The FDA wants to change what counts as "healthy" food. Big food makers say that's unfair.

As the federal government moves to change rules for what foods can sport "healthy" labels, manufacturers are pushing back.

Some of the biggest makers of cereals, frozen and packaged food have submitted dozens of claims to the Food and Drug Administration objecting to new rules that would exclude food with high amounts of added sugar and salt from being labeled as "healthy" on packaging. Some manufacturers have even called the regulations unconstitutional, saying they violate companies' First Amendment rights. 

The FDA last fall moved to update its requirements around what foods can use the word "healthy" on packaging — the first change since the rule was implemented in the 1990s. The proposed changes would leave out high-sugar, low-fat products that currently are allowed to use the healthy label today, such as fruit-flavored low-fat yogurts and Raisin Bran cereal.