Food pyramid poster

The US Food Pyramid poster was in classrooms from the 1970s onward

The US Food Pyramid poster was in classrooms from 1992 onward

On the classroom wall

Most Americans are familiar with the Food Pyramid, a graphic showing the optimal number of servings for various food types which appeared in most schools for decades.

The image is actually a standard, and was introduced in 1992 by the US Dept of Agriculture, USDA, and titled the "Food Guide Pyramid".

This comes as quite a surprise to many people who were at school way before that date, but still remember it exactly as seen today.

Sweden, 1974

The idea of some kind of chart illustrating good diets goes back quite a while, but early ones were just lists or tables. The idea of an actual triangle, with the express intent to show the reduced quantities in the narrower parts as it moved up, was first shown as a pyramid in Sweden in 1974. This appeared in the Vi magazine from KF. The idea proved popular, and in subsequent years it spread across Europe through to the Far East, not arriving in the US officially until 1992.

A modified USDA food pyramid was proposed for adults over 70 in 1999, and the main one itself was updated in 2005 and 2011.

It's not clear why so many people distinctly remember seeing the chart so many years before 1992. It's possible some locl enterprising nutrition-aware teachers made their own, but unlikely in the numbers being discussed, and in any case hitting on the idea specifically of a pyramid, with no reference to any previous designs, seems a far stretch to happen so many times. It could be the adults remembering it actually saw them on the walls of their own kids classrooms, "in the background", without really noticing them, then later this unconscious memory came to light when they actually through about where they first saw them - the answer being "on a classroom wall", i.e. when I was at school.