The four rules of healthy eating are: Eat a balanced diet; limit saturated fats, trans fats, and sodium; choose foods high in fiber, vitamins, and minerals; and watch your portion sizes. Eating a balanced diet means eating foods from the five food groups: grains, vegetables, fruits, proteins, and dairy products. Limiting foods high in saturated fats, trans fats, and sodium helps reduce the risk of heart disease, stroke, and other health problems. Choosing foods high in fiber, vitamins, and minerals is important for maintaining energy levels and a healthy weight. Lastly, it is important to watch your portion sizes and not overeat, since that can lead to weight gain.