The type of dietary fats that should be limited in a healthy diet are saturated fats and trans fats. Saturated fats are typically found in animal-based products and certain oils, while trans fats are often present in processed foods and margarine. High consumption of these fats can lead to an increase in LDL cholesterol levels, which is associated with a higher risk of heart disease and stroke. Instead, individuals should focus on incorporating healthier fats, like monounsaturated and polyunsaturated fats, found in foods like avocados, nuts, and olive oil.