A Randomized Trial of a Tailored, Self-Help Dietary Intervention: The Puget Sound Eating Patterns Study

Background. This study evaluated a tailored, multiple-component self-help intervention designed to promote lower fat and higher fruit and vegetable consumption. Methods. 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. Results. 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. Conclusions. Tailored, self-help interventions can effectively promote dietary change among both men and women and among younger as well as older adults.