title: Trends in body mass index and prevalence of extreme high obesity among Pennsylvania children and adolescents, 2007-2011: promising but cautionary.
abstract: OBJECTIVE
  We determined current trends and patterns in overweight, obesity, and extreme high obesity among Pennsylvania pre-kindergarten (pre-K) to 12th grade students and simulated future trends.
  
  
  METHODS
  We analyzed body mass index (BMI) of pre-K to 12th grade students from 43 of 67 Pennsylvania counties in 2007 to 2011 to determine trends and to discern transition patterns among BMI status categories for 2009 to 2011. Vinsem simulation, confirmed by Markov chain modeling, generated future prevalence trends.
  
  
  RESULTS
  Combined rates of overweight, obesity, and extreme high obesity decreased among secondary school students across the 5 years, and among elementary students, first increased and then markedly decreased. BMI status remained constant for approximately 80% of normal and extreme high obese students, but both decreased and increased among students who initially were overweight and obese; the increase in BMI remained significant.
  
  
  CONCLUSIONS
  Overall trends in child and adolescent BMI status seemed positive. BMI transition patterns indicated that although overweight and obesity prevalence leveled off, extreme high obesity, especially among elementary students, is projected to increase substantially over time. If current transition patterns continue, the prevalence of overweight, obesity, and extreme high obesity among Pennsylvania students in 2031 is projected to be 16.0%, 6.6%, and 23.2%, respectively.
authors: David Lohrmann and Wasantha Jayawardene are with the Department of Applied Health Science, Indiana University School of Public Health-Bloomington. Ahmed YoussefAgha is with the Department of Epidemiology and Biostatistics, Indiana University School of Public Health-Bloomington.
authors: David
authors: D
authors: Lohrmann
authors: Ahmed
authors: A
authors: YoussefAgha
authors: Wasantha
authors: W
authors: Jayawardene
mesh_terms: D000293:Adolescent; D000367:Age Factors; D015992:Body Mass Index; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000453:epidemiology; D009767:Obesity, Morbid / Q000453:epidemiology*; D050177:Overweight / Q000453:epidemiology; D010414:Pennsylvania / Q000453:epidemiology; D015995:Prevalence; D012574:Schools / Q000706:statistics & numerical data