title: Focused Principal Component Analysis: a graphical method for exploring dietary patterns.
abstract: The aim of the present study was to introduce Focused Principal Component Analysis (FPCA) as a novel exploratory method for providing insight into dietary patterns that emerge based on a given characteristic of the sample. To demonstrate the use of FPCA, we used a database of 1,968 adults. Food intake was obtained using a food frequency questionnaire covering 26 food items. The focus variables used for analysis were age, income, and schooling. All analyses were carried out using R software. The graphs generated show evidence of socioeconomic inequities in dietary patterns. Intake of whole-wheat foods, fruit, and vegetables was positively correlated with income and schooling, whereas for refined cereals, animal fats (lard), and white bread this correlation was negative. Age was inversely associated with intake of fast-food and processed foods and directly associated with a pattern that included fruit, green salads, and other vegetables. In an easy and direct fashion, FPCA allowed us to visualize dietary patterns based on a given focus variable.
authors.affiliation: Universidade do Vale do Rio dos Sinos, São Leopoldo, Brasil.
authors.forename: Raquel
authors.initials: R
authors.lastname: Canuto
authors.forename: Suzi
authors.initials: S
authors.lastname: Camey
authors.forename: Denise P
authors.initials: DP
authors.lastname: Gigante
authors.forename: Ana M B
authors.initials: AM
authors.lastname: Menezes
authors.forename: Maria Teresa Anselmo
authors.initials: MT
authors.lastname: Olinto
mesh_terms: D000328:Adult; D000368:Aged; D001938:Brazil; D003430:Cross-Sectional Studies; D004034:Diet Surveys / Q000379:methods / Q000706:statistics & numerical data*; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D025341:Principal Component Analysis; D012959:Socioeconomic Factors; D055815:Young Adult