Nit: Children haven't been taught the food pyramid in something like a couple of decades I think. Current model is something like the DailyPlate visual - a plate filled proportionally with various things.
Definitely agree with the concern here, but this is not a problem unique to the food pyramid.
Children will be taught all kinds of propaganda if they attend a public school.
It's part of the cost, just not the part that is taken from tax dollars.
I've seen this over and over - adults assuming that what happens in schools today is the same their childhood experience in the classroom, frozen in time.
Parents of school-age children ranting and raving about how the school needs to stop doing X, when it hasn't been that way forever; and they cannot hear it, cannot absorb it, cannot stop talking about it. Something something childhood trauma.
Maybe adults, but probably not the people who were taught the food pyramid - children.
Edit: changed the tense to acknowledge this was in the past. Thought that was obvious since the food pyramid was a thing of the past.