title: Longitudinal nutrient intake patterns of US adolescent women: the Penn State Young Women's Health Study.
abstract: OBJECTIVE
  To use longitudinal nutrient intake data to determine whether dietary patterns remain consistent (or "track") as U.S. females progress from age 12 to 18 years.
  
  
  METHODS
  Three-day diet records were collected at regular intervals over 6 years from participants in the Penn State Young Women's Health Study. Eighty-one subjects remained in the cohort during the study period. Tracking in body weight, in dietary intake of fat, sugar, iron, vitamin C, and in a total dietary score (TDS) was assessed using quartile-ranking analysis, year-to-year Pearson correlation analysis, and longitudinal linear analysis.
  
  
  RESULTS
  Rank analysis revealed that subjects maintained their relative quartile positions for body weight throughout the study period, and year-to-year correlation coefficients for this variable were .93-.94. In contrast, rank and correlation analyses showed that the subjects did not track strongly with respect to any nutrient variable. Age 12 to 18 years correlation coefficients ranged from r = .04 for fat intake to r = .15 for the TDS. In longitudinal linear models, slopes differed in direction and significance across the original quartiles for nutrient intake, indicating varying dietary trends over time within the study population.
  
  
  CONCLUSIONS
  Nutrient intake patterns do not track strongly throughout adolescence among U.S. females.
authors.affiliation: Department of Health Evaluation Sciences, College of Medicine and University Hospitals, Pennsylvania State University, Milton S. Hershey Medical Center, Hershey, USA.
authors.forename: D C
authors.initials: DC
authors.lastname: Cusatis
authors.forename: V M
authors.initials: VM
authors.lastname: Chinchilli
authors.forename: N
authors.initials: N
authors.lastname: Johnson-Rollings
authors.forename: K
authors.initials: K
authors.lastname: Kieselhorst
authors.forename: V A
authors.initials: VA
authors.lastname: Stallings
authors.forename: T
authors.initials: T
authors.lastname: Lloyd
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001205:Ascorbic Acid; D001835:Body Weight; D002648:Child; D004034:Diet Surveys; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D002149:Energy Intake; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D019266:Iron, Dietary; D016014:Linear Models; D008137:Longitudinal Studies; D010414:Pennsylvania; D016387:Women's Health
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D019266:Iron, Dietary; D001205:Ascorbic Acid