The cardiac diet, also known as a heart-healthy diet, emphasizes the consumption of nutrient-rich foods while avoiding saturated fats, trans fats, excessive sugar, and sodium to reduce the risk of cardiovascular disease. It aims to lower cholesterol levels and promote overall health, with recommended foods including fruits, vegetables, lean dairy, and sources of omega-3 fatty acids. Key foods to avoid include fried items, high-fat meats, and processed sugars.