Margarine is always better for you than butter. Not always true. Many margarines contain trans-fatty acids. Choose soft tub margarine over stick to avoid the trans fats. Read the labels and avoid products that contain partially hydrogenated shortenings.
Vegetarian diets are naturally low in fat.
Some vegetarian diets replace meat with cheese and eggs as a primary protein source and can contain a lot of fat, especially saturated fat. Eating less cholesterol is the best way to lower your cholesterol. Eating less saturated fat is the dietary key to reducing blood cholesterol levels. Many of these substitutes, such as the non-dairy creamers and desserts, are loaded with saturated fat. Soy-based products, such soy cheese and cream cheese, also contain significant amounts of fat.