Background: Adherence to dietary recommendations for disease management is often hindered by the complexity of incorporating them into the daily diet. Nutrition and cardiovascular scientists anti food technologists collaborated to develop a prepared meal plan that meets national dietary guidelines for cardiovascular risk reduction. Objective: To assess the clinical effects of this plan, which incorporates all National Academy of Sciences National Research Council recommended dietary allowances for vitamins, minerals, and macronutrients, compared with a patient-selected American Heart Association Step I anti Step II diet plan. Methods: This multicenter, randomized, parallel-intervention trial was conducted at 10 medical centers in the United States and Canada and involved 560 men and women with hypertension, dyslipidemia, or diabetes. Following calculation of prescriptions to meet individual nutritional requirements based on the Harris Benedict equation, participants were randomized to the Campbell's Center for Nutrition and Wellness (CCNW) plan, which is composed of prepackaged breakfast, lunch, and dinner meals provided to participants, or a nutritionist-guided American Heart Association Step I and Step II diet, in which participants self-selected foods to meet their nutrition prescription for 10 weeks. Main Outcome Measures: Blood pressure (BP); lipid, glucose, glycosylated hemoglobin (HbA(1c)), and insulin levels; body weight: dietary intake; and quality of life. Results: Patients' BP, lipid levels, carbohydrate metabolism, weight, and quality of life (P≤.001 for all findings except low-density lipoprotein-high-density lipoprotein ratio, P=.25) all improved on both nutrition plans. Mean differences (±SD) between baseline and treatment clinical values for the CCNW and the self-selected diet groups (between-group P values), respectively, were as follows: systolic BP, -6.4±9.2 mm Hg and -4.6±9.0 mm Hg (P=.02); diastolic BP, -4.2±5.7 mm Hg and -3.0±5.1 mm Hg (P=.006); cholesterol, -0.32±0.58 mmol/L and - 0.27±0.56 mmol/L (-12.4±22.5 mg/dL and -10.4±21.9 mg/dL) (P=.30); glucose, -0.65±1.88 mmol/L and -0.75±2.03 mmol/L (-11.7±34.0 mg/dL and -13.5±36.6 mg/dL) (P=.10); and HbA(1c), -0.4%±0.8% and 0.3%±0.7% (P=.66). Weight loss with the CCNW and self-selected plans, respectively, was as follows: men, - 4.5±3.6 kg and 3.5±3.3 kg; and women, -4.8±3.0 kg and -2.8±2.8 kg. Quality of life was significantly improved for daily and work activities (P<.05) and nutritional health perceptions (P<.05) with the CCNW plan relative to the self-selected group. Overall nutrient intake and compliance were both significantly (P<.001) better with the CCNW plan. Conclusions: Nutritionally balanced meals that meet the recommendations of national health organizations improved multiple risk factors for patients with cardiovascular disease. The CCNW plan resulted in greater clinical benefits, nutritional completeness, and compliance than the self-selected diet. The CCNW is a comprehensive nutrition plan, convenient for both prescription anti practice, and appears viable for effecting favorable dietary changes in patients at high risk for cardiovascular disease.