” do your research”
” I can provide scientific facts” – but does not haha

This usually a Bro masquerading as someone interested in evidence.. he is aware of the new evidence based approach but is not skilled enough or knowledgeable to explain it.. or to support it.

2, The guys that offers another persons opinion as a proof statement

” My Dr said”
” a book or documentary or website”

Quality of evidence ranges from poor to the gold standard..
One mans opinion communicated verbally, of in a written format no matter how credentialed is considered as very poor quality of evidence for its still just one mans opinion.

Quality evidence begins.. when its given a critical review by other experts in the field before being allowed to be published

3, The guys that makes statements backed by a link to a research paper

Very fair and reasonable, most guys with credentials fall here..

The challenge is now we need to talk about the quality of that paper and its relevance to our specific discussion.

ie is it a mechanistic study?
in humans or rats ?
are there other studies that offer conflicting data ?
Is there are a Meta-analysis or Systematic Review available ie a summary of all the studies on this subject ?
etc etc etc

4, The guys that offers not only a a link to a paper but his own breakdown and review of that research ..

Research Reviews etc

That guy is usually going to have a commercial back end offering which IMO is totally reasonable.

Honestly

I pay no attention to personality 1 or 2

Victor Black