Implementation intentions; Fruit and vegetable intake; Low socioeconomic status; Theory of Planned Behavior, Public housing


Fruit and vegetable intake (FVI), a modifiable risk factor for chronic diseases, is lower in low socioeconomic status (SES) populations. Implementation intentions (a specific type of planning that extends the Theory of Planned Behavior) has been studied to improve FVI, but not exclusively with low SES groups. Using mixed methods, we evaluated the feasibility, acceptability, and preliminary efficacy of an implementation intention intervention (versus a general plan) to increase FVI in women with low SES. For the pilot randomized controlled trial, demographics, body mass index, attitude, perceived behavioral control, goal intention strength, and FVI were measured at baseline and FVI again 1-month following the intervention. Feasibility data were collected for recruitment, randomization, retention, and assessment procedures and compared to predetermined targets. Semi-structured interview data was analyzed for emergent themes regarding acceptability of the trial. Preliminary efficacy of the intervention to improve FVI was analyzed descriptively. Feasibility targets were met for randomization (100% vs. ≥80% target), retention (93.5% vs. ≥70% target) and the assessment metrics missing data points (2% vs. ≤10% target) and days from intervention to follow up (mean=69.2, sd=42.6 vs.days). Targets for recruitment were not met with the exception of participants giving informed consent (100% vs. ≥70% target). Participants described the intervention as enjoyable and reported behavioral constructs outside of those measured as important to improve FVI. Limited efficacy analysis suggested that both groups increased their FVI (experimental: +0.17 servings per day, 95% CI: -0.85, 1.20; control: +0.50 servings per day, 95% CI: -0.56, 1.58). Further research which examines interventions based upon behavior change models to improve dietary health behaviors in marginalized groups is needed.