At an event Monday at its headquarters here, McDonald’s announced several changes to its ingredients, including eliminating artificial preservatives from some breakfast foods and Chicken McNuggets, its most popular food item, and removing high-fructose corn syrup from its buns.
Such changes, together with its decision in 2015 to buy only chicken raised without antibiotics used to treat humans, affect almost half of the food on McDonald’s menu, the company said.
The moves are the latest in a series by the company to address changing demands by consumers, who have pushed food companies and restaurants to provide more healthy options and fewer artificial ingredients. It is also an effort to play defense against numerous competitors who promote the quality and freshness of their foods.
Mike Andres, president of McDonald’s U.S.A., said that over the last few years, the company took a hard look at its foods and how they were prepared. The ingredients it was using, like artificial preservatives and high-fructose corn syrup, had good reasoning behind them — but consumers disliked them.
“Why take a position to defend them if consumers are saying they don’t want them?” Mr. Andres said on Monday.
Jessica Foust, director of culinary innovation at McDonald’s, hosted a group of reporters in a test kitchen to show how some of the changes will work in practice.
On the table in front of her were the five ingredients that go into an Egg McMuffin: an English muffin, a large egg, a slice of Canadian bacon, McDonald’s proprietary American cheese and butter — no longer liquid margarine.
The margarine used to be squirted out of a plastic bottle. The butter the company will use has to be softened but not melted, then blended to maintain its flavor and consistency.
The change took six months. “You have to be careful with butter,” Ms. Foust said. “We’re really cooking with real ingredients.”
Other changes, like getting artificial preservatives out of Chicken McNuggets, were easier — all the company had to do was take the preservative out of the oil it cooked them in. That change has been made. The changes to the buns will happen this month.
Marion Gross, senior vice president for supply chain at McDonald’s, said the sheer volume of ingredients that McDonald’s needs every day made it difficult to change quickly.
So the company is increasingly testing new products and ingredients in regional markets, which allows it to develop larger supply chains over time. It is, for instance, testing Latino-inspired breakfast bowls in Southern California, like an egg white scramble with sautéed baby spinach and kale, and a scrambled egg with cheese and chicken chorizo, garnished with McDonald’s hash browns.
Many of the new ingredients it is starting to buy, like cage-free eggs and antibiotic-free chicken, are more expensive. But Ms. Gross said that would not cause prices to rise. “We are confident we can offset the premium,” she said.
McDonald’s is determined to continue to keep its prices steady, Mr. Andres said, noting that the costs of its major commodities like beef and chicken are down this year.
After a rough patch, the company has regained its financial footing in recent quarters, helped in large part by making many of its breakfast menu items available throughout the day. But the growth from that change appears to be slowing down, putting pressure on the company to find new ways to increase sales.
In its second quarter, the company reported that sales in stores open at least a year, or same-store sales, grew just 1.8 percent in the United States, less than investment analysts had expected. Globally, same-store sales rose 3.1 percent.
Earnings were flat at $1.09 billion, compared with $1.2 billion in the same period a year earlier.
One of the ways to get more customers, Mr. Andres said on Monday, is to talk more openly about foods in an effort to change consumer attitudes toward McDonald’s.
“We’re going to continue to follow up and continue to inform customers — we told you we were going to do this, and here’s where we are on that,” he said.
For instance, the company announced that all of its chicken would be antibiotic-free by 2017, but on Monday, it said it had already reached that goal.
“We’re proud of the changes we’re making,” Mr. Andres said.