BMI30kg/m2 belongs to several levels need to be combined with the presence of complications, if there are no complications, it is 0 obesity, the specific grade is recommended to consult a doctor. Body Mass Index (BMI) is a standard used internationally to measure the degree of fatness and thinness of the human body and whether it is healthy or not, and is calculated by dividing the weight (kg) by the square of the height (m).The BMI of 18.5~23.9 is normal, the BMI of 24~27.9 is overweight, the BMI is equal to or greater than 28 is overweight, and the BMI is equal to or greater than 30 is obesity. Normal weight was BMI <25kg/m2 or <23kg/m2 (certain races) with waist circumference below the obesity cutoff; overweight grade 0 was BMI 25.0 to 29.9kg/m2 or 23.0 to 24.9kg/m2 (certain races) without complications; obesity grade 0 was BMI ≥30Kg/m2 or ≥25kg/m2 (certain races) without complications; Obesity 1 is defined as BMI ≥25kg/m2 or ≥23kg/m2 (certain races) or with one or more mild to moderate complications; Obesity 2 is defined as BMI ≥25kg/m2 or ≥23kg/m2 (certain races) or with one or more severe complications. People with obesity are recommended to keep their weight within a reasonable range, exercise appropriately, limit total calorie intake, and reduce fat intake. Patients who are severely obese and unable to reduce their weight through exercise and dietary control are recommended to go to the hospital and under the guidance of the doctor to reduce their weight appropriately.