Not all fats are created equal. Scientists have known since the 1950s that replacing saturated fats with unsaturated ones can have profound health benefits . Diets that are high in solid fats, such as butter and animal fat, lead to elevated risks of cardiovascular disease and high cholesterol. But it has been difficult to phase out saturated fats--not only are they are delicious, they are also important components of a food's structure. Without saturated fat, ice creams are just sugary liquids and a hot dog has the consistency of a pet’s chew toy.