They probably weren't in primary schooling in the last 11 years. They were probably taught the food pyramid over my plate, and disagreed with it.
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.