Obesity refers to excessive accumulation and/or abnormal distribution of body fat and weight gain, and is the result of a combination of genetic and environmental factors. Obesity not only affects the aesthetic appearance of the human body, but also is an important risk factor for many chronic diseases, such as diabetes, cardiovascular and other diseases, which has seriously affected people’s quality of life and shortened the life expectancy of patients. Childhood obesity not only affects children’s physical and mental development and intellectual development, but also affects the child’s sexual development and height. The indicators for judging obesity usually use body mass index and waist/hip ratio. Chinese people’s body mass index is normal when it is 18.5-23.9, ≥24 is overweight, and ≥28 is obese. Abdominal obesity with a waist/hip ratio greater than 1.0 for men and 0.85 for women is as harmful as a high BMI. Clinically, obesity is often divided into simple obesity and pathologic obesity, the latter is common in many endocrine system diseases such as: diabetes mellitus, polycystic ovary syndrome, Kirchhoff’s syndrome, hypothyroidism and so on. Therefore, for obese patients need to carry out a series of examinations, for the cause of treatment, and should not blindly lose weight.