Objective To study the prevalence,characteristics and related factors of weight control behavior among middle school students in Xicheng district of Beijing and to provide scientific basis for developing policy and effective intervention.Methods A total of 1 930 students were selected from 9 middle schools in Xicheng district of Beijing for a self-administered questionnaire survey.Results Among the students,32.3% had history of weight control.The report rate of dieting,fasting,vomiting or diarrhea,and taking slimming drugs was 31.9%,3.8%,1.4%,and 2.7%.The risk of taking weight-reducing measures of the girls was 2.444 times higher than that of boys and the risk of weight control behavior for high middle school students was 1.313 times higher than that of junior school students and the occupational high school students had a 1.465 times higher risk than junior school students.Conclusion Some teenagers have unscientific weight loss behaviors.Gender and school grade are influential factors of unhealthy diet behavior.It is necessary to guide young people to understand the meaning of health correctly,and to master the skills to determine the body weight according to characteristics of the students.

OBJECTIVE:To compare the changes in body composition, including fat mass index (FMI) and fat free mass index (FFMI) during puberty development of obese and normal-weight children in China, and to explore the effect of age and gender on body composition. METHODS:A total of 356 children at the age of 7-15 years were enrolled in this study. Body composition of 10 normal-weight and obese children in each age group was measured by dual-energy x-ray absorptiometry (DEXA). FFMI and FMI were calculated according to the following formula: FFMI (kg x m(-2)) = FFM(kg) / height2 (m2) and FMI (kg x m(-2)) = FM (kg) / height2 (m2). RESULTS:The fat mass and fat free mass of obese children were significantly higher than those of normal-weight children (P < 0.05). The FMI and FFMI of obese children increased significantly with age and were higher than those of the same sex, gender, and age normal-weight children (P < 0.05). CONCLUSION:The levels of fat mass, fat free mass, FMI, and FFMI are different in obese and normal-weight children, and gender effects are significant in boys having higher levels of these indicators than in girls. FFMI and FMI can be used as monitoring indexes in weight control of obese children.

儿童青少年肥胖已成为全球性的公共卫生问题.国内外许多研究表明,儿童超重肥胖与许多成年期慢性病如高血压、高脂血症、糖尿病、动脉粥样硬化性心脑血管疾病关系密切;腰围及腰臀比(WHR)与内脏脂肪堆积密切相关,随着WHR增加,患者病死率及心血管疾病危险性也随之增加.

ObjectiveTo test the association of insulin induced gene 2(INSIG2) rs7566605 polymprphism with obesity and the metabolic abnormalities in children and adolescents in China.MethodsOrerall 1 103 students aged 7 to 18-year-old were sellected in Haidian district,Beijing.The body and metabolic indexes were measured and the rs7566605 polymorohism was genotyped.ResultsThe mutation rate of rs7566605(GC) in the children and adolescents was 35.56% to 37.06%,similar to those of European and the United States population.The differences of genotype and allele frequencies in normal weight,overweight and obese group were not significant(P0.05).Stratified analyses showed that the CC genotype carriers in overweight group had higher skinfold thickness and body fat percentage than that of GG/GC genotype(P0.05).Average level of triglyceride(TG) of CC genotype carriers was 0.21mmol/L and higher than that of GG/GC genotype in obese group(P=0.014).ConclusionThere was no association between INSIG2 gene rs7566605 polymorghism and childhood overweight or obesity in China.But the polymorphism may have some influence on TG accumulation and body fat content in overweight or obese children and adolescents in China.

Objective To explore the relationship between body mass index(BMI),waist circumference(WC) and blood pressure,and to provide evidence for the interventions of children' s obesity.Methods The normal-weight,overweight and obese children were selected from three middle schools and two primary schools in Beijing according to the results of height and weight in student' s physical examination 2005-2006.Height,weight,WC and blood pressure were measured for all the 1 082 volunteers aged 7-15 years old.Results The level and prevalence of higher blood pressure were obeseoverweightnormal-weight and higher WCnormal WC.There were significant differences in different nutritional status and different WC groups(P0.01).SBP and DBP were positively correlated with BMI and WC.Conclusion Regular check for children' s blood pressure is of great significance to prevent and control obese children' s hypertension.

