Report on childhood obesity in China (8): effects and sustainability of physical activity intervention on body composition of Chinese youth / 生物医学与环境科学（英文）

<p><b>OBJECTIVES</b>To determine whether a large-scale physical activity intervention could affect body composition in primary school students in Beijing, China.</p><p><b>METHODS</b>The study design was one-year cluster randomized controlled trial of physical activity intervention (20 min of daily exercise in the classroom) with an additional year of follow-up among 4 700 students aged 8-11 years at baseline.</p><p><b>RESULTS</b>After the one-year intervention, BMI increased by 0.56 kg/m(2) (SD 1.15) in the intervention group and by 0.72 kg/m(2) (SD 1.20) in the control group, with a mean difference of -0.15 kg/m(2) (95% CI: -0.28 to -0.02). BMI z score decreased by -0.05 (SD 0.44) in the intervention group, but increased by 0.01 (SD 0.46) in the control group, with a mean difference of -0.07 (-0.13 to -0.01). After another year of follow up, compared to the control group, children in the intervention group had significantly lower BMI (-0.13, -0.25 to -0.01), BMI z score (-0.05, -0.10 to -0.01), fat mass (-0.27 kg, -0.53 to -0.02) and percent body fat (-0.53, -1.00 to -0.05). The intervention had a more pronounced effect on weight, height, BMI, BMI z score, and body composition among obese children than among normal weight or overweight children. Compared to the control group, the intervention group had a significantly higher percentage of children who maintained or reduced their BMI z score at year 1 (P=0.008) and year 2 (P=0.04).</p><p><b>CONCLUSIONS</b>These findings suggest that 20 min of daily moderate to vigorous physical activity during the school year is a feasible and effective way to prevent excessive gain of body weight, BMI, and body fatness in primary school students.</p>

Report on childhood obesity in China (5) body weight, body dissatisfaction, and depression symptoms of Chinese children aged 9-10 years / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the relationship between body weight, body dissatisfaction and depression symptoms among Chinese children.</p><p><b>METHODS</b>The fasting body weight and height of the third and fourth grade students (n = 3886, aged 9 or 10 years) from 20 schools in Beijing, China, were measured, and the students were asked to choose the figures of body image and to complete the self-reported children's depression inventory (CDI) questionnaire.</p><p><b>RESULTS</b>The CDI Cronbach's alpha was 0.81. The total CDI score was 9.60 +/- 7.50, 13.2% of children (boys 16.7% vs girls 9.5%) were at risk of developing depression symptoms. Overweight girls, but not boys, had significantly higher total CDI score than their normal weight counteparts. Both obese girls and boys showed a higher negative self-esteem score. More than one fifth underweight girls still wanted to be thinner while more than one third obese boys still wanted to be heavier. Children who wanted to be thinner showed slightly higher scores of ineffectiveness and negative self-esteem. After introducing the body dissatisfaction into the model, overweight was still associated with total CDI score among girls and obesity was still associated with negative self-esteem among both boys and girls.</p><p><b>CONCLUSION</b>Overweight girls show a significantly higher depression symptom score than their normal weight counterparts, which maybe partially explained by body dissatisfaction. Obese boys and girls are both more likely to suffer from low self-esteem, which is partially explained by body dissatisfaction.</p>

Report on childhood obesity in China (6) evaluation of a classroom-based physical activity promotion program / 生物医学与环境科学（英文）

