Ah, but the doctor who lost is the one who was suing. He has not been successfully sued for calling people quacks.
Perhaps he lacks good judgement in when to pick fights. I don't know. I don't need his opinion to know that diet is not the cause of all disease.
Well, calling people quacks is hardly something to be sued about. If that were not so, many people here would have the socks sued off of them.
Something actionable in that vein involves a known falsehood, I believe.
I would like to see the assertion "diet is the cause of all disease" pointed out to me.