Objective To explore the prevalence of metabolic syndrome(MS) and its compoments among overweight and obese children,and to provide evidence for prevention of obesity and MS.Methods Normal-weight,overweight and obese children were selected from three middle schools and two primary schools in Beijing,according to the results of height and weight in 2005-2006 students' physical examination.Height,weight,waist circumference(WC),blood pressure,TC,TG,HDL-C,LDL-C and FPG were measured for all the 1 042 volunteers aged 7-15 years old.Results Except for TC in female children,there were significant differences at the levels of components of MS among male and female children with different body type(P0.01).For the levels of SBP,DBP,WC,LDL-C,TG and FPG,obesity overweight normal-weight,while for HDL-C,obesity overweight normal-weight.Except for the prevalence of abnomal FPG in female children,there were significant differences of the prevalences of MS and its compoments among male and female children with different body types(P0.05),obesity overweight normal-weight.Conclusion Compared with normal-weight children,overweight and obese children have abnormal blood pressure,serum lipids and fasting glucose,examination of MS compoments should be strengthened to prevent obesity and reduce MS.

Objective To study the physical activity,sports' motivation and feeling of adolescents in Beijing Yayuncun community and surrounding areas,and to provide baseline data for improving adolescents' health by program related to "Healthy Olympic Games,Healthy Beijing".Methods From a Yayuncun community and surrounding areas in Beijing Chaoyang district,455 students in junior high school(grade 8) and senior high school(grade 11) were selected to answer "Beijing Typical Community Adolescent Questionnaire",through which the adolescents' physical activity,sports' motivation and feeling were investigated.Results It showed that the top participating percent was basketball playing(79.70%) in boys and walking(65.48%) in girls.Further analysis disclosed that boys had stronger intrinsic and extrinsic motivation and exercise-induced positive feeling than girls(P<0.01).Meanwhile,boys playing basketball had stronger intrinsic and extrinsic motivation and exercise-induced positive feeling than those not playing.More over,walking girls had stronger intrinsic and extrinsic motivation than those not walking(P<0.05).Conclusion Diverse sport activities and sport promoting environment are key factors to improve adolescents' physical fitness.

Objective To know the status of environmental and life among residents living in Yayuncun community in Beijing.Methods 1?641 permanent residents above 15 years old from 600 families inhabiting in the Yayuncun community since the year of 2000 were selected into the cohort in 2006 to answer Beijing Typical Community Resident Questionnaire designed by the researcher.The residents' basic information,environmental and life and other information were collected and 1?583 permanent residents were followed up in 2007.Meanwhile,333 and 410 temporary residents were investigated used the same questionnaire in 2006 and 2007,respectively.Results The rates of environmental and life were higher among permanent residents in 2007 than in 2006(P0.01).The top 3 aspects with the highet rates among permanent residents in 2006 were total life satisfaction,green space and family housing condition,the rate was 50.6%,48.4% and 39.1%,and in 2007 were green space,total life satisfaction and water quality,the rate was 64.0%,56.5% and 48.5%,respectively.The rates of environmental and life had no significant difference among temporary residents between 2006 and 2007(P0.05).Multivariable linear regression showed that medical insurance type,permanent resident or temporary resident,different year were independent factors of environmental and life satisfaction(P0.01).Conclusion All of the components of environmental and life degree were increased in 2007,and the environmental amelioration of community would impact the life of residents.

Objective To explore the prevalence of fatty liver among overweight and obese children,and to provide evidence for prevention of obesity and fatty liver.Methods Normal-weight,overweight and obese children were selected from three middle schools and two primary schools in Beijing,according to the results of height and weight in 2005-2006 students' physical examination.Height and weight,liver ultrasound B scans,serum lipids and ALT were examined for 1 011 volunteers aged 7-15 years old.Results The prevalence of fatty liver in overweight and obese children was obviously higher than that in normal-weight children.Except for TC,there were significant differences of the level of serum lipids between fatty liver and non-fatty liver children(P0.01).Conclusion Compared with normal-weight children,the prevalence of fatty liver in overweight and obese children is higher.Examination with liver ultrasound B scans should be strengthened to prevent the incidence of fatty liver.

