Oak Brook, Ill.-based fastfood giant McDonald's has introduced a new cooking oil in its 13,000 US restaurants, which will reduce the levels of trans fatty acids (TFAs) in its French fries by 48%, reduce saturated fat by 16% and dramatically increase polyunsaturated fat by 167%. While the total fat content in the fries remains unchanged, health experts agree that reducing TFAs and saturates while increasing polyunsaturates is beneficial to heart health.