> Not everyone with formal training is an expert, but its the minimum requirement. Literally no one without formal training can be an expert in such a complex topic as heart disease.

I have no bone in this particular fight. I'm inclined to agree with you, most of the time, but it's clearly possible to be an expert in nearly anything without formal training:

https://en.wikipedia.org/wiki/Srinivasa_Ramanujan

Lots of absolutes in this discussion, but reality is usually far more nuanced.

It depends, if looking for advise on how to use excel from someone, I don't think that they need to be certified or whatever.

For asking someone to do some web design or a logo, I don't think it's necessary either, but there is a limit somewhere.

Think about this way, if you yourself or someone in your family would have heart disease, would you take advice from an acupuncturist?

I bet you wouldn't. What are the odds that Kris Kresser without any formal training or experience managed to better understand the science behind such a complex topic like heart disease than full-time scientists and cardiologists?

Self-learning is great for a lot of things, but heart disease is likely not one of them.