Inside the familiar pyramid shape, rainbow-colored bands representing different food groups run vertically from the tip to the base. The old pyramid's sections ran horizontally.
Agriculture Secretary Mike Johanns called it "a system of information to help consumers understand how to put nutrition recommendations into action."
Officials hope the new symbols will renew interest in healthy habits but acknowledged that it will take time to make a difference in America's growing girth.
People have steadily grown fatter since the food pyramid debuted in 1992. A report last month in The New England Journal of Medicine contended that obesity, particularly in children, was causing a reversal in life expectancy, shaving four to nine months off the average life span.
Johanns said the 1992 pyramid had "become quite familiar, but few Americans follow the recommendations." He said that knowledge about nutrition and food consumption patterns has grown significantly in the past dozen years and is reflected in the new food guidance symbols.
"If we don't change these trends, our children may be the first generation that cannot look forward to a longer life span than their parents," said Eric Bost, the Agriculture Department's under secretary for food, nutrition and consumer services
The new guide is just one element of a system aimed at making people slimmer and healthier, said Eric Hentges, director of the Center for Nutrition Policy and Promotion. Also in store are Internet tools to help follow the new recommendations, as well as tools to help educators and nutritionists spread the word.
"Part of the problem previously was that we had this one symbol, this one pyramid, and it was one size fits all," Hentges told agriculture reporters last week. "Or it was a misinterpretation. In the case of grain servings, it said six to 11 servings. Well, if you're supposed to be eating 1,600 calories, you never did get to choose these 11 servings of grain.
"Who knows what a serving is?" Hentges added. "It's whatever I put on my plate. The servings differ for you than for your spouse, maybe."