General Mills Starts Making Some Cheerios Without GMOs General Mills Inc. GIS -0.28%has started producing Cheerios free of genetically modified content, making the 73-year-old breakfast cereal one of the highest-profile brands to change in the face of growing complaints over such ingredients from activist groups and some consumers. The change—which only affects original Cheerios, not other varieties like Honey Nut Cheerios—has been in the works since about a year ago, when General Mills began working to change manufacturing for Cheerios to eliminate ingredients containing genetically modified organisms, or GMOs. The company started manufacturing the GMO-free cereal several weeks ago, and expects it to be available to consumers "shortly," once the products have made their way through the distribution system and onto shelves. The Cheerios will carry the label "Not Made With Genetically Modified Ingredients," though the company notes that they could contain trace amounts due to contamination in shipping or manufacturing. Critics of GMO use in foods called attention to the Cheerios move Thursday, hailing it as a major victory. Advocacy groups have raised concerns about possible health problems from eating foods with GMOs, which are crops like corn grown from seeds genetically engineered for desirable traits like pest resistance. The groups have promoted consumer campaigns in some states to mandate labeling of GMOs in food, and targeted specific brands—including Cheerios—and to change their policies. Most big food companies have rebuffed such efforts, arguing that there is no evidence of any health problems resulting from GMOs despite decades of use. The food companies also generally have refused voluntarily labeling, saying it is costly and will give consumers a misconception that GMOs are harmful. "There is broad consensus that food containing GMOs is safe, but we decided to move forward with this in response to consumer demand," said Mike Siemienas, spokesman for General Mills. The Minneapolis-based company said it chose Cheerios because the primary ingredient is oats, a crop that isn't grown from genetically modified seeds, so the transition just required it to find new sources of cornstarch and sugar. "Even that required significant investment," Mr. Siemienas said. He didn't provide a figure, but said that the hurdles would make it "difficult, if not impossible" to make Honey Nut Cheerios and other varieties without GMOs. GMO Inside, a campaign that advocates GMO labeling, said Cheerios is the first major brand of packaged food in the U.S. to make the switch from containing GMOs to marketing itself as non-GMO. Some foreign countries have restricted GMO use in food for years. Other companies have also said they plan to change. Whole Foods Market Inc. said it will require by 2018 that all food in its stores containing GMOs, disclose the fact on labels. Chipotle Mexican Grill Inc. and Kellogg Co.'s Kashi, which markets its cereals and snacks as having "natural ingredients," have both said they are working on taking GMOs out of their food. But it is a lengthy and expensive process. Kashi says only 1% of U.S. cropland is organic and around 70% of packaged foods contain GMOs.