Purpose: To assess efficacy of an intervention delivered by an interactive, computer-controlled telephone system to improve individuals' diets.
Design: Randomized controlled trial.
Setting: Large multispecialty group practice.
Subjects: Two hundred ninety-eight adults who were both sedentary and had suboptimal diet quality.
Intervention: Weekly communication for 6 months via a totally automated, computer-based voice system. Among intervention group subjects, the system monitored dietary habits and provided educational feedback, advice, and behavioral counseling. Control group subjects received physical activity promotion counseling.
Measures: Daily intake of fruits, vegetables, red and processed meats, whole fat dairy foods, and whole grain foods estimated from a food frequency questionnaire.
Results: Mean age 45.9 years, 72% women, 45% white, and 45% African-American. Among participants who completed diet assessments, compared with the control group, the intervention raised fruit intake a mean of 1.1 servings per day (95% confidence interval [CI] .4, 1.7). On a 0 to 100 global diet quality score combining all five food groups, intervention participants improved their mean score 9 (95% CI 4, 13) points more than in the control group. The intervention also raised dietary fiber intake 4.0 g/d (95% CI .1, 7.8) and decreased saturated fat, as a proportion of energy intake, by 1.7% (95% CI -2.7, -.7).
Conclusions: This computer-based telecommunications dietary behavior intervention helped improve participants' overall diet.