Sign up for CNN’s Eat, But Better: Mediterranean Style. Our eight-part guide shows you a delicious expert-backed eating lifestyle that will boost your health for life . CNN  —  The battle over the health merits of various cooking fats has never really gotten below a simmer — but it’s starting to heat up again. Beef tallow and other animal fats, including pig lard and butter, were traditionally used as the main cooking fats in the United States up until the early 20th century. A shift occurred