title: Human body shape index based on an experimentally derived model of human growth.
abstract: OBJECTIVE
  To test the assumption of geometrically similar growth by developing experimentally derived models of human body growth during the age interval of 5 to 18 years; to use these derived growth models to establish a new human body shape index (HBSI) based on natural age-related changes in human body shape (HBS); and to compare various metrics of relative body weight (body mass index [BMI], ponderal index [PI], and HBSI) in a sample of 5- to 18-year-old children.
  
  
  METHODS
  Nondisabled Polish children (n = 847) participated in this descriptive study. To model growth, the best fit between body height (H) and body mass (M) was calculated for each sex using the allometric equation M = m(i) H(chi). HBSI was calculated separately for girls and boys, using sex-specific values for chi and a general HBSI from combined data. The customary BMI and PI were calculated and compared with HBSI values.
  
  
  RESULTS
  The models of growth were M = 13.11H(2.84) (R2 = 0.90) for girls and M = 13.64H(2.68) (R2 = 0.91) for boys. HBSI values contained less inherent variability and were less influenced by growth (age and height) compared with BMI and PI.
  
  
  CONCLUSIONS
  Age-related growth during childhood is sex-specific and not geometrically similar. Therefore, indices of HBS formulated from experimentally derived models of human growth are superior to customary geometric similarity-based indices for characterizing HBS in children during the formative growth years.
authors.affiliation: Physical Disabilities Branch, National Institutes of Health, Bethesda, MD, USA. lebiedowskam@cc.nih.gov
authors.forename: Maria K
authors.initials: MK
authors.lastname: Lebiedowska
authors.forename: Katharine E
authors.initials: KE
authors.lastname: Alter
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Stanhope
mesh_terms: D000293:Adolescent; D001827:Body Height; D015992:Body Mass Index; D049628:Body Size; D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D050177:Overweight / Q000453:epidemiology; D011044:Poland / Q000453:epidemiology; D012016:Reference Values; D012044:Regression Analysis; D012727:Sex Characteristics; D013851:Thinness / Q000453:epidemiology