The food guide pyramid, informally known as the food pyramid, and formally titled the Improved American Food Guide Pyramid is a historical nutrition guide published in 1992 by the USDA to replace the earlier food groups classification system. The food guide pyramid suggested optimal nutrition guidelines for each food category, per day, using a mnemonic graphic of a pyramid with horizontal dividing lines, to represent suggested percentages of the daily diet for each food group. The food guide pyramid was superseded by the current USDA nutrition advisory program titled "MyPyramid" in April 2005.