<p><b>OBJECTIVES</b>To evaluate the effect of Happy 10 program on the promotion of physical activity, physical growth and development of primary-school students, and on obesity control and prevention.</p><p><b>METHODS</b>Two similar primary schools from one district of Beijing, China were selected, one as an intervention school and the other as a control school. Happy 10 program was implemented at least once every school day in the intervention school for two semesters, whereas no intervention was adopted in the control school. The information on energy expenditure and duration of physical activity was collected by a validated 7-day physical activity questionnaire. Height and weight were measured by trained investigators following the standardized procedure. Energy expenditure and intensity of each Happy 10 session was measured by a physical activity monitor.</p><p><b>RESULTS</b>The average energy expenditure and duration of total physical activity per day among students in the intervention school increased significantly from 15.0 to 18.2 kcal/kg, and 2.8 to 3.3 h respectively, whereas the figures significantly decreased in the control school. There was a significant difference in change of weight and BMI between girls in the intervention and control school (2.4 kg vs 4.6 kg, -0.47 kg/m2 vs 0.66 kg/m2). The prevalence of overweight and obesity in the intervention school decreased by 0.4%-5.6%, as compared to the increase by 0.6%-4.5% in the control school. The average energy expenditure and intensity per 10-minute session ranged from 25.0-35.1 kcal, 4.8-6.2 kcal/kg/h respectively in grades 1-5.</p><p><b>CONCLUSION</b>Happy 10 program provides a useful strategy to promote physical activity among school children and also plays a positive role in building up physical growth and development of girls.</p>

Study on the relation between anthropometric parameters and lipids profiles / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the relations between anthropometric parameters [body mass index (BMI), percent of body fat, waist circumference] and blood lipids of urban children in Beijing and to compare the ability of prediction effect of waist circumference, percent body fat and BMI on lipid profiles.</p><p><b>METHODS</b>852 children aged 9-10 were recruited with multi-stage sampling. Serum lipids of children were measured using automatic biochemical instrument. Fisher's exact test, trend test and median regression were used to analyze the data from 847 subjects with valid information.</p><p><b>RESULTS</b>(1)With the rise of the BMI, percent body fat and waist circumference, total triglycerides (TG), total cholesterol (TC) and low density lipoprotein choleasterol (LDL-C) showed increasing trends while high density lipoprotein choleasterol (HDL-C) had a decreasing trend(P < 0.01). (2)TG was mainly influenced by waist circumference (t = 6.86), sex (t = 3.96) and percent of body fat (t = 1.85); TC was influenced by percent of body fat (t = 5.31); LDL-C was influenced by waist circumference (t = 4.65), height (t = -2.79) and percent age of body fat (t = 2.77); HDL-C was influenced by waist circumference (t = -12.24), sex (1= -5.83).</p><p><b>CONCLUSION</b>With the aggravation of children's fatness (BMI, WC and PBF), serum lipids would increase and WC seemed to be the best predictor for lipids among BMI, WC and PBF.</p>

Report on childhood obesity in China (2). Verification of BMI classification reference for overweight and obesity in Chinese children and adolescents / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To verify Working Group for Obesity in China (WGOC) recommended body mass index (BMI) classification reference for overweight and obesity in Chinese children and adolescents using the data of 2002 China Nationwide Nutrition and Health Survey.</p><p><b>METHODS</b>Pediatric metabolic syndrome (MetS) and abnormality of each risk factor for MetS were defined using the criteria for US adolescents. Definition of hyper-TC, LDL, and dyslipidemia in adults was applied as well. The average level and abnormality rate of the metabolic indicators were described by BMI percentiles and compared with general linear model analysis. Receiver operating characteristic analysis was used to summarize the potential of BMI to discriminate between the presence and absence of the abnormality of these indicators.</p><p><b>RESULTS</b>There was neither significantly increasing nor significantly decreasing trend of biochemical parameter levels in low BMI percentile range (<65th). Slight increasing trend from the 75th and a significant increase were found when BMI > or =85th percentile. In general, the prevalence of the examined risk factors varied slightly when BMI percentile<75th, and substantial increases were consistently seen when BMI percentile > or =75th. As an indicator of hyper-TG, hypertension and MetS, the sensitivity and specificity were equal at the point of BMI<75th percentile, and the Youden's index of risk factors also reached peak point before 75th percentile except for MetS. When the BMI percentile was used as the screening indicator of MetS, Youden's index reached peak point at 85th percentile, just the point in the ROC graph that was nearest to the upper left corner.</p><p><b>CONCLUSION</b>The BMI classification reference for overweight and obesity recommended by WGOC is rational to predict and prevent health risks in Chinese children and adolescents. Lower screening cut-off points, such as 83th percentile or 80th percentile, should not be excluded when they are considered as overweight criteria in future intervention or prevention studies.</p>

