Body mass index is usually divided into domestic standards and world standards, China’s body mass index standards are body mass index between 18.5-23.9 for normal values, body mass index between 24-27.9 for overweight, body mass index ≥ 28 for obese. The world standard body mass index between 18.5-24.9 is the normal value, body mass index between 25-29.9 is overweight, body mass index ≥ 30 is obese. The calculation of body mass index is the body weight (kg) / height squared (square meters), it is an important indicator to determine whether a person’s figure is obese.