You are correct but OP is pointing to generally recommended controversies, backed by FDA and other agencies by 'research', running for decades. I wouldn't bet much on somebody holding a title being automatically correct.
If we as mankind don't know these super-complex effects that can take half a lifetime to manifest, no amount of titles will get you closer to truth.
I said nutritionists but should have said 'nutrition science'. Thanks for pointing it out.
That varies heavily from state to state. It's anywhere from no regulations (e.g., New Jersey) all the way to only licensed dieticians may provide individualized nutritional counseling at all (e.g., Georgia). In general, states lean towards the latter.
Not sure about the USA, but in Canada the requirements to become a registered dietician include a B. Sc. and writing a standard exam, whereas there are no requirements to call yourself a nutritionist.