Study on the current status and trend of food consumption among Chinese population / 中华流行病学杂志

<p><b>OBJECTIVE</b>To describe the current status and trend of food consumption among Chinese residents.</p><p><b>METHODS</b>23,470 households including 68,962 subjects were randomly sampled from 132 counties in 31 provinces, autonomous regions and municipalities. A 24-hour dietary recall method for 3 consecutive days was used to collect information on food intake, but the condiment intake was collected by weighting method.</p><p><b>RESULTS</b>The average food consumption per reference man per day of Chinese people included 402 g (urban/rural: 366 g/ 416 g) cereals; 276 g (urban/rural: 252 g/ 286 g) vegetables; 45 g (urban/rural:69 g/36 g) fruits; 79 g (urban/rural: 105 g/69 g) meats; 30 g (urban/rural:45 g/24 g) fishery products; 24 g (urban/rural: 33 g/20 g) eggs; 27 g(urban/rural: 66 g/ 11 g) dairy; 16 g legume; 42 g (urban/rural:44 g/41 g) edible oil; 12 g (urban/rural: 11 g/12 g) salt; 9 g (urban/rural: 11 g/8 g) soy sauce.</p><p><b>CONCLUSIONS</b>For Chinese residents, the quality of diet had been improved and consumptions of animal products, milk, and edible oil had been increased, but the consumptions of dairy and legume products intake was still low which called for improvement. The unbalance was characterized as the downward trend in cereal, vegetable and fruit consumption but significant increased in animal products and oil intake among urban people. Dietary pattern of some subjects adopted a "high energy density" diet. Double burdens from under-nutrition and over-nutrition should both be considered as problems which asked for attention by the government and researchers.</p>

Study on weight and height of the Chinese people and the differences between 1992 and 2002 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To describe the current situation and trends of mean weight and height of the Chinese people.</p><p><b>METHODS</b>Subjects of 71,971 households from 31 provinces were selected by stratified multi-stage cluster random sampling method. Height from 210 136 and weight from 202 749 subjects aged 2-79 years were used to describe their trends of development during 1992-2002. The height of children younger than 3 years of age was measured by infant height bed while the others were measured by metal height pole within 0.1 cm accuracy. Fasting body weight was measured to the nearest 0.1 kg.</p><p><b>RESULTS</b>Data on the mean height (cm) of Chinese children aged 2, 6, 11, 17 years were gathered which include: 1) in urban area: boys as 90.1 (2y), 118.4 (6y), 144.9 (11y), 170.2 (17y); girls as: 89.0 (2y), 117.0 (6y), 145.8 (11y), 158.6 (17y); 2) in rural area:boys as 87.6 (2y), 113.1 (6y), 139.2 (11y), 166.3 (17y) while girls as 86.2 (2y), 112.9 (6y), 140.0 (11y), 157.0 (17y). When compared to the results from 1992, the average height increased among all age groups. The values of increase among different groups aged 2-5 years were seen as: 3.6 cm of boys in urban and 3.0 cm of boys in rural areas while 3.8 cm of girls in urban and 3.0 cm of girls in rural areas. Among the aged 6-19 year groups, the average increasing values of height were 3.1 cm, 3.4 cm, 2.8 cm and 3.1 cm of city boys, rural boys, city girls and rural girls, respectively versus adults as 0.7 cm, 0.9 cm, 0.6 cm and 1.0 cm, respectively. The mean weight (kg) of Chinese children aged 2, 6, 11, 17 years were listed as below: boys in urban area: 13.5 (2y), 22.2 (6y), 37.4 (11y), 58.7 (17y); girls in urban area: 12.7 (2y), 21.2 (6y), 36.7 (11y), 51.9 (17y); boys in rural area: 12.8 (2y), 19.4 (6y), 31.9 (11y), 54.9 (17y); girls in rural area: 11.9 (2y), 18.7 (6y), 31.8 (11y), 51.2 (17y). The average weights of all age groups on 2002 were all higher than their same age counterparts in 1992. The average increasing values of weight among children aged 2-5 years were 1.0 kg, 0.6 kg, 0.8 kg and 0.5 kg for city boys, rural boys, city girls and rural girls, respectively. Among the aged 6-19 year groups, they were 2.0 kg, 1.5 kg, 1.4 kg and 1.1 kg, while among the adults aged 20-70 years, they were 3.2 kg, 3.0 kg, 1.6 kg and 2.9 kg, respectively.</p><p><b>CONCLUSION</b>Both mean weight and height had a remarkable increase and the physical status improved among all age groups for the last ten years.</p>

