title: Association of physical activity and dietary behaviours in relation to the body mass index in a national sample of Iranian children and adolescents: CASPIAN Study.
abstract: OBJECTIVE
  To examine the relation of dietary and physical activity (PA) patterns with the body mass index (BMI), and the associations between these patterns among children.
  
  
  METHODS
  A representative sample of 21 111 school students aged 6-18 years was selected by multistage random cluster sampling from 23 provinces in the Islamic Republic of Iran. PA and dietary pattern were assessed by self-administered validated questionnaires.
  
  
  RESULTS
  Fruit and vegetables, dairy products and snacks (salty, fatty or sweet) had a similar consumption frequency of approximately twice a day. The type of fat most frequently consumed was hydrogenated solid fat (consumed by 73.8% of families). The PA level was significantly higher among boys than girls, in rural than in urban residents, and in intermediate students than high-school students. Among boys, the frequency of consumption of vegetables and plant proteins (R(2) = 0.46); and among girls, the frequency of consumption of dairy products and fruits, as well as high PA level had a significant inverse association with BMI (R(2) = 0.57). Among boys, the low frequency of consumption of fruits, the time spent on PA and the energy expenditure; and among girls, the time spent on PA and the energy expenditure, had significant relationships with overweight. When controlling for covariates, PA levels had significant relationships with the frequency of consumption of all food groups.
  
  
  CONCLUSIONS
  Unhealthy lifestyles make Iranian young people prone to chronic diseases later in life. When examining their health benefits, the interrelationship of dietary and PA behaviours should be considered.
authors.affiliation: Preventive Pediatric Cardiology Department, Isfahan Cardiovascular Research Centre, Isfahan University of Medical Sciences, Isfahan, Islamic Republic of Iran. Kelishadi@med.mui.ac.ir
authors.forename: Roya
authors.initials: R
authors.lastname: Kelishadi
authors.forename: Gelayol
authors.initials: G
authors.lastname: Ardalan
authors.forename: Riaz
authors.initials: R
authors.lastname: Gheiratmand
authors.forename: Mohammad Mehdi
authors.initials: MM
authors.lastname: Gouya
authors.forename: Emran Mohammad
authors.initials: EM
authors.lastname: Razaghi
authors.forename: Alireza
authors.initials: A
authors.lastname: Delavari
authors.forename: Reza
authors.initials: R
authors.lastname: Majdzadeh
authors.forename: Ramin
authors.initials: R
authors.lastname: Heshmat
authors.forename: Molouk
authors.initials: M
authors.lastname: Motaghian
authors.forename: Hamed
authors.initials: H
authors.lastname: Barekati
authors.forename: Minou Sadat
authors.initials: MS
authors.lastname: Mahmoud-Arabi
authors.forename: Mohammad Mehdi
authors.initials: MM
authors.lastname: Riazi
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D004032:Diet / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D009043:Motor Activity; D012737:Sex Factors; D012959:Socioeconomic Factors