McDonald's stopped using lard for fries in 1990.
In 1990, McDonald's stopped using lard for fries and switched a vegetable oil blend after health campaigns pressured McDonald's to reduced cholesterol, although the change significantly altered the McDonald's fries texture and taste.
Before the year 1990, McDonald's fries were cooked in a blend of 93% beef tallow and 7% cottonseed oil, which gave the McDonald's fries their signature flavor.
Although in 1990, amidst health concerns about saturated fats, McDonald's announced that they would cook their fries in 100% vegetable oil.
A campaign businessman Phil Sokolof targeted the cholesterol in fast food, which led to the change, which made the McDonald's fries cholesterol free and lower in fat, but also less flavorful of many people who were used to the old better taste.
McDonald's also made some further changes to their recipe for their fries in 2002 and 2007 to eliminate trans fats from their cooking oils, and eventually McDonald's started using a blend of cooking oils with soybean oil and natural beef flavoring to mimic the original taste.