photographer, height 1.75m, weight 65kg, the calculation method is as follows: 1, the standard weight method, height centimeters minus 105 is the standard weight kilograms, one meter seventy-five minus 105, is 70kg, but the actual weight is 65kg. normal range of calculation is 70 minus 65 equals 5, 5 divided by the standard Weight is equal to minus 7%, and the difference between weight and standard weight is divided by the standard weight. If the resulting value is within plus or minus 10%, it belongs to the normal range. Plus or minus 20% up or down, respectively, belong to obesity or wasting; 2, BMI method, which is the body mass index. To videographer for example, the calculation method is weight kilograms divided by height meters squared, weight 65kg, height 1.75m, 65 divided by 1.75 squared equals 21.2, BMI result is 21.2kg/m^2, the normal range is 18.5-23.9kg/m^2, Asian body type if 24kg/m^2 or more is considered overweight, 28㎏/m2 or more is considered obese; 3 The waist circumference is mainly to determine whether it is visceral obesity, male more than 90cm, female waist circumference more than 85cm, all belong to visceral obesity; 4, body fat percentage. Many hospital nutrition department has body composition analyzer, through the instrument to analyze the body fat composition percentage. Obesity is defined as the amount of fatty tissue in the body exceeds the normal value. The result of the composition analysis, more than 30% for women and more than 25% for men, belongs to obesity. The specific case is a young girl who came to the nutrition clinic for consultation due to high blood sugar, age 22, height 1.5m, weight 36㎏, BMI is 16㎏/m2, because of lack of exercise, stay at home all day, muscle mass is very little, body mass percentage reaches 33%, more than 30%. Such a thin girl but obese, so the blood sugar is also high. Therefore, for chronic disease prevention, it is important to maintain a reasonable body weight, and at the same time to pay attention to strengthen exercise, so that the body fat percentage is limited to the normal range.