After lagging behind other fast food chains like Wendy's, KFC and Taco Bell, Burger King is finally hopping on the bandwagon.
It originally announced in July 2007 that it will make a full switch by December 2008, but has brought forward the deadline.
"Our suppliers were able to manufacture enough quantity to get us there sooner than our committed deadline," said Chief Executive and Chairman John Chidsey.
All items, including baked ones, on the menu will be free of the substance. Trans-fat oil is used to extend the shelf-life and preserve the flavour of food.
According to doctors, it can raise bad cholesterol and lower healthy cholesterol, increasing the risk of heart disease.
Burger King has already eliminated the oil in the majority of restaurants, and feedback has been positive. Chidsey said the customers either couldn't tell the difference, or preferred the new taste.
He refused to divulge what's replacing trans-fat oil in food, saying that it's exclusive information.
Burger King is not the last in making the change though; McDonald's Corp has also not yet fully converted their oils, especially in their baked products, and they say they will do so by year's end.