title: Adolescent growth in overweight and non-overweight children in Japan: a multilevel analysis.
abstract: BACKGROUND
  A trend towards earlier pubertal growth has been identified along with an increase in childhood obesity rates. The study aimed to identify the differences in growth patterns during adolescence between overweight/obese and non-overweight children in Japan.
  
  
  METHODS
  The participants were children from a prospective cohort study called Project Koshu, who were born between 1991 and 1998, in Japan. They were classified as overweight/obese or non-overweight according to their body mass index (BMI) in the first grade of elementary school (6-7 years of age) and were followed until graduation from junior high school (14-15 years of age). Anthropometric data were collected at an annual medical check-up in their school. Height gain trajectories were constructed by BMI categories using multilevel analyses. This analysis was stratified by gender.
  
  
  RESULTS
  Overall, 111/850 (13.1%) girls and 109/911(12%) boys were defined as overweight/obese at baseline. Approximately 80% of the children were followed until the third grades of junior high school. Overweight/obese girls gained more height in the first half period, reached their peak height gain about a year earlier than non-overweight girls, and experienced an earlier decline in height gain. Similarly, overweight/obese boys gained more height than non-overweight boys initially. Additionally, non-overweight boys maintained a higher rate of height gain from the age at peak height gain, although the age at peak height gain did not differ between the two groups.
  
  
  CONCLUSIONS
  The overweight/obese children grew faster than the non-overweight children in the early pubertal stages, and the non-overweight children caught up and exceeded in height gain at a later stage.
authors.affiliation: Department of Health Sciences, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi, Japan.
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.forename: Kohta
authors.initials: K
authors.lastname: Suzuki
authors.forename: Miri
authors.initials: M
authors.lastname: Sato
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yokomichi
authors.forename: Ryoji
authors.initials: R
authors.lastname: Shinohara
authors.forename: Zentaro
authors.initials: Z
authors.lastname: Yamagata
mesh_terms: D000293:Adolescent; D001823:Body Composition; D001827:Body Height; D015992:Body Mass Index; D002648:Child; D002657:Child Development / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan; D008297:Male; D055361:Multilevel Analysis; D050177:Overweight; D011446:Prospective Studies; D012574:Schools; D012737:Sex Factors; D012741:Sexual Maturation / Q000502:physiology*
keywords: body mass index; height gain; puberty