Complex sentence: Diets high in saturated fat, found mainly in meat and high-fat dairy products, increase the risk of heart disease, diabetes, and stroke, and may increase the risk of certain types of cancer.
Split into simpler sentences: Diets high in saturated fat, found mainly in meat and high-fat dairy products, increase the risk of heart disease, diabetes, and stroke. What's more, a high-fat diet may increase the risk of certain types of cancer.