Body mass index (BMI) is a number obtained by dividing the weight in kilograms by the square of the height in meters, the unit is kg/m^2, which is an international standard commonly used to measure the degree of fatness and thinness of the human body and whether it is healthy or not, the normal range is 18.5-24.0kg/m^2. 32.0kg/m^2 is considered very obese. Better indicators to measure whether a patient is obese or not are currently body fat percentage, waist circumference to height ratio, and visceral fat measurement. Of these, visceral fat measurement is the best measure of weight for obesity.