(Reuters) - The Trump administration on Monday relaxed some rules aimed at making U.S. school lunches healthier, a move viewed by health advocates as a direct hit on former first lady Michelle Obama’s signature issue.

FILE PHOTO: U.S. Secretary of Agriculture Sonny Perdue (C) talks to the media at the White House in Washington, U.S. April 25, 2017. REUTERS/Yuri Gripas

U.S. Agriculture Secretary Sonny Perdue, in one of his first acts after his Senate confirmation last week, signed a proclamation that postpones sodium reductions, makes it easier to serve foods without whole grains, and allows the return of chocolate- and strawberry-flavored milk with fat.

“Certain aspects of the standards have gone too far,” said Perdue, speaking at an elementary school in Virginia.

The change comes as Donald Trump, one of the more fast-food-friendly presidents in recent years, has vowed to slash regulation.

The 2010 Healthy, Hunger-Free Kids Act was championed by Michelle Obama and became a rallying cry for her critics after it set school lunch maximums for calories, cut sodium and artery-clogging trans fat, and required more fruits, vegetables and whole grains.

The federally funded U.S. school lunch program, started by President Harry Truman in the 1940s, is overseen by the U.S. Department of Agriculture and feeds more than 30 million, mostly low-income, children.

Healthy lunch proponents expressed the most concern about relaxing efforts to reduce excessive dietary sodium, which is linked to high blood pressure, heart attack and stroke.

“This will lock in very high levels of sodium in school lunches,” said Margo Wootan, director of nutrition policy for Center for Science in the Public Interest.

The sodium limit for a high school lunch is now about 1,400 milligrams, or three-fourths of the recommended daily maximum, Wootan said.

Perdue’s proclamation delays plans to reduce that to 1,080 milligrams this school year. The ultimate target is about 740 milligrams in the 2022 school year, Wootan said.

“Federal nutrition programs should provide nutritious food - that’s just good government, not nanny state policies run amok,” said Wootan, who added that many schools have adopted the standards and worked through early problems with ingredient availability and taste.

The School Nutrition Association, which represents both the industry that sells food to schools and cafeteria workers, has lobbied to weaken the rules, particularly with regard to sodium.

Many large food companies are suppliers to the U.S. school lunch program, including Tyson Foods Inc, Cargill Inc [CARG.UL] and General Mills Inc. Domino’s Pizza Inc delivers to schools as part of its “Smart Slice” program.