Over the past two decades, China has been undergoing rapid socio-economic and nutrition transitions. Along with these transitions, childhood obesity and its related metabolic and psychological abnormalities are becoming serious public health problems in China. However, no national figures on the occurrence of childhood obesity, its determinants and its relationship with metabolic syndrome were available in China, until now. Data of 44880 youngsters aged 7-17 years from the nationally representative 2002 China National Nutrition and Health survey was used to study the prevalence of childhood obesity. This thesis indicates that, the overweight prevalence of Chinese youngsters was 4.4% and the obesity prevalence was 0.9%, as defined by International Obesity Task Force criteria. The estimated total number of overweight youngsters was 12 million, which means that one in thirteen overweight children worldwide was living in China. Both the overweight and obesity prevalence and their increment were higher in urban than in rural areas and higher in boys than in girls. The prevalence increased with the family’s income level and the mother’s educational level. Compared with children with normal weight parents, the prevalence increased if one or both parent(s) were overweight or obese, up to more than 10 fold (Prevalence ratio 12.2, 95% CI: 7.2-20.7) in case both parents were obese. Compared to their normal weight counterparts, overweight children consumed significantly more dietary energy (4.8%), protein and fat, but less carbohydrate; more cooking oil, meat and meat products, and dairy products, but less cereal grains and vegetables. On average, overweight children spent half an hour less on moderate/vigorous activities, and 2.3 hours more on low intensity (sedentary) activities per week. The prevalence ratio (0.6) of children who walked to and from school was statistically significant, indicated that children who walked to/from school have a 60% lower prevalence of overweight and obesity compared to those who went to/from school by bus. Other significant prevalence ratios were: moderate/vigorous activities ³ 45 min/day (0.8); low intensity physical activities >2 hours/day (1.3); consumption of ³ 25 g/d cooking oil (1.4); ³200 g/d meat and meat products (1.5); ³100 g/d dairy products (1.8). Overweight and obese children had higher risk of metabolic syndrome, body dissatisfaction and depression. It is estimated that more than 3 million Chinese adolescents aged 15 to 19 years have the metabolic syndrome (3.7%). Of the adolescents having parents with metabolic syndrome, once they are overweight or at risk of overweight, their risk of metabolic syndrome would be much higher (46.4%). Overweight girls, but not boys, had mildly but significantly higher total Children Depression Inventory score; both obese girls and obese boys showed a higher level of negative self-esteem scores, which was partially explained by body dissatisfaction. About seven in ten children were not satisfied with their body weight. More than one fifth underweight girls still wanted to be thinner while more than one third obese boys wanted to be heavier. Children who wanted to be thinner showed significantly higher scores of ineffectiveness and negative self-esteem. In conclusion, obesity is an increasing problem among youngsters in China, especially in urban areas. Since childhood obesity prevalence is positively associated with socio-economic status, the rapid economic development in China may result in a sharp rise in overweight and obesity prevalence unless effective preventive actions are taken. Fat intake, low intensity activities and active transport to/from school may be suitable targets for overweight prevention among Chinese school children.
|Qualification||Doctor of Philosophy|
|Award date||17 Dec 2007|
|Place of Publication||[S.l.]|
|Publication status||Published - 2007|
- disease prevalence
- metabolic disorders
- risk factors