title: Rebound Body Mass Index Growth in Year-Round Elementary Education Students of Largely Hispanic Descent Undergoing Obesity Interventions.
abstract: BACKGROUND
  Body mass index (BMI) increases when students are away on summer vacation. Evaluation of serial BMI measurements on year-round students allows new insight into the reasons children gain weight seasonally.
  
  
  METHODS
  The 206 first and second graders of 2-year-round elementary schools with obesity intervention programs were weighed and measured every 6 months from April 2011 until April 2013. BMI and BMI percentiles were recorded.
  
  
  RESULTS
  Children <50th, 50th to 85th, and 85th to 95th BMI percentiles showed significant accelerated winter gains in BMI (p = 2.6 × 10(-7), p = 6.8 × 10(-10), and p = .0007, respectively) compared with the previous summers. Accelerated BMI growth of the second summer was absent when compared with the previous winter BMI changes in children <95th percentile (p = .48, p = .81, and p = .93). For children >95th percentile, BMI gain continued without significant changes year-round.
  
  
  CONCLUSIONS
  School-wide interventions to induce BMI growth limitations are associated with significant rebound BMI gain with possible wintertime augmentation in nonobese children of year-round education programs. Obese children do not display rebound BMI gain, BMI seasonal change, or BMI limitations in response to school-based interventions. School weight control programs should consider off-campus sources of weight gain and be vigilant for rebound and delayed seasonal BMI gains.
authors.affiliation: University of California, Riverside School of Medicine, School of Medicine Education Building, 900 University Avenue, Riverside, CA 92521. Andrew.Alexander@ucr.edu.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Alexander
authors.affiliation: Department of Family Medicine and Senior Associate Dean for Education, University of California, Riverside School of Medicine, School of Medicine Education Building, 900 University Avenue, Riverside, CA 92521. Paul.Lyons@ucr.edu.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Lyons
mesh_terms: D015992:Body Mass Index; D002140:California / Q000453:epidemiology; D002648:Child; D002657:Child Development; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D008297:Male; D009765:Obesity / Q000208:ethnology / Q000503:physiopathology*; D050177:Overweight / Q000208:ethnology / Q000503:physiopathology; D012572:School Health Services / Q000706:statistics & numerical data*; D012621:Seasons; D015430:Weight Gain
keywords: child and adolescent health; community health; growth and development; health educators; nutrition and diet; school food services