Body mass index is the percentage of weight in kilograms divided by the square of height in meters. It is a common international standard to measure the degree of fatness and health of human body. When we need to compare and analyze the influence of a person's weight on the health of people of different heights, the body mass index is a neutral and reliable indicator. If the person with 180cm is 80 kg, the calculation method is 80÷ 1.8? =24.69。 That is body mass index = weight/(height) 2.

Calculation method recommended by the World Health Organization:

1, male: (height cm-80) × 70 = standard weight?

2. Female: (height cm-70) × 60% = standard weight.

Standard weight plus or minus 10% is normal weight, standard weight plus or minus 10% ~ 20% is overweight or underweight, and standard weight plus or minus 20% is obesity.

Extended data:

Overweight weight 10% ~ 20% leads to prolonged life. Professor stiles, an American gerontologist, found that among people over 70 years old in California, those who exceed the standard weight 10% ~ 20% have the lowest mortality rate. When the weight is too low or too high to 30%, it is easy to cause diseases and affect life expectancy.

The reason why obese people live longer is that the subcutaneous fat layer of obese people is thicker, and their cold resistance and disease resistance are stronger than those of ordinary people, and they can withstand the "torture" of diseases. However, thin people have relatively weak resistance and poor adaptability to the environment, especially acute infectious diseases such as influenza, upper respiratory tract infection and pneumonia, so they are sick and short-lived.

References:

Baidu encyclopedia-standard weight