Objective To study the association between the rs7566605 variant of INSIG2 and obesity-related phenotypes in Chinese children and adolescents. Methods The study sample consisted of two independent cohorts of Chinese children and adolescents. Anthropometric indices, lipids, blood pressure, fasting glucose, insulin and percentage of fat mass were determined. PCR with restriction fragment length polymorphism analysis was performed for genotyping the rs7566605 variant. Results In each of the two independent cohorts, no significant association was observed between rs7566605 and obesity under additive, dominant or recessive model. We also did not detect any difference in the genotype frequency between all the obese children and controls. Furthermore, we did not find evidence of an association between body composition indices and metabolic phenotypes in all children. However, the triglyceride level of CC homozygotes was significantly higher than that of GG+GC genotypes in obese children (P=0.022). Additionally, we observed a non-significant trend of severe obesity in a post-hoc test. Conclusion INSIG2 rs7566605 variant is not associated Chinese childhood obesity in two independent cohorts. Further study is needed to verify the effect of rs7566605 on triglyceride in obese children.

Objective To know the status of utilization of sport facilities in Yayuncun community in Beijing.Methods 1765 permanent residents above 15 years old from 600 families inhabiting in the Yayuncun community since the year of 2000 were selected into the cohort to answer Beijing Typical Community Resident Questionnaire designed by the researcher.The residents' health knowledge,health behavior,health status,physical activity and the usage of sport facilities were surveyed.And the cohort was followed-up through 2006 and 2007.Results The average area of sport facilities per person in Yayuncun community was 1.55 m2.The prevalence of often utilizing the sports facilities near the residence among residents in Yayuncun community was higher in 2007(24.1%) than in the baseline(18.1%) and 2006(22.3%)(χ2=6.407,P0.05).The sports facilities located in the communities were the first choices for residents.The prevalence of exercising with the communities' sport facilities among residents were higher in 2006(41.4%) and 2007(44.5%) than in the baseline(36.0%)(χ2=36.993,P0.01).The satisfaction degree focused on the quantity,quality,open time,charge standard and security of the sport facilities increased in 2007 compared with 2006 and the baseline.Logistic regression showed that educational level,accessibility of the sport facilities,satisfaction for the number and security of the sport facilities were independent factors for the utilization of the sport facilities(P0.01).Conclusion In order to meet the growing demand of physical exercises of the residents,the Yayuncun community should increase the categories and quantities,as well as strengthen the management of sport facilities.

Objective To study the daily physical activities of adolescents in Yayuncun Community and surrounding areas,and to provide baseline data for improving adolescents' health by Healthy Olympic Games,Healthy related activities.Methods From a Yayuncun Community and surrounding areas in Chaoyang district,456 students in junior high school(grade 8) and senior high school(grade 11) were selected to answer Beijing Typical Community adolescent Questionnaire,through which the adolescents' daily physical activities were obtained and analyzed.Results It was found that among the surveyed students the average length for outdoor activities was 51.94 mind,while for housework: Cooking was 0.19 hd,washing 0.56 hweek and sweeping 0.53 hd respectively.Whereas,students spent 2.38 h,1.26 h,1.05 h and 0.49 h respectively on doing homework,watching TV,playing computer or electric games respectively.Conclusion Targeted measures and intervention should be taken to increase physical activities and decrease sedentary action in adolescents.

世界卫生组织指出,目前世界上首位死因是慢性病,慢性病死亡的80%发生在低收入和中等收入国家[1].慢性病的发生与吸烟、饮酒、高脂饮食、肥胖及缺乏体育锻炼密切相关[2-3],本研究作为"奥运健康遗产"研究课题,观察慢性病患病及其与相关危险行为的关系,评估奥运会对举办地居民健康所产生的影响.

