title: Construct validity of a single-item, self-rated question of diet quality.
abstract: OBJECTIVE
  To provide evidence of the construct validity of a single-item overall diet question with a nomological network of self-rated and biometric measures of dietary intake and outcomes.
  
  
  METHODS
  The authors conducted a secondary analysis of survey and biometric data from a cross-sectional sample of urban-dwelling adults. In addition to self-rated diet quality, they examined dietary behaviors, biomarkers of intake, and related outcomes. Self-rated diet quality was treated as a continuous variable to calculate P for trend using regression analysis.
  
  
  RESULTS
  Self-rated diet quality was significantly associated with variation in both subjective and objective measures of dietary intake (fruit and vegetable intake, P < .001; sugar-sweetened beverage intake, P < .001; sodium to potassium ratio, P < .001), behavior (frequency of fast-food dining, P < .001), and related outcomes (systolic blood pressure, P = .010; diastolic blood pressure, P < .001; and body mass index, P < .001).
  
  
  CONCLUSIONS
  Evidence supports the construct validity of a single-item measure of diet quality. This single-item question may be a useful proxy for more burdensome measures of overall diet quality.
authors.affiliation: Yale School of Public Health, New Haven, CT. Electronic address: erikka.loftfield@yale.edu.
authors.forename: Erikka
authors.initials: E
authors.lastname: Loftfield
authors.affiliation: NYU School of Medicine in the Center for the Study of Asian American Health, New York, NY.
authors.forename: Stella
authors.initials: S
authors.lastname: Yi
authors.affiliation: New York City Department of Health and Mental Hygiene, New York, NY.
authors.forename: Stephen
authors.initials: S
authors.lastname: Immerwahr
authors.affiliation: New York City Department of Health and Mental Hygiene, New York, NY.
authors.forename: Donna
authors.initials: D
authors.lastname: Eisenhower
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D004034:Diet Surveys / Q000379:methods* / Q000592:standards*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009519:New York City / Q000453:epidemiology; D050177:Overweight / Q000453:epidemiology; D011634:Public Health; D012044:Regression Analysis; D011795:Surveys and Questionnaires / Q000592:standards*; D055815:Young Adult
keywords: diet surveys; health surveys; public health