The US Department of Agriculture has been issuing food recommendations for more than a century, dating back to 1894. It published bulletins, guide books, posters, pamphlets, and other materials with varied consumer acceptance over the years. In the early 1980’s the USDA decided a move from text to graphics was desirable. The Food Wheel was published in 1984, but was not widely received. In 1992 the USDA conducted consumer studies to help determine how an updated guide should look, and the Food Pyramid was born; at least that is the official story.
You may find this interview interesting. https://youtu.be/ZxtqqS51zK8