Dietary recommendations are a key element in the management of cardiovascular disease. Evidence is mounting that certain dietary patterns can influence cardiovascular health by modifying risk factors such as obesity, dyslipidemia, and hypertension, as well as factors involved in systemic inflammation, insulin sensitivity, oxidative stress, endothelial function, thrombosis, and cardiac rhythm.1,2 In recent years, numerous dietary fads have emerged, in part as a response to the rising prevalence of obesity in the United States.3 In the present study, we review the various dietary portfolios that have emerged in the literature and the major studies that investigated their effectiveness in modifying cardiovascular risk. Currently, the typical American diet is estimated to derive 49% of its calories from carbohydrates, 34% from fat, and 12% to 16% from protein.4 Proposals to alter the proportions and/or types of macronutrients in this diet have been made for weight loss and cardiovascular health (Table 1).5–12 For weight management, for example, the strategy recommended by most medical groups entails the intake of a low-calorie, low-fat diet. The concept of fat restriction for weight management stems from traditional calorimetric measurements, which assign greater energy values to fat (&9 kcal/g) and less to carbohydrate and protein (&4 kcal/g). The low-calorie concept, on the other hand, is an intuitive technique to induce negative energy balance and has been adopted by some commercialized weight loss programs such as Weight Watchers International. View this table: TABLE 1. Various Dietary Patterns, Including Those Popularized Commercially and Those Investigated by Observational Studies and Clinical Trials One alternative proposed for weight loss is the low-carbohydrate diet. This was first described by William Banting13 in the 1860s and recently has received much attention in the form of the Atkins’, Stillman, Protein Power Lifeplan, and Zone diets. The Atkins’ diet begins with a weight-loss …