Two fast-food chains now offer trans fat free menu options in their U.S. restaurants. This week both KFC and Taco Bell switched to cooking oils that do not contain the bad fat.

KFC has stopped using oil containing trans fat to cook its chicken, opting instead for soybean oil. Taco Bell now uses canola oil and soybean oil to cook 23 of its food items and plans to eliminate trans fat from all of its menu items in the near future. Executives at the companies say taste has not been compromised by switching to healthier oils.

Taco Bell and KFC are the first fast-food chains in the U.S. to eliminate trans fats from their foods. Other chains, including McDonald’s and Burger King, have promised to use healthier cooking oils but have yet to make the switch. Trans fats are considered to be unhealthy because they raise bad cholesterol levels which contribute to serious health conditions like coronary artery disease.