Normal weight is often calculated in conjunction with height, i.e. Body Mass Index BMI. BMI = weight (kg) / height (cm) squared. According to the body mass index to determine whether the weight belongs to the normal range, reflecting the main systemic obesity and overweight. Calculation: BMI = weight (kg) / height (cm). For children, there is another formula, (7~16 years old) standard weight (kg) = age*2+8. The optimal range of BMI for Chinese people is 18.5~23.9, if BMI≥24 is overweight, and ≥28 is called obesity, which is easy to lead to the emergence of cardiovascular related diseases, it is recommended to consult a doctor to manage weight, control diet while strengthening exercise to measure the management of body mass index.