A randomized trial of a tailored, self-help dietary intervention: the Puget Sound Eating Patterns study.

Abstract

This study evaluated a tailored, multiple-component self-help intervention designed to promote lower fat and higher fruit and vegetable consumption. Participants were 1,459 adults selected at random, stratified by sex and age (18-34, 35-54, 55-69), from enrollees of a large health maintenance organization. After completing a baseline telephone survey, participants were randomized to receive the intervention (consisting of a computer-generated personalized letter, a motivational phone call, a self-help manual, a package of supplementary materials, computer-generated behavioral feedback based on a self-administered food frequency questionnaire, and newsletters) or to receive no materials. Evaluation was based on 1,205 (86.5%) participants who completed both a 3- and a 12-month follow up survey. The intervention effect +/- SE for fat, based on a diet habits questionnaire, was -0.10 +/- 0.02 (P < 0.001), corresponding to a reduction of approximately 0.8 percentage points of percentage energy from fat. For fruits and vegetables, the intervention effect was 0.47 +/- 0.10 servings/day (P < 0.001). Intervention effects were similar across age and sex groups. Tailored, self-help interventions can effectively promote dietary change among both men and women and among younger as well as older adults.