Direct and mediated effects of two theoretically based interventions to increase consumption of fruits and vegetables in the healthy body healthy spirit trial

Abdul R. Shaikh, Amiram D. Vinokur, Amy L. Yaroch, Geoffrey C. Williams, Ken Resnicow

Research output: Contribution to journalArticle

24 Scopus citations


This study tested the effects of two theory-based interventions to increase fruit and vegetable intake.Hypothesized intervention mediators included self-efficacy (SE), social support (SS), autonomous motivation (AM), and controlled motivation (CM).At baseline, 1,021 African American adults were recruited from 16 churches randomized to one comparison and two intervention groups: Group 1 (standard educational materials), Group 2 (culturally targeted materials), and Group 3 (culturally targeted materials and telephone-based motivational interviewing).A well-fitted model based on structural equation modeling-χ 2(df=541, N=353,325)=864.28, p<.001, normed fit index=.96,nonnormed fit index=.98, comparative fit index =.98,root mean square error of approximation=.042-demonstrated that AM was both a significant mediator and moderator.In the subgroup with low baseline AM, AM mediated 17% of the effect of the Group 3 intervention on fruit and vegetable intake.Conversely, SS, SE, and CM were not significant mediators.Implications related to theory and intervention development are discussed.

Original languageEnglish (US)
Pages (from-to)492-501
Number of pages10
JournalHealth Education and Behavior
Issue number5
Publication statusPublished - Oct 1 2011



  • African Americans
  • fruit and vegetable consumption
  • interaction effects
  • latent variable structural equation modeling
  • mediation analysis

ASJC Scopus subject areas

  • Arts and Humanities (miscellaneous)
  • Public Health, Environmental and Occupational Health

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