title: Assessing dietary intake during the transition to adulthood: a comparison of age-appropriate FFQ for youth/adolescents and adults.
abstract: OBJECTIVE
  Assessing changes in dietary intake during the transition from adolescence to adulthood is challenging given the need for age-appropriate tools at different developmental stages. The present study investigated the comparability of intake estimates as assessed with the youth/adolescent and adult forms of Willett's FFQ.
  
  
  METHODS
  Young adults were first asked to complete the adult FFQ as part of a larger study, Project EAT-III (Eating and Activity in Teens and Young Adults). A stratified random sample of respondents was invited to complete the youth/adolescent FFQ by mail within a 3-week period.
  
  
  METHODS
  Participants were members of a longitudinal cohort who completed baseline surveys (including the adolescent FFQ) at schools in Minneapolis/St. Paul, Minnesota and completed Project EAT-III surveys online or by mail in 2008-2009.
  
  
  METHODS
  There were ninety-one men and 103 women (median age = 24·6 years) who completed both forms of the FFQ.
  
  
  RESULTS
  The adolescent and adult forms did not provide comparable absolute intake estimates. However, with few exceptions, correlation coefficients between intake estimates were moderate (r = 0·4-0·6). Furthermore, the percentage of individuals classified into the same quartile rank category based on their responses to the adolescent and adult forms was ≥50 % for fibre, vitamins A and E, and servings of fruit (excluding juice), vegetables, dairy, whole grains and soft drinks.
  
  
  CONCLUSIONS
  Although responses on the adolescent and adult FFQ cannot be compared to describe changes in absolute intake over time, these tools provide comparable intake rankings and may be used together in longitudinal studies to investigate influences on diet.
authors.affiliation: Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, 1300 South Second Street, Suite 300, Minneapolis, MN 55454, USA. larsonn@umn.edu
authors.forename: Nicole
authors.initials: N
authors.lastname: Larson
authors.forename: Lisa
authors.initials: L
authors.lastname: Harnack
authors.forename: Dianne
authors.initials: D
authors.lastname: Neumark-Sztainer
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D004032:Diet / Q000523:psychology / Q000592:standards / Q000706:statistics & numerical data*; D005247:Feeding Behavior / Q000523:psychology*; D005260:Female; D005518:Food Preferences / Q000523:psychology*; D015438:Health Behavior; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D015596:Nutrition Assessment; D009749:Nutrition Surveys; D009747:Nutritional Physiological Phenomena / Q000502:physiology*; D011795:Surveys and Questionnaires; D055815:Young Adult