The food pyramid is commonly taught in American schools as the “ideal” diet.
It was started as a sales tactic to boost grain sales, but was marketed as scientific research. And since this was started decades ago, you couldn’t simply google their sources to verify whether or not the studies were legit.
Turns out it’s a crock of shit, and teaching it to kids does make childhood obesity rates worse. Because of course it does, an excess of carbs is horrible for you.
Because it was sponsored by grain industries. Similar to the “breakfast is the most important meal of the day!” and “milk is good for your bones!” myths.
Had to learn this pyramid but never applied it. I mean, what did people eat for millions of years? Grains, roots, vegetables and fruits from foraging and now and then a ton of flesh (you can count dairy as extra-fatty flesh). So a lot of full-grain, vegetables and inbetween fruits and once or twice the week flesh and dairy it is for me.