Whether the adult's weight is appropriate can be expressed by the internationally accepted body mass index (body mass index). Body mass index is obtained by dividing weight (kg) by the square of height (m), which reflects the relationship between a person's height and weight.
The healthy weight of adults in China ranges from body mass index = 18.5 kg/m2 to 23.9 kg/m2.
If the body mass index is less than 18.5 kg/m2, it is emaciation; If it is between 24 kg/m2 and 27.9 kg/m2, it is overweight; If it is equal to or greater than 28 kg/m2, it is obesity.
For most adults, the body mass index can reflect the body fat content to some extent, and most of the weight gain is the increase of fat. But it is not suitable for people with particularly developed muscles such as athletes.