title: Comparative strategies for using cluster analysis to assess dietary patterns.
abstract: OBJECTIVE
  To characterize dietary patterns using two different cluster analysis strategies.
  
  
  METHODS
  In this cross-sectional study, diet information was assessed by five 24-hour recalls collected over 10 months. All foods were classified into 24 food subgroups. Demographic, health, and anthropometric data were collected via home visit.
  
  
  METHODS
  One hundred seventy-nine community-dwelling adults, aged 66 to 87 years, in rural Pennsylvania.
  
  
  METHODS
  Cluster analysis was performed.
  
  
  RESULTS
  The methods differed in the food subgroups that clustered together. Both methods produced clusters that had significant differences in overall diet quality as assessed by Healthy Eating Index (HEI) scores. The clusters with higher HEI scores contained significantly higher amounts of most micronutrients. Both methods consistently clustered subgroups with high energy contribution (eg, fats and oils and dairy desserts) with a lower HEI score. Clusters resulting from the percent energy method were less likely to differentiate fruit and vegetable subgroups. The higher diet quality dietary pattern derived from the number of servings method resulted in more favorable weight status.
  
  
  CONCLUSIONS
  Cluster analysis of food subgroups using two different methods on the same data yielded similarities and dissimilarities in dietary patterns. Dietary patterns characterized by the number of servings method of analysis provided stronger association with weight status and was more sensitive to fruit and vegetable intake with regard to a more healthful dietary pattern within this sample. Public health recommendations should evaluate the methodology used to derive dietary patterns.
authors.affiliation: Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA 16801, USA. rkb119@psu.edu
authors.forename: Regan L
authors.initials: RL
authors.lastname: Bailey
authors.forename: Melissa D
authors.initials: MD
authors.lastname: Gutschall
authors.forename: Diane C
authors.initials: DC
authors.lastname: Mitchell
authors.forename: Carla K
authors.initials: CK
authors.lastname: Miller
authors.forename: Frank R
authors.initials: FR
authors.lastname: Lawrence
authors.forename: Helen
authors.initials: H
authors.lastname: Smiciklas-Wright
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D004032:Diet / Q000592:standards / Q000706:statistics & numerical data*; D004034:Diet Surveys; D005247:Feeding Behavior; D005260:Female; D005502:Food / Q000145:classification*; D005638:Fruit; D015577:Geriatric Assessment; D006304:Health Status; D006801:Humans; D008297:Male; D011939:Mental Recall; D015596:Nutrition Assessment; D010414:Pennsylvania; D011634:Public Health; D014675:Vegetables