I wonder what the value is of that advice, it's so incredibly vague. What's "varied"? What's "moderated"? Feels a bit like an excuse to stay ignorant.
I think point is less to stay ignorant and more to focus on macro-level changes (water > soda/beer, vary your starches, get sugar from fruit, avoid "filling up" on purely protein) rather than obsessing over this or that micronutrient and trying to boil it all down into a perfect formulation that you consume in a sludgy pancake-batter-tasting "shake" twice a day.