The U.S. Agriculture Department has revised the familiar food pyramid, hoping to make it simpler. But critics say the "new, improved" pyramid might as well be in hieroglyphics.

Called MyPyramid, the new version looks like a vertical rainbow, with different colored bands running up and down. Each color represents a different food group. The widest band, orange, represents grains -- so consumers are supposed to somehow figure out that they should be eating more grains.

This would all be simpler if only the graphic included some labels that indicated what each color stands for. But the USDA said that would have been too confusing.

There is, however, a flight of stairs, with an intrepid runner working his or her way up, symbolizing the importance of exercise.

Agriculture Secretary Mike Johanns called the pyramid a "customized, interactive food guidance system."

"MyPyramid is about the ability of Americans to personalize their approach when choosing a healthier lifestyle that balances nutrition and exercise," Johanns told a news conference.

"Many Americans can dramatically improve their overall health by making modest improvements to their diets and by incorporating regular physical activity into their daily lives."

"This new symbol is a missed opportunity," said Margo G. Wootan, Nutrition Policy Director of the Center for Science in the Public Interest. "USDA seems to have bent over backward to avoid upsetting any particular commodity group or food company by not showing any foods that Americans should eat less of."

The pyramid is supposed to represent the government's latest set of dietary guidelines, unveiled in January, but it's not clear it does that.

"The pyramid and shape will be tough for people to understand, at least initially," Sonja Tuitele of Wild Oats Markets, a chain of natural food stores, told the Chicago Sun-Times.

Wootan said the pyramid was a step back from the relatively strong nutrition guidelines issued in January.

"By replacing one pyramid with 12, the government has made this advice more complicated than it needs to be. There are simple key principles about healthy eating that truly do work for all Americans, and those could have been represented on one symbol," she said.

The USDA commissioned a Web site -- that is perhaps more effective at communicating the ideas behind the pyramid. The site enables consumers to work out an individual diet plan based on their age, weight and other factors.