title: Physical activity questionnaire for adolescents validated against doubly labelled water.
abstract: OBJECTIVE
  To validate a physical activity questionnaire for adolescents (PAQA) adapted from the International Physical Activity Questionnaire (IPAQ).
  
  
  METHODS
  Energy expenditure was measured during a 14-day period with doubly labelled water (DLW). PAQA was administered as an interview at the end of the period, asking for physical activity in school, during transportation and leisure-time, during a habitual week. Energy expenditure (EE(PAQA)) was calculated as the product of total physical activity + sleep and predicted resting metabolic rate, and was compared to energy expenditure from DLW (EE(DLW)), thermic effect of feeding excluded.
  
  
  METHODS
  Participants were recruited from grade 9 in a compulsory school in Göteborg, Sweden. All data were collected at school, and distribution of DLW and measuring of resting metabolic rate were performed at Sahlgrenska University Hospital.
  
  
  METHODS
  A total of 33 adolescents (16 girls, 17 boys) 15.7 (0.4) y performed all measurements.
  
  
  RESULTS
  : For the whole group, PAQA underestimated energy expenditure by 3.8 (1.7) MJ (P<0.001). There was a strong correlation (r = 0.62, P<0.001) between EE(PAQA) and EE(DLW), but not for boys (r = 0.42, P = 0.090) and girls (r = 0.33, P = 0.22) separately.
  
  
  CONCLUSIONS
  PAQA is not able to predict energy expenditure in Swedish adolescents, largely explained by the amount of unreported time. The ability to rank adolescents energy expenditure is questioned because of the gender effect, although we found a strong correlation for the whole group.
authors.affiliation: Department of Clinical Nutrition, Sahlgrenska Academy at Göteborg University, Göteborg, Sweden.
authors.forename: D
authors.initials: D
authors.lastname: Arvidsson
authors.forename: F
authors.initials: F
authors.lastname: Slinde
authors.forename: L
authors.initials: L
authors.lastname: Hulthèn
mesh_terms: D000293:Adolescent; D001481:Basal Metabolism / Q000502:physiology; D001834:Body Water / Q000378:metabolism*; D003903:Deuterium; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007899:Leisure Activities; D008297:Male; D015203:Reproducibility of Results; D012737:Sex Factors; D011795:Surveys and Questionnaires / Q000592:standards*
chemical_list: D003903:Deuterium