Survey On Nutritional Status Among Middle School Students In Changsha And Establishment Of Body Mass Index Reference Norm For Screening Overweight And Obesity In Changsha Adolescents

Part One Survey on Nutritional Status of Middle school students in ChangshaObjective To investigate nuitritional status of middle schoolstudents in changsha, and to provide scientific evidence for exploringmeasures for intervention.Methods Four middle schools in Changsha urban area wererandomly selected and their students aged 11 to 18 years were recruitedto measure the body height and weight, and the nutritional status wasassessed by the method of weight for height.Results (1)There were higher prevalence of obesity(14.0%),underweight(40.9%), malnutrition(5.6%), but an unreasonable lower rateof normal body weight in Changsha adolescents in 2006. (2)The ratios ofobesity(17.8% vs 10%, P＜0.001 ), underweight(43.1% vs 18.6%,P＜0.001) and malnutrition(7.0% vs 4.1%, P＜0.001) was significantlyhigher in boy students than that of girl students. There were nosignificantly difference in ratios of overweight between the male studentsand female students(5.3% vs 5.2%, P=0.795).Conclusion The prevalence of obesity and malnutrition was sosevere that scientific and effective measures of intervention should betaken to control the disadvantageous complexion. Part two Investigation on body mass index andestablishment of a reference norm for screening overweightand obesity in Changsha adolescents aged 11-18 yearsObjective To investigate the distribution profile of body massindex and establish a reference norm for the purpose of screeningoverweight and obesity in Changsha adolescents aged 11-18 years.Methods Four middle schools in Changsha urban area wererandomly selected, the health survey data from 2004 to 2006 of studentsaged 11-18 years were collected. Analyzed the distribution pattem ofbody mass index, and compared it with the American NCHS BMI chartsand the chinese BMI norm.Results (1)All the BMI values of means, medians and centiles inmale students were significantly higher than those of female students.BMI values increased gradually with age. There was a sharp increaseduring 13-15 years and then slowed down afterwards. (2)Established theBMI norm, composed by cut-off points of P₈₅ for overweight and P₉₅ forobesity in Changsha adolescents. Compared with the American NCHSBMI charts, male's P₈₅, P₉₅ and female's P₈₅ were higher respectivelybefore 16.4, 15.5 and 12 years old and were lower afterwards. P₉₅ infemale adolescents was lower than the NCHS norm after 11 years old.Compared with the Chinese BMI norm, P₈₅ and P₉₅ were always higher inmale adolescents from 11-18 years. P₈₅ and P₉₅ in Changsha femaleadolescents were lower from 12.5 years old.Conclusion The BMI distribution profile in Changsha adolescentsaged 11-18 years was different from the NCHS and the Chinese BMIcharts. We suggests on adoption the new BMI reference norm forscreening and diagnosis of overweight and obesity in Changshaadolescents.