"Want to know a little-known fact about McDonald’s french fries? Before McDonald’s started using hydrogenated vegetable oils to fry its fries, the company used good, old-fashioned beef tallow.

Many other fast food restaurants did, too, including Burger King, Wendy’s, Hardee’s, Arby’s, Dairy Queen, Popeyes and Bob’s Big Boy.

For centuries, tallow (or beef fat) was considered a healthy and delicious fat for frying, baking and more. It was only once cheap, highly processed vegetable oils became widely available in the U.S. and elsewhere that tallow and similar animal fats (like schmaltz and lard) went out of fashion"
https://draxe.com/nutrition/tallow/