Objective To explore the characteristics of fasting glucose and serum lipids in overweight and obese children,and to provide evidence for the intervention against children's obesity. Methods The normal-weight,overweight and obese children were selected from three middle schools and two primary schools in Beijing according to the results of height and weight in students' physical examination in 2005-2006. Height,weight,TC,TG,HDL-C,LDL-C and FPG were measured for all the 1 045 students aged 7-15 years old. Results There were significant differences in the levels of FPG,TG,HDL-C and LDL-C between boys and girls with different body types(P<0.01). The level of HDL-C was obesity<overweight<normal weight,FPG,TG,LDL-C were obesity>overweight>normal weight. Except for TC,the prevalence of higher FPG,TG,LDL-C and lower HDL-C in male children was obesity>overweight>normal weight. There were no significant differences in abnormal prevalence of FPG,TC,LDL-C in female children(P>0.05),the prevalence of higher TG and lower HDL-C was obesity>overweight>normal-weight. Conclusion Compared with normal-weight children,overweight and obese children have abnormal fasting glucose and serum lipids,test of fasting glucose and serum lipids and comprehensive interventions for overweight and obese children should be strengthened.

Objectives To analyze the characteristics of body fat mass and fat-free mass in children and adolescents and their change with age and difference by gender.Methods Totally,180 healthy children and adolescents aged 7～15 years with normal body weight were selected for investigation,10 for each age-group in both boys and girls.Body fat mass and fat-free mass were measured by dual-energy x-ray absorptiometry(DEXA).Fat-free mass index(FFMI)and fat mass index(FMI)were calculated according to following equations:FFMI(kg·m~(-2))=FFM(kg)/height~2(m~2),and FMI(kg·m~(-2))=FM(kg)/height~2(m~2). Results Fat mass and body fat percentage increased with age in children from 7 to 13 years old and decreased after 13 years old. Girl's FM was higher than boy's.Both boy's and girl's FFMI increased with age between 7～15 years old and the increase of boy's FFMI accelerated during puberty,with a total increment of twice as girl's.At 7～15 years old,boy's FM!increased first and then decreased,while girl's increased all along during this phase.Total increment of girl's FMI was about twice as boy's.Body height poorly correlated with FM1 in boys,while it correlated with FFMI in boys at age of 11～15 years significantly(P0.05).Body height correlated with FM1 in girls at age of 7～10 years and with FFMI at age of 9～10 years significantly(P0.05).BMI correlated with FMI significantly both in boys and girls with a larger coefficient of correlation for boy's.BMI correlated significantly with FFMI for boys at 13-15 years old and girls aged 7～15 years,respectively(P0.05).Conclusions Fat mass and fat-free mass,as well as their distribution,changed with age in childrenaround their puberty.There was significant difference in fat mass and fat-free mass between boys and girls.Acceleration phase for concentric distribution of fat mass was at age of 12 years in boys and 10 in girls.Boy's BMI increment with age mainly came from their FFM,especially in adolescent boys.While increment of BMi Jn girls attributed to both FFM and FM.

Objective To analyze changes of FFMI and FMI with age and gender differentiation of normal-weight children during puberty development,and to provide bases for the prevention and control of obesity.Methods For each gender and age group from 7 to 15 years old,about 10 normal-weight children(180 subjects totally) were selected to receive body composition measurement by dual-energy X-ray absorptiometry(DEXA).FFMI and FMI were calculated according to following expressions: FFMI(kg·m~(-2))=FFM(kg)/height(m)~2 and FMI(kg·m~(-2))=FM(kg)/height(m)~2.Results Both boy's and girl's FFMI increased with age between 7-15 years old and the increase of boy's FFMI accelerated since adolescence began.The total increment was about twice of girl's.Boy's FMI increased first and then decreased while girl's FMI increased all along from 7 to 15 years old.The total increment of girl's FMI was about twice of boy's.Boy's height correlated with FMI slightly while with FFMI of 11-5 years old significantly(P0.05).Girl's height positively correlated with FFMI at 7-10 years old and FMI at 9-10 years old significantly(P0.05).Both boy's and girl's BMI correlated with FMI significantly and the coefficient in boys was larger than in girls.BMI correlated significantly and positively with FFMI for boys aged 13-15 and girls aged 7-15(P(0.05).) Conclusion The increment of boy's BMI with age mainly comes from increment of FFMI,especially among boys in adolescence,while the increment of girl's BMI attribute to the increments of both FFMI and FMI.

