title: Synergistic effects of social support and self-efficacy on dietary motivation predicting fruit and vegetable intake.
abstract: BACKGROUND
  Self-efficacy and social support are considered relevant predictors of fruit and vegetable intake. This study examines whether the effect of self-efficacy on fruit and vegetable intake is mediated by intention and whether this motivational process is moderated by received dietary social support.
  
  
  METHODS
  A longitudinal study with two measurement points in time, four weeks apart, on fruit and vegetable intake was carried out with 473 students aged 19 years on average (52% women). In a conditional process analysis, dietary intention was specified as a mediator between self-efficacy and fruit and vegetable intake, whereas received dietary support was specified as a moderator of the self-efficacy-intention association, controlling for baseline fruit and vegetable intake.
  
  
  RESULTS
  Self-efficacy was positively associated with fruit and vegetable intake four weeks later, and intention mediated this process. Moreover, an interaction between received dietary support and self-efficacy on intention emerged.
  
  
  CONCLUSIONS
  The effect of self-efficacy on fruit and vegetable intake was fully mediated by intention. Moreover, received support exhibited a moderating role within the motivational process: high dietary support appeared to accentuate the positive relationship between self-efficacy and dietary intention.
authors.affiliation: Freie Universität Berlin, Germany; Universidad de Costa Rica, Costa Rica. Electronic address: benjamin.reyes-fernandez@fu-berlin.de.
authors.forename: Benjamín
authors.initials: B
authors.lastname: Reyes Fernández
authors.affiliation: Freie Universität Berlin, Germany; German Centre of Gerontology, Berlin, Germany.
authors.forename: Lisa Marie
authors.initials: LM
authors.lastname: Warner
authors.affiliation: Freie Universität Berlin, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Knoll
authors.affiliation: Universidad de Costa Rica, Costa Rica.
authors.forename: Esteban
authors.initials: E
authors.lastname: Montenegro Montenegro
authors.affiliation: Institute for Positive Psychology and Education, Australian Catholic University, Sydney, NSW, Australia; University of Social Sciences and Humanities, Wroclaw, Poland.
authors.forename: Ralf
authors.initials: R
authors.lastname: Schwarzer
mesh_terms: D000328:Adult; D004032:Diet; D005247:Feeding Behavior; D005260:Female; D005638:Fruit; D015438:Health Behavior; D006801:Humans; D033182:Intention; D008137:Longitudinal Studies; D008297:Male; D009042:Motivation; D020377:Self Efficacy; D012944:Social Support; D013334:Students; D011795:Surveys and Questionnaires; D014675:Vegetables; D055815:Young Adult
keywords: Dietary behavior; Intention; Motivation; Self-efficacy; Social support