title: Validated scales to assess adult self-efficacy to eat fruits and vegetables.
abstract: OBJECTIVE
  An audience-centered approach was used to develop valid and reliable scales to measure adult self-efficacy to eat fruit and vegetables.
  
  
  METHODS
  Cross-sectional survey of a national population.
  
  
  METHODS
  New Zealand.
  
  
  METHODS
  A sample of 350 adults ages 25 to 60 years was randomly selected from a nationally representative sampling frame. Overall, 231 questionnaires were returned, producing a 72% response rate. The mean age of subjects was 42.7years; 58% were female; 80% were of European descent; 11% were indigenous Maori.
  
  
  METHODS
  The 76-item, self-administered questionnaire collected data on demographics, fruit and vegetable intakes, stages of change, decisional balance, and self-efficacy (24 items).
  
  
  METHODS
  Principal components analysis with oblimin rotation was performed.
  
  
  RESULTS
  Principal components analysis yielded three distinct and reliable scales for self-efficacy to eat "vegetables," "fruit," and "fruit and vegetables" (Cronbach alpha = .80, .85, and .73, respectively). These scales were correlated, but only the "vegetable" scale was positively correlated with the "fruit and vegetable" scale (Kendall tau r = 0.30, -0.26 [fruit, "fruit and vegetables"], -0.38 [fruit, vegetable]). As predicted, self-efficacy was associated with intake (r = 0.30 [fruit], 0.34 [vegetables]).
  
  
  CONCLUSIONS
  Assuming the factor structure is confirmed in independent samples, these brief psychometrically sound scales may be used to assess adult self-efficacy to eat fruit and to eat vegetables (separately) but not self-efficacy to eat "fruit and vegetables."
authors.affiliation: Department of Human Nutrition, University of Otago, Dunedin, New Zealand. louise.mainvil@otago.ac.nz
authors.forename: Louise A
authors.initials: LA
authors.lastname: Mainvil
authors.forename: Rob
authors.initials: R
authors.lastname: Lawson
authors.forename: Caroline C
authors.initials: CC
authors.lastname: Horwath
authors.forename: Joanne E
authors.initials: JE
authors.lastname: McKenzie
authors.forename: Anthony I
authors.initials: AI
authors.lastname: Reeder
mesh_terms: D000328:Adult; D000367:Age Factors; D004034:Diet Surveys; D004522:Educational Status; D005163:Factor Analysis, Statistical; D005247:Feeding Behavior / Q000208:ethnology / Q000523:psychology*; D005260:Female; D005518:Food Preferences / Q000208:ethnology / Q000523:psychology*; D005638:Fruit; D015438:Health Behavior; D006801:Humans; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D011594:Psychometrics / Q000295:instrumentation*; D020377:Self Efficacy; D012737:Sex Factors; D011795:Surveys and Questionnaires / Q000592:standards*; D014675:Vegetables