Objective To compare body composition,characters of its changes with age of normal-weight children aged 7-15 years,and to provide evidence for the impact evaluation on children's weight control.Methods A total of 356 children were chosen,and for each sexual and age group from 7-15 years old,about 10 normal-weight children were selected to receive body composition measurement by dual-energy X-ray absorption(DEXA).Results Both fat mass and fat free mass of obese children were significantly higher than those of normal-weight children(P0.05).When compared with normal-weight children,differences of fat and muscle distributions between limbs and trunk were smaller in obese children.The ratio of android and gynoid fat percents(A/G ratio) were significantly higher than that of normal-weight children.A/G ratio of obese boys was increased with age and exceeded 1 except 8 years group while the girls' was stable comparatively anf less than 1 except 9 and 13 years group.Conclusion Differences exist in the respects of quality,ratio and distribution of fat mass and fat free mass between obese and normal-weight children and sexual differentiation was significant. Characters and changes of body composition should be considered during the weight control of obese children.

Objective To make a comparison on fat-free mass index(FFMI) and fat mass index(FMI),their changes with growth and sexual differentiation between obese and normal-weight children during puberty development,and to provide information for obese children's weight control and the impact evaluation.Methods For each gender and age group from 7 to 15 years old,about 10 normal-weight children(356 totally) were selected to receive body composition measurement by dual-energy X-ray absorptionmetry(DEXA).FFMI and FMI were calculated.Results Both FFMI and FMI of obese children aged 7-15 years old increased with age which were higher than those of normal-weight children significantly for each group(P0.05).FMI correlated with BMI positively and significantly for obese children aged 7-15 years old with a higher correlative coefficient than that of normal-weight children.FFMI correlated with BMI positively and significantly for obese children(P0.05) and the correlative coefficient for boy tended to increasing with age.The correlation between FMI and FFMI was statistically significant for obese boys and girls aged 13-15 years(P0.05).Conclusion Compared with normal-weight children,obese children have higher FFMI,FMI,BMI and body fat percentage.In the same range of body fat percentage,BMI of obese children is different for different age group because of different FFMI and FMI.FFMI and FMI are valuable surveillance indices for weight management in obese children.

目的比较青春发育期体重正常和肥胖儿童青少年非脂肪组织指数（FFMI）和脂肪组织指数（FMI）及其随年龄变化趋势和性别差异,为肥胖儿童体重控制及其效果评价提供基础数据。方法选择北京市715岁体重正常和肥胖儿童356名,不同性别各年龄组约10人,采用双能X线吸收法（DEXA）测定身体成分,计算FFMI和FMI。结果715岁肥胖儿童FFMI和FMI均随年龄增长而增加,且高于同性别、同年龄组体重正常儿童,差异均有统计学意义（P值均<0.05）。715岁肥胖儿童FMI与BMI呈高度正相关（P<0.05）,相关系数大于体重正常儿童;肥胖儿童FFMI与BMI呈中度正相关（P<0.05）,肥胖男生相关系数随年龄增长有上升趋势。78岁肥胖女生FMI和FFMI与身高相关性均有统计学意义（P值均<0.05）。1315岁肥胖儿童FMI和FFMI呈正相关关系,且差异有统计学意义（P<0.05）。结论肥胖儿童与体重正常儿童相比,有FFMI高、FMI高、BMI高和脂肪百分比高的特点。在同一脂肪百分比范围内,不同年龄的FFMI和FMI交点可跨越多个BMI。FFMI和FMI是肥胖儿童的体重研究中值得应用的监测指标。

Objective To analyze body composition, characters of its changes with age and sexual difference of normal-weight children aged 7-15 years, and to provide evidence for children's growth and development. Methods From a primary and a secondary schools,For each sexual and age group of 7-15 years old, about 10 normal-weight children (180 subjects totally) were selected to receive body composition measurement by dual-energy x-ray absorption(DEXA). Results Fat mass and body fat percentage increased with age from 7 to 13 years old and decreased after 13 years old. Girl's were higher than boy's. Fat-free mass increased with age. Percentages of limb and trunk fat accounting for body fat approached to each other with age. Percentages of limb fat accounting for body fat was higher than that of trunk fat for boys aged 7-13 years and girls aged 7-12 years, while lower than that of trunk fat for boys aged 14-15 years and girls aged 13-15 years. Conclusion Quantity and distribution of fat mass change with age around puberty, and the diversity is significant between boys and girls. 12 and 10 years old are the accelerating phases for central distribution of fat for male and female respectively.