Characteristics of the diet patterns tested in the optimal macronutrient intake trial to prevent heart disease (OmniHeart): options for a heart-healthy diet.

OBJECTIVE: To describe the nutrient and food composition of the diets tested in the Optimal Macronutrient Intake Trial to Prevent Heart Disease (OmniHeart). DESIGN: Two center, randomized, three-period crossover, controlled feeding trial that tested the effects of three healthful diet patterns on blood pressure, serum lipid levels, and estimated cardiovascular risk. SUBJECTS/SETTING: One hundred sixty-four participants with prehypertension and hypertension. During the 19 weeks of feeding, participants were required to consume only food prepared as part of the trial. INTERVENTION: The OmniHeart trial studied three diet patterns that differed in macronutrient composition: a carbohydrate-rich diet similar to the Dietary Approaches to Stop Hypertension diet (58% carbohydrate, 15% protein, and 27% fat), a higher protein diet that had 10% more protein and 10% less carbohydrate (48% carbohydrate, 25% protein, and 27% fat), and a higher unsaturated fat diet that had 10% more unsaturated fat and 10% less carbohydrate (48% carbohydrate, 15% protein, and 37% fat). Each diet contained 6% saturated fat and 100 to 200 mg cholesterol. Sodium was 2,300 mg at the 2,100 kcal energy level and was indexed across energy levels. Calcium, magnesium, and potassium were consistent with recommendations for the Dietary Approaches to Stop Hypertension diet and also indexed to energy levels. Each diet pattern met the major nutrient recommendations set by the Dietary Guidelines for Americans 2005. The 10% protein increase in the higher protein diet emphasized plant protein; however, meat and dairy food sources were also increased somewhat. Olive oil, canola oil, and olive oil spread were used liberally to achieve the unsaturated fat content of the higher unsaturated fat diet. The 10% reduction in carbohydrate in the higher protein diet and the higher unsaturated fat diet was achieved by replacing some fruits with vegetables, reducing sweets, and using smaller portions of grain products. All three diets reduced blood pressure, total and low-density lipoprotein cholesterol levels, and estimated coronary heart disease risk. CONCLUSIONS: The OmniHeart diet patterns offer substantial flexibility in macronutrient intake that should make it easier to eat a heart-healthy diet and reduce cardiovascular disease risk.

PREMIER--a trial of lifestyle interventions for blood pressure control: intervention design and rationale.

Interventions encouraging adoption of healthy diets and increased physical activity are needed to achieve national goals for preventing and treating hypertension, cardiovascular disease, diabetes, and other chronic diseases. PREMIER was a multicenter clinical trial testing the effects of two lifestyle interventions on blood pressure control, compared with advice only. Both interventions implemented established national guidelines for blood pressure control (weight loss, reduced sodium and alcohol intake, and increased physical activity), and one intervention also included the Dietary Approaches to Stop Hypertension (DASH) diet. Both interventions focused on behavioral self-management, motivational enhancement, and personalized feedback. This article describes the design and evaluation approaches for these interventions. Evaluation of multicomponent lifestyle change interventions can help us understand the benefits and difficulties of making multiple lifestyle changes concurrently and the effects such changes can have on blood pressure, particularly in minorities at higher risk for hypertension.