title: Profiles of body mass index and the nutritional status among children and adolescents categorized by waist-to-height ratio cut-offs.
abstract: BACKGROUND
  Waist-to-height ratio (WHtR) is proposed as a simple, valid and convenient measure of abdominal obesity and health risks in practice. The present study examined the distribution of nutritional status among children and adolescents categorized by WHtR cut-offs.
  
  
  METHODS
  A total of 30,459 students (15,249 boys and 15,210 girls) aged 7-18years participated in the study. Height, weight and waist circumference (WC) of all subjects were measured, body mass index (BMI) and WHtR were calculated. The grades of nutritional status (thinness, normal weight, overweight and obesity) was defined by the international BMI cut-offs. All subjects were divided into three groups (low, moderate and high) according to their WHtR, BMI level and the distribution of nutritional status among the three groups were compared.
  
  
  RESULTS
  In both boys and girls, significant differences in BMI level and the nutritional status were observed among the three groups. Children and adolescents aged 7-18years in the 'high WHtR group' (≥0.5) had higher BMI than those in the 'low WHtR group' (<0.4) by 6.00-10.15kg/m2for boys and 5.24-9.51kg/m2for girls. 'low WHtR group' had higher prevalence of thinness, and 'high WHtR group' had higher prevalence of overweight and obesity. The optimal distribution of nutritional status is found in the 'moderate WHtR group' (between 0.4 and 0.5) with the highest proportion of normal weight and low prevalence of thinness and obesity.
  
  
  CONCLUSIONS
  WHtR is associated with nutritional status, which could be an indicator of nutritional status and early health risk. It is necessary to develop optimal boundary values in the future.
authors.affiliation: Shandong Center for Disease Control and Prevention, Shandong University Institute of Preventive Medicine, Shandong, China. Electronic address: sdcdczyx@163.com.
authors.forename: Ying-Xiu
authors.initials: YX
authors.lastname: Zhang
authors.affiliation: Yantai Center for Disease Control and Prevention, Shandong, China.
authors.forename: Zhao-Xia
authors.initials: ZX
authors.lastname: Wang
authors.affiliation: Shandong Center for Disease Control and Prevention, Shandong University Institute of Preventive Medicine, Shandong, China.
authors.forename: Zun-Hua
authors.initials: ZH
authors.lastname: Chu
authors.affiliation: Shandong Center for Disease Control and Prevention, Shandong University Institute of Preventive Medicine, Shandong, China.
authors.forename: Jin-Shan
authors.initials: JS
authors.lastname: Zhao
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D009752:Nutritional Status / Q000502:physiology*; D056128:Obesity, Abdominal / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D050177:Overweight / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D013851:Thinness / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D055105:Waist Circumference / Q000502:physiology*; D065927:Waist-Height Ratio
keywords: Adolescent; Body mass index; Child; Nutritional status; Waist-to-height ratio