Let me pose this another way, why would you expect me to change the amount of bread i eat because of another year education? I already had 13 years of teachers telling me it should be the foundation of my diet and it didn’t stick. Why would the next year of education be any different?
I wouldn't expect another year of English literature, calculus, and nuclear physics courses to teach me anything about biology, civics, or textile manufacturing that I could apply to my day-to-day life, either—but a year of education in nutrition science, the practical workings of government, and traditional spinning and weaving techniques? That makes a huge difference.
So you appear to agree with the consensus of experts that grains should not be the basis of your diet. This has been the us governments recommendation for over a decade (https://en.m.wikipedia.org/wiki/MyPlate)
If what you're saying is "I disagree with expert consensus from the 80s", well then sure, but so does the expert consensus! That's how the scientific process works (slowly).
To achieve that, you needed to have enough confidence in yourself and your ability to measure and feel stuff (which some people think is bad, apparently) versus some consensus which purports to know better.
Courageous new science regularly blasts old knowledge and education to bits, and that's a good things.
If "knowledge" was only what you were presented in primary school, the world would be a very different place.