title: Prevalence of thinness in children and adolescents in the Seychelles: comparison of two international growth references.
abstract: BACKGROUND
  Thinness in children and adolescents is largely under studied, a contrast with abundant literature on under-nutrition in infants and on overweight in children and adolescents. The aim of this study is to compare the prevalence of thinness using two recently developed growth references, among children and adolescents living in the Seychelles, an economically rapidly developing country in the African region.
  
  
  METHODS
  Weight and height were measured every year in all children of 4 grades (age range: 5 to 16 years) of all schools in the Seychelles as part of a routine school-based surveillance program. In this study we used data collected in 16,672 boys and 16,668 girls examined from 1998 to 2004. Thinness was estimated according to two growth references: i) an international survey (IS), defining three grades of thinness corresponding to a BMI of 18.5, 17.0 and 16.0 kg/m2 at age 18 and ii) the WHO reference, defined here as three categories of thinness (-1, -2 and -3 SD of BMI for age) with the second and third named "thinness" and "severe thinness", respectively.
  
  
  RESULTS
  The prevalence of thinness was 21.4%, 6.4% and 2.0% based on the three IS cut-offs and 27.7%, 6.7% and 1.2% based on the WHO cut-offs. The prevalence of thinness categories tended to decrease according to age for both sexes for the IS reference and among girls for the WHO reference.
  
  
  CONCLUSIONS
  The prevalence of the first category of thinness was larger with the WHO cut-offs than with the IS cut-offs while the prevalence of thinness of "grade 2" and thinness of "grade 3" (IS cut-offs) was similar to the prevalence of "thinness" and "severe thinness" (WHO cut-offs), respectively.
authors.affiliation: Section of Noncommunicable Diseases, Ministry of Health, Victoria, Republic of Seychelles. pascal.bovet@chuv.ch
authors.forename: Pascal
authors.initials: P
authors.lastname: Bovet
authors.forename: Nathalie
authors.initials: N
authors.lastname: Kizirian
authors.forename: George
authors.initials: G
authors.lastname: Madeleine
authors.forename: Monika
authors.initials: M
authors.lastname: Blössner
authors.forename: Arnaud
authors.initials: A
authors.lastname: Chiolero
mesh_terms: D000293:Adolescent; D000367:Age Factors; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D003906:Developing Countries; D005260:Female; D006801:Humans; D008297:Male; D044342:Malnutrition / Q000453:epidemiology*; D009752:Nutritional Status; D009765:Obesity / Q000453:epidemiology*; D015995:Prevalence; D012016:Reference Values; D012737:Sex Factors; D012750:Seychelles / Q000453:epidemiology; D013851:Thinness / Q000453:epidemiology*; D014944:World Health Organization