Psychosocial predictors of fruit and vegetable consumption in adults a review of the literature.

BACKGROUND: Adequate fruit and vegetable intake has been found to promote health and reduce the risk of several cancers and chronic diseases. Understanding the psychological determinants of fruit and vegetable intake is needed to design effective intervention programs.
METHODS: Papers published in English from 1994 to 2006 that described the relationship between psychosocial predictors and fruit and vegetable intake in adults were reviewed. Studies and their constructs were independently rated based on the direction of significant effects, quality of execution, design suitability, and frequency. Methodology from the Guide to Community Preventive Services was used to systematically review and synthesize findings.
RESULTS: Twenty-five psychosocial constructs spanning 35 studies were reviewed (14 prospective and 21 cross-sectional/descriptive studies). Strong evidence was found for self-efficacy, social support, and knowledge as predictors of adult fruit and vegetable intake. Weaker evidence was found for variables including barriers, intentions, attitudes/beliefs, stages of change, and autonomous motivation.
CONCLUSIONS: The findings underscore the need to design future behavioral interventions that use strong experimental designs with efficacious constructs and to conduct formal mediation analyses to determine the strength of these potential predictors of fruit and vegetable intake.