title: Thinness in the era of obesity: trends in children and adolescents in The Netherlands since 1980.
abstract: BACKGROUND
  Although children both at the upper and lower tail of the body mass index (BMI) distribution are at greater health risk, relatively little is known about the development of thinness prevalence rates in developed countries over time. We studied trends in childhood thinness and assessed changes in the BMI distribution since the onset of the obesity epidemic.
  
  
  METHODS
  Growth data from 54 814 children aged 2-18 years of Dutch, Turkish and Moroccan origin living in The Netherlands were used. Anthropometric measurements were performed during nationwide cross-sectional growth studies in 1980 (only Dutch), 1997 and 2009. Prevalence rates of thinness grades I, II and III were calculated according to international cut-offs. BMI distributions for 1980, 1997 and 2009 were compared.
  
  
  RESULTS
  Since 1980, thinness (all grades combined) reduced significantly from 14.0% to 9.8% in children of Dutch origin, but the proportion of extremely thin children (grade III) remained constant. Thinness in children of Moroccan origin decreased significantly from 8.8% to 6.2% between 1997 and 2009. No significant difference was observed in children of Turkish origin (5.4% in 1997 vs. 5.7% in 2009). Thinness occurred most often in children aged 2-5 years. There were no differences between boys and girls. The BMI distribution widened since 1980, mainly due to an upward shift of the upper centiles.
  
  
  CONCLUSIONS
  Since the onset of the obesity epidemic, prevalence rates of thinness decreased. However, we found a small but persistent group of extremely thin children. More research is needed to gain insight into their health status.
authors.affiliation: 1 Department of Child Health, Netherlands Organisation for Applied Scientific Research (TNO), Leiden, The Netherlands yvonne.schonbeck@tno.nl.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Schönbeck
authors.affiliation: 2 Department of Life Style, Netherlands Organisation for Applied Scientific Research (TNO), Leiden, The Netherlands.
authors.forename: Paula
authors.initials: P
authors.lastname: van Dommelen
authors.affiliation: 3 EMGO Institute of Health Care Research, VU University Medical Centre Amsterdam, Amsterdam, The Netherlands.
authors.forename: Remy A
authors.initials: RA
authors.lastname: HiraSing
authors.affiliation: 2 Department of Life Style, Netherlands Organisation for Applied Scientific Research (TNO), Leiden, The Netherlands 4 Department of Methodology and Statistics, FSS, University of Utrecht, Utrecht, The Netherlands.
authors.forename: Stef
authors.initials: S
authors.lastname: van Buuren
mesh_terms: D000293:Adolescent; D000367:Age Factors; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D015995:Prevalence; D013851:Thinness / Q000453:epidemiology*