With the development of our society and economy and the improvement of people’s living standards, the prevalence of obesity in China has been on the rise in recent years. Obesity is becoming more and more common around us. For different degrees of fat gain, many people began to lose weight disorders, then exactly is obesity a disease? This article will be combined with the Chinese adult overweight and obesity prevention and control guidelines on this issue to do a detailed interpretation. A, understanding obesity obesity is a multi-factor-induced chronic metabolic diseases, as early as 1948 the World Health Organization has included it in the list of disease classification. Overweight and obesity can cause a series of health, social and psychological problems. There has been evidence that overweight and obesity is an important risk factor for cardiovascular disease, diabetes, certain cancers and some other chronic diseases; at the same time, there are some countries with obesity patients, because of discrimination at work and unsatisfied with their own body shape and low self-esteem, resulting in high suicide rate, low marriage rate and other social problems. Second, the characteristics of obesity patients The general characteristics of obesity patients for the body fat cell volume and cell number increase, body fat percentage of body weight (body fat %) is abnormally high, and in some local excessive deposition of fat. If the fat accumulation mainly in the abdominal wall and abdominal cavity is excessive, known as “central” or “centripetal” obesity, then the metabolic impact is great. Centripetal obesity is one of the most important risk factors for many chronic diseases. Obesity without endocrine disease or cannot find the specific cause of obesity is simple obesity. Simple obesity accounts for more than 95% of the total number of obese people. The observation of human appearance usually can roughly estimate the degree of obesity and wasting, applicable to the initial screening, but can not be quantitative. Third, the degree of classification of obesity to the classification of obesity degree of body mass index, the international usually use the World Health Organization (WHO) to develop the body mass index boundary value, that is, the body mass index in 25.0-29.9 for overweight, greater than or equal to 30 for obese. Recently, the working group on obesity in China of the International Life Sciences Society China Office has analyzed the relationship between body mass index and the prevalence of related diseases based on the large-scale measurement data of the population in China, and proposed the threshold value for judging the degree of overweight and obesity for Chinese adults, and the risk of related diseases by combining with waist circumference. The WHO obesity expert advisory group, in view of the characteristics of the population in the Asia-Pacific region and its diseases related to obesity, also proposed in 2002 the boundary value of the risk of disease development for Asian adults at different levels of body mass index and waist circumference, that is, the body mass index is 23.0-24.9 for pre-obesity and more than 25 for obesity, and suggested that each country should collect epidemiological and disease risk data of obesity of its residents to determine the body mass index of its population. classification criteria. It is noteworthy that people whose body mass index is over the limit in their youth may have a higher risk of developing related diseases later than those who become obese after middle and old age.