General Mills Inc said on Tuesday that it had reduced sodium by at least 20 percent in seven product categories, fewer than it had targeted, as part of the food industry's effort to cut back on an ingredient said to increase the risk of serious illnesses.

The maker of brands like Cheerios cereal and Yoplait yogurt said in 2010 that it was targeting a 20 percent reduction in 10 product categories by 2015. The results would be compared with a 2008 baseline.

The company has reached its goal in all but three categories. It cut sodium by 18 percent in cereal and by 19 percent in both its Progresso ready-to-serve soups and Old El Paso Mexican dinners.

The biggest reductions came in savory snacks at 35 percent and frozen pizza at 29 percent.

According to the American Heart Association, excess sodium consumption can increase risk of stroke, heart disease and other health problems. In 2010, the National Academies’ Institute of Medicine issued a report outlining ways to reduce intake and recommended that the U.S. Food and Drug Administration set mandatory national standards to lower content in foods gradually.

The FDA has yet to issue benchmarks, but companies ranging from Kraft Heinz Co, formerly Kraft Foods, to Wal-Mart Stores Inc have announced voluntary plans to reduce sodium in products they sell.

General Mills called its results a success and noted that 20 percent was an ambitious target. Some product reformulations took months or even years, said Chief Health and Wellness Officer Maha Tahiri.

"It's very significant for a nutrient like sodium because it really defines a lot of the taste," Tahiri said in an interview. "We did it in a very, very mindful way."

But some health advocates said the industry had not done enough to reduce public consumption. "Clearly, some companies have been making significant progress, but it's nowhere near enough to protect the public's health," said Michael Jacobson, executive director of the Washington non-profit Center for Science in the Public Interest.

He said that while there had been modest reductions of sodium in some products over the past decade, others had been reformulated to contain even more.