Self-rated quality of life measures: Effect of change to a low-fat, high-fiber, fruit and vegetable enriched diet

The Polyp Prevention Trial (PPT) was a multicenter randomized clinical tria l to determine the effect of a low-fat (20% of energy from fat), high-fiber (18 g/1000 kcal/day), high-fruit/vegetable (3.5 servings/1000 kcal/day) ea ting plan on the recurrence of large bowel adenomatous polyps. The PPT prov ided an opportunity to examine the impact of dietary changes on quality of life. At baseline and annually for 4 years, participants in the Quality of Life Substudy of PPT completed a Quality of Life Factors (QF) Questionnaire , a modified Block-National Cancer Institute Food Frequency Questionnaire, and a Health and Lifestyle Questionnaire. The 51-item QF Questionnaire asse ssed changes in nine domains: taste, convenience, cost, self-care, social, health assessment, health belief health action, and life satisfaction. The analysis compared annual changes in domain scores for intervention (n = 194 ) and control (n = 200) participants. At Year 1,363 (92%) completed a quest ionnaire, and 325 (82%) participants completed a Year 4 questionnaire. Ther e were no statistically significant differences between treatment groups in the change from baseline to Year I for the convenience, cost, taste, healt h assessment, and life satisfaction domains. At Year 1, intervention partic ipants rated the self-care (p < .001), health belief (p = .021), and health action (p < .001) domains significantly higher and the social domain signi ficantly lower (p < .001) than control participants, These changes were con sistent through Years 2, 3, and 4. This study provides evidence that, given appropriate support, five-living individuals can successfully alter their eatingpatterns in multiple ways without a negative impact on quality of lif e.