title: Longitudinal changes in the accuracy of reported energy intake in girls 10-15 y of age.
abstract: BACKGROUND
  Dietary records are often used to estimate individual energy needs and population energy requirements. However, significant underreporting of total energy intake (EI) has been found when EI is compared with total energy expenditure (EE) measured by doubly labeled water.
  
  
  OBJECTIVE
  This study aimed to determine whether the accuracy of reported EI decreases from middle childhood to adolescence.
  
  
  METHODS
  In this longitudinal study of 26 healthy girls, EI and EE were measured at ages 10, 12, and 15 y. Accuracy of reported EI (EI/EE x 100%) was calculated at each age. At study entry, girls had a mean (+/- SD) body mass index (in kg/m(2)) of 16.8 +/- 1.9 and percentage body fat of 24.0 +/- 4.6%. Measurements of EI were a 7-d dietary record and those of EE were by doubly labeled water.
  
  
  RESULTS
  As they got older, girls tended to report EI less accurately: the average accuracy was 88 +/- 13% at age 10 y, 77 +/- 21% at age 12 y, and 68 +/- 17% at age 15 y. The declines in reporting accuracy from age 10 y to age 12 y and from age 10 y to age 15 y were statistically significant (P = 0.03 and P = 0.001, respectively). Reporting accuracy also declined from age 12 to age 15 y but not significantly. When percentage body fat was added to the model, results were essentially unchanged.
  
  
  CONCLUSIONS
  Because of the decline in EI reporting accuracy with age, the use of EI data obtained from dietary records in adolescent girls will result in substantial underestimation of energy needs.
authors.affiliation: General Clinical Research Center, Massachusetts Institute of Technology, Cambridge, MA, USA. lbandini@bu.edu
authors.forename: Linda G
authors.initials: LG
authors.lastname: Bandini
authors.forename: Aviva
authors.initials: A
authors.lastname: Must
authors.forename: Helene
authors.initials: H
authors.lastname: Cyr
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Anderson
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Spadano
authors.forename: William H
authors.initials: WH
authors.lastname: Dietz
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001823:Body Composition; D002648:Child; D015930:Diet Records; D004435:Eating; D002149:Energy Intake / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D009751:Nutritional Requirements; D009765:Obesity / Q000517:prevention & control