The prevalence of body overweight and obesity and its changes among Chinese people during 1992 to 2002 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To describe the prevalence of body overweight and obesity and its changes among Chinese people during 1992-2002, and to provide scientific basis for developing intervention strategies for obesity in China.</p><p><b>METHODS</b>The data from "1992 China third National Nutrition Survey" (78,704 subjects, 38,323 male and 40,381 female) and from "2002 China National Nutrition and Health Survey" (209,849 subjects, 101,377 male and 108,472 female) were used in this study. The overweight and obesity were defined by using WHO Z-score criteria for children younger than 7 years old, Chinese age-, sex-specific BMI criteria for children aged 7-17 years, and Chinese BMI criteria for adults.</p><p><b>RESULTS</b>The overall prevalence of overweight and obesity of Chinese people was increased by 38.6% and 80.6%, respectively during the period of 1992-2002. The prevalence of overweight and obesity of Chinese people aged 0-6 years, 7-17 years, 18-44 years, 45-59 years and above 60 years was increased 31.7%, 17.9%, 66.7%, 45.2% and 43.7%, respectively. The increase of the prevalence of overweight and obesity was higher in girls younger than 6 years than their male counterparts, while among other age groups, that were higher in boys than girls. The prevalence of overweight and obesity among people living in rural areas was lower than that of their urban counterparts, while the increment of overweight and obesity prevalence among rural people was greater than that of their urban counterparts. It was estimated that another 70 million overweight and 30 million obese Chinese people emerged in China from 1992 to 2002.</p><p><b>CONCLUSION</b>The prevalence of overweight and obesity of Chinese people was increased rapidly in the past decade, which had affected 260 million Chinese people. It would continue to increase in the near future if effective intervention measures have not been taken.</p>

The current prevalence status of body overweight and obesity in China: data from the China National Nutrition and Health Survey / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study on the prevalence of body overweight and obesity in China and its distribution in age, sex and economic development status.</p><p><b>METHODS</b>A total of 209,849 in all ages from the 2002 China National Nutrition and Health Survey (NNAHS) database were analyzed. The year 2000 population census data was used for age standardization. 1978 WHO criteria using Z scores was applied to age 0-7 years, criteria recommended by the Working Group on Obesity in China was applied to those aged 7-17 years and criteria in the Guidelines for Prevention and Control of Overweight and Obesity in Chinese Adults was applied to those aged 18 years and above.</p><p><b>RESULTS</b>The overall prevalence was 17.6% for overweight and 5.6% for obesity. The combined prevalence of overweight and obesity was 23.2%. The prevalence of overweight was 25.0%, 21.6%, 17.4%, 15.1%, 19.2% and 12.8%, respectively for large city, middle-and-small city, class 1 rural, class 2 rural, class 3 rural and class 4 rural. For obesity, the rate was 10.6%, 7.2%, 6.4%, 4.3%, 6.0% and 2.7%, respectively for large city, middle-and-small city, class 1 rural, class 2 rural, class 3 rural and class 4 rural. By age groups, the prevalence of overweight was 3.4% in children age 0-6, 4.5% in adolescents age 7-17, 22.8% in adults age 18 and above; the prevalence of obesity was 2.0% in children age 0-6, 2.7% in adolescents age 7-17, 7.1% in adults age 18 and above. The sex difference in overweight and obesity differed between urban and rural, and among age groups.</p><p><b>CONCLUSION</b>Overweight and obesity should have affected nearly 1 quarter of the country's total population, and became a threatening hazard to resident's health. As the urbanization progress, obesity might doubly increase. Prevention and control of this hazard should be urgently needed.</p>