title: Infancy and childhood growth and physical activity in adolescence: prospective birth cohort study from Brazil.
abstract: BACKGROUND
  The Developmental Origins of Health and Disease hypothesis suggests that intrauterine, infancy and early childhood variables play a key role at programming later health. However, little is known on the programming of behavioral variables, because most studies so far focused on chronic disease-related and human capital outcomes. The aim of the present study was to evaluate the effects of prenatal, infancy and childhood weight and length/height gains on objectively-measured physical activity (PA) in adolescence.
  
  
  METHODS
  This is a prospective birth cohort study in Pelotas, Brazil, including 457 adolescents (mean age: 13.3 years) with weight and length/height data at birth, one, three and six months, one and four years of age. PA was measured using a GT1M Actigraph accelerometer, and expressed as (a) minutes per day spent on sedentary, light, moderate, vigorous and very-vigorous activities; (b) total counts per day.
  
  
  RESULTS
  61.3% of the adolescents accumulated 60+ minutes of moderate-to-vigorous PA per day. Weight and length/height trajectories in infancy and childhood were similar between those classified as active or inactive at 13.3 years. However, those classified as inactive were heavier and taller at all ages; differences were statistically significant only in terms of length at three, six and 12 months.
  
  
  CONCLUSIONS
  Weight gain in infancy and childhood did not predict variability in adolescent PA, but those active in adolescence showed somewhat smaller average gains in length in infancy. These findings suggest that PA may partially be sensitive to early hormonal programming, or that genetic factors may affect both early growth and later metabolism or predisposition for PA.
authors: Federal University of Pelotas, Rua Marechal Deodoro 1160, 96020-220, Pelotas, Brazil. prchallal@gmail.com
authors: Pedro C
authors: PC
authors: Hallal
authors: Samuel C
authors: SC
authors: Dumith
authors: Ulf
authors: U
authors: Ekelund
authors: Felipe F
authors: FF
authors: Reichert
authors: Ana M B
authors: AM
authors: Menezes
authors: Cesar G
authors: CG
authors: Victora
authors: Jonathan C K
authors: JC
authors: Wells
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D001724:Birth Weight; D001827:Body Height; D015992:Body Mass Index; D001938:Brazil; D002648:Child; D005260:Female; D015438:Health Behavior; D006801:Humans; D016014:Linear Models; D008297:Male; D009043:Motor Activity; D011446:Prospective Studies; D057566:Self Report; D012959:Socioeconomic Factors; D015430:Weight Gain