A definition of obesity : obesity (obesity) is a long-term energy intake exceeds consumption , resulting in excess body store energy in the form of fat , fat accumulation reached the extent of damage to health . Obesity and overweight is not the same , body fat is the fat tissue increased, and excess is the increase in weight relative to height or exceed certain standards and reference values. Obesity is a multifactorial disease , and affects the health of individuals , resulting in many adverse social consequences. 95% of children are obese , childhood obesity is a simple exclude congenital genetic diseases and metabolic disorders and neurological and endocrine diseases caused by sexually transmitted diseases secondary to obesity rational , but simply acts by some factors of life caused by obesity. Human obesity, is highly developed material civilization of modern society , the emergence of the " diseases of civilization ." Obesity is caused by excessive accumulation of body fat, the phenomenon is not seen as a "healthy" sign. Obesity not only affects the physical beauty, but also to the inconvenience of life , but more importantly it is easy to cause a variety of complications , accelerated aging and death. No wonder people say obesity is a sign of the disease , the aging of the signal. -

2, the current social Obesity : Childhood obesity has become a growing public health problem of global attention . Childhood obesity in both developed and developing countries were tested rapidly rising trend. According to the WHO report , the global rate of nearly 10 percent of children are overweight , obesity rate of 2 % -3% ; American and European countries children are overweight rate of 20% -30% , obesity rate of 5 % -15%. Nearly 15 years, low socioeconomic status of the population of children and adolescents overall prevalence of overweight and obesity increased from 10.4% up to 29.3% , an increase of 2 times, and higher socioeconomic status of the population of overweight and obesity increased from 13.0 to grow to 21.7% less than 1 -fold increase . - Of childhood obesity rates are increasing year by year . South of the fastest growing , with data reported in some areas over the past 15 years, the boy grew 9.6 times obesity rate for girls increased by 4.9 times . Rates of childhood obesity presents urban than in rural areas, socio-economic status of the population has a higher rate of obesity , which contrast with the developed countries . 2000 National 7-22 year-old urban male obesity was 5.72% , 2.94% for females ; rural areas respectively 1.90% and 1.15% , between urban and rural areas there is a significant difference. -

3 , the dangers of obesity : Obesity not only makes people bloated , overburdened , but also lead to hypertension , diabetes, atherosclerosis , cardiac ischemia, lower extremity joint disorders and other diseases , but also brings extremely adverse psychological effects . Therefore, in recent years, medical experts and scholars at home and abroad , studying and finding effective ways to lose weight . -
( 1 ) According to statistics, health and longevity of the enemy obese cerebral embolism and heart failure incidence rate twice as high as normal weight , the risk of coronary heart disease and more than 2 times the normal weight , incidence of hypertension than normal weight and more 2 to 6 times higher than normal with diabetes increased about four times higher than normal cholelithiasis by 4-6 times , more serious is obesity life will be significantly shortened. It is reported that 10% of overweight 45 -year-old man , whose life than normal weight should be shortened four years , according to Japanese statistics show that 100% of the standard percentage mortality , obesity mortality rate was 127.9% . -
( 2 ) prone to coronary heart disease and hypertension, obesity increase in adipose tissue , oxygen consumption increased cardiac work capacity, myocardial hypertrophy, left ventricular particular burden , a long time easily induced hypertension . Lipid deposition in the arterial wall , resulting in stenosis , hardening , prone to coronary heart disease, angina , stroke and sudden death. -
( 3 ) impact of labor and vulnerable to trauma obese people tend to heat intolerance , sweating , fatigue, lower extremity edema , varicose veins, skin folds suffering from dermatitis , severely obese people , slow, have difficulty walking activities , a little flustered shortness of breath activity , which affects normal life , serious and even lead to loss of labor . Because obesity slow response action , but also vulnerable to a variety of injuries , car accidents, fractures and sprains .
( 4 ) susceptible to endocrine and metabolic diseases associated with obesity caused by metabolic , endocrine abnormalities , often can cause a variety of diseases. Diabetes can cause abnormal glucose metabolism , fat metabolism can cause hyperlipidemia , nucleic acid metabolism can cause hyperuricemia . Obese women due to ovarian dysfunction can cause irregular menstruation. -
( 5 ) have an adverse effect on lung function is the role of pulmonary oxygen supply to the body and exhaling carbon dioxide . Obesity due to weight gain requires more oxygen, but not correspondingly increased lung function, while obesity and abdominal fat accumulation limits lung breathing exercise , it can cause hypoxia and breathing difficulties , leading to heart and lung failure . -
( 6 ) can lead to liver and gallbladder disease because obesity hyperinsulinemia it triglyceride synthesis of endogenous hyperthyroidism , will result in the synthesis of triglycerides in the liver to form the accumulation of fatty liver . Obese compared with normal cholesterol levels in bile acid increased , exceeding the solubility of bile , so easy to concurrent obesity high proportion of cholesterol gallstones, gallstones has been reported 50 to 80% of women are obese . In the surgery , about 30% of the height of the obesity associated with gallstones. Gallstone disease in the following situations more : obese women aged over 40 , those with normal weight obesity compared to women about their incidence of gallstones six times higher . -
( 7 ) will increase the difficulty of surgery , postoperative infection Obesity increases the risk of anesthesia , post-operative wound dehiscence easily infected hypostatic pneumonia and other complications of fat than those who do not as much . -
( 8 ) can cause weight gain arthropathy make many joints ( such as the spine, shoulder, elbow, hip and ankle joints ) wear and tear caused the pain. -

 4 Causes and risk factors -
( 1 ) genetic factors obesity gene plays an important role . Studies have shown that the distribution of body fat and up to 65% heritability -80 % , a considerable genetic and height . Currently more than 200 species have been discovered gene loci and the occurrence of obesity , many genes involved in the interaction with the environment is the reason most people obese . From the perspective of human evolution , including obesity , cardiovascular disease, diabetes , cancer and other diseases, a significant increase in the incidence of the reason lies in our inherent genetic profile and the environment we live in today does not fit our ancestors up to several hundred of years of evolution, its existence has always been experiencing lack of food , starvation , humans gradually formed a set against hunger response system ; opposite of human hunger is released , the body has not yet formed an effective mechanism to combat these changes , it led to the corresponding diseases ( such as obesity ) increased incidence . -
( 2 ) excessive energy intake and low physical activity people today getting adequate food , along with low physical activity and lifestyle changes are also external factors that lead to obesity increase . Watching TV and playing video games and obesity in children and adolescents have a strong correlation , watching TV is often accompanied by snacking behavior , increased energy intake , while reducing energy consumption. It was found a day watching television 1h, playing video games the risk of childhood obesity increased by 12% a day watching television more than 3h of childhood obesity rate of 31.2%. Also with the organic and inorganic chemical materials used , the human living environment has changed . Some chemicals ( such as certain pesticides , plant hormones , synthetic detergent , petroleum products, etc. ) in large doses can cause weight loss, but small doses can lead to weight gain. Toxic chemicals may be associated with an increasing incidence of obesity there is some connection , but its mechanisms still need to be further confirmed. -
( 3 ) low birth weight and high birth weight children with low birth weight due to intrauterine fetal environment leads to malnutrition , in order to ensure the growth of vital organs such as the brain and internal organs to reduce the supply of nutrients . Organs adapted metabolic state at a low level so that the internal organs is a potential exception. When nutrition after birth in an environment of relative surplus occurs when catch-up growth leaving the function of internal organs imbalance , metabolic disorders, obesity, type 2 diabetes is characterized by insulin resistance and metabolic diseases. High birth weight is childhood obesity is an important risk factor. 2001 on Beijing 's ten thousand obese children aged 6-8 survey found that with the increase in birth weight , increased obesity rates skyrocketed after meet or exceed 4000g , 1 /3 of children are overweight and obese , from see the degree of obesity , low birth weight children with mild obesity based, and high birth weight places severe majority.