The Food and Drug Administration says knowledge about nutrition has evolved since the early 1990s, and labels need to reflect that.
Michael Taylor, FDA deputy commissioner for foods, said 20 years ago "there was a big focus on fat, and fat undifferentiated."
Since then, health providers have focused more on calories and warned people away from saturated and trans fats rather than all fats. Trans fats were separated out on the label in 2006.
The FDA has been working on the issue for a decade, Taylor said.
Nutritionists and other health experts have their own wish list for label changes.
The number of calories should be more prominent, they say, and the amount of added sugar and percentage of whole wheat in the food should be included.
They also want more clarity on serving sizes.
The Center for Science in the Public Interest said there is concern the labels have not been as effective as they could be.
Some evidence indicates that more people are reading the